CoordenaÃÃo de AperfeÃoamento de Pessoal de NÃvel Superior / A cistite hemorrÃgica (CH) Ã um evento inflamatÃrio frequentemente associado ao uso das oxazafosforinas. NÃs demonstramos que amifostina (AMF) pode prevenir o dano tecidual provocado pela ifosfamida (IFO). Sabendo-se que IFO tambÃm altera a funÃÃo motora do trato urinÃrio inferior, o presente trabalho foi realizado com o objetivo de investigar se AMF protege os animais contra as alteraÃÃes da funÃÃo vesical provocadas por IFO, e se este efeito ocorre atravÃs de mecanismos dependentes do Ãxido nÃtrico (NO) e dos canais de potÃssio sensÃveis ao ATP (KATP). Camundongos Swiss machos (25-30g, n=8) receberam salina (CTR)ou IFO (400mg/kg, ip) para induÃÃo de CH. Outro grupo recebeu, 30min antes de IFO, AMF (50mg/kg, sc), aminoguanidina (AMG, 50 mg/kg, ip), ODQ (2 mg/kg, vo) ou glibenclamida (GLI, 10 mg/kg, ip). Outros grupos receberam, 30min antes de AMF, L-arginina (L-ARG, 600 mg/kg, ip), ODQ ou diazÃxido (DIAZ, 2mg/kg, ip). Em outra seÃÃo, os grupos que receberam AMG foram prÃ-tratados com L-arginina e os que receberam GLI foram prÃ-tratados com diazÃxido, ambos com intervalos de 30 mim. O peso Ãmido vesical (PUV) e os parÃmetros macroscÃpicos e histopatolÃgicos foram analisados 12h apÃs a injeÃÃo de IFO. Em experimentos ex vivo, preparaÃÃes de mÃsculo liso vesical foram mantidas em soluÃÃo fisiolÃgica aerada com 95% de O2 â 5% CO2, pH 7.4 e a 37&#8304;C para registro isomÃtrico das contraÃÃes musculares a soluÃÃes despolarizantes de cloreto de potÃssio (KCl) e carbacol (CCh). Para o registro de pressÃo intravesical (PIV) por cistometrograma contÃnuo (CC), foi realizada uma laparatomia e um catÃter de polietileno fixado na bexiga e exteriorizado pela regiÃo abdominal foi conectado a um sistema de infusÃo contÃnua de salina (0.04mL/min) e a um transdutor de pressÃo acoplado a um sistema de aquisiÃÃo de sinais biolÃgicos. Nos animais tratados com AMF o aumento PUV provocado por IFO foi inibido em 83%. L-ARG e DIAZ nÃo preveniram tal efeito de IFO no PUV (1.1% e 11.4%, respectivamente). Os escores macro e microscÃpicos foram significativamente menores em AMF, comparados ao grupo IFO. L-ARG e DIAZ inibiram os escores de AMF. IFO diminuiu a contratilidade de tiras de bexiga ao CCh em relaÃÃo ao grupo CTR (1.36 Â 0.24 Vs 0.18 Â 0.02 g forÃa/mg de tecido seco; p<0.01). AMF preveniu a hipocontratilidade provocada por IFO ao estÃmulo com CCh (1.47 Â 0.16 g forÃa/mg de tecido seco; p<0.01). L-ARG e DIAZinibiram o efeito de AMF (0.6 Â 0.08 e 0.79 Â 0.12 g forÃa/mg de tecido seco, respectivamente; p<0.01 em relaÃÃo a AMF). Na anÃlise por CC, AMF reverteu o aumento da frequÃncia miccional (FM) provocada por IFO (18 Vs 5.6 micÃÃes/15 min, IFO e CTR, respectivamente; p<0.01. AMF â 6.5 micÃÃes/15 min; p<0.01 em relaÃÃo a IFO). L-ARG e DIAZ reverteram as FMs de AMF (p<0,01) (L-ARG: 14.5 e DIAZ: 11.2 micÃÃes/15 min). Os traÃados cistometrogrÃficos de CTR e AMF mostraram ciclos miccionais regulares com contraÃÃes evidentes associadas ao esvaziamento da bexiga. Nas anÃlises de CC de animais tratados com IFO, os traÃados mostraram ciclos irregulares de micÃÃo e nÃo foram observadas contraÃÃes evidentes associadas ao evento da micÃÃo. DIAZ tambÃm apresentou traÃados com este padrÃo. O tratamento com ODQ nÃo alterou o efeito sobre a disfunÃÃo vesical in vitro e in vivo promovida por IFO e nem sobre a proteÃÃo pela AMF. AMF inibe as alteraÃÃes motoras vesicais promovidas por IFO atravÃs de processos mÃltiplos que provavelmente incluem o NO e KATPs, sem envolver, no entanto, a geraÃÃo de GMPc. / Hemorrhagic cystitis (HC) is an inflammatory event often associated with the use of oxazafosforins. We have demonstrated that amifostine (AMF) may prevent tissue damage caused by ifosfamide (IFO). Considering that IFO also changes the motor function of the lower urinary tract, the present study aimed to investigate whether AMF protects animals against IFO-related bladder dysfunction, and if this effect occurs through anitric oxide (NO) and ATP-sensitive potassium channels (KATP) dependent mechanism. Male Swiss mice (25-30g, n = 8) were given saline or IFO (400mg/kg, ip) to induce HC. Another group received, 30min before IFO, AMF (50mg/kg, sc), aminoguanidine (AMG, 50 mg/kg, ip), ODQ (2 mg/kg, po) or glibenclamide (GLI, 10 mg/kg, ip ). Other groups received 30min before AMF, L-arginine (L-ARG, 600 mg/kg, ip), ODQ or diazoxide (DIAZ, 2mg/kg ip). In another experimental setting, the groups that received AMG were pretreated with L-arginine and those receiving GLI were pretreated with diazoxide each drug administered at intervals of 30 min. Bladder wet weight (BWW) and macroscopic and histopathological parameterswere analyzed 12h after IFO injection. Inin vitro assays, bladder smooth muscle preparations were kept in saline solution aerated with 95% O2 - 5% CO2, pH 7.4 and at 37 &#8304; C for isometric muscle contractions record the depolarizing solutions of KCl and carbachol (CCh). For the record of intravesical pressure (IVP) by continuous cystometrogram (CC), laparotomy was performed and a polyethylene catheter attached to the bladder and exteriorized through the abdominal region was connected to a system of continuous infusion of saline (0.04mL/min) and a pressure transducer coupled to an acquisition system biological signals. In animals treated with AMF,BWW was reduced by 83% when compared with IFO-injected mice. L-ARG and DIAZ did not preventIFO-induced BWW effect (1.1% and 11.4%, respectively). Macroscopic and microscopic criteria were significantly reduced in AMF injected mice versus IFO group. L-ARG and DIAZ failed to prevent such criteria in comparison to IFO group. IFO decreased bladder strips contractility response to CCh versus control group (1.36 Â 0.24 Vs 0.18 Â 0.02 g force / mg of dry tissue, p <0.01). AMF prevented the IFO-related decrease in contractility response (1.47 Â 0.16 g force / mg of dry tissue, p <0.01). L-ARG and DIAZ did not alter IFO effect bladder contractility (0.6 Â 0.08 and 0.79 Â 0.12 g force / mg dry tissue, respectively, p <0.01 compared to saline control). In CC analysis, AMF reversed the increased voiding frequency (VF) caused by IFO (18 Vs 5.6 micturition/15 min, IFO and CTR, respectively, p <0.01. AMF â 6.5 micturition/15min; p <0.01 compared to IFO). The VFs in L-ARG and DIAZ (14.5 and 11.2 micturition/15min, respectively) were significantly different from AMF group, p <0.01. Cystometrography recordings of control and AMF groups showed regular micturition cycles with evident contractions associated with bladder emptying, which as markedly different from IFO-injected animals that presented an irregular trace concerning micturition cycles and no evident contractions associated with the urination event. DIAZ also showed similar patterns to that of IFO. Treatment with ODQ did not alter either the in vitro and in vivo effects on bladder dysfunction promoted by IFO or upon protection by AMF. AMF inhibited IFO-related functional alterations in bladders through multiple processes that probably include NO and KATPs without involvingthe generation of cGMP.

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / Oxaliplatina (OXL) à um agente platÃnico de 3 geraÃÃo com potente atividade citotÃxica em diversos cÃnceres. Tem como toxicidade limitante uma neuropatia sensitiva perifÃrica (NSP) de inÃcio agudo, tornando-se crÃnica com doses cumulativas. Amifostina (AMF) à um agente antioxidante de largo espectro, que vem sendo atualmente estudado na citoproteÃÃo dos efeitos adversos da radioterapia e quimioterapia do cÃncer. Esta pesquisa objetivou avaliar o efeito da AMF sobre a hiperalgesia mecÃnica plantar e alodinia tÃrmica, assim como sobre as alteraÃÃes histopatolÃgicas e imunoexpressÃo de marcadores, tais como a proteÃna c-Fos, caspase 3, IL-1, nitrotirosina, NOSi, NOSn e NMDA, observadas na NSP experimental induzida por OXL. O estudo foi aprovado pelo Comità de Ãtica em Pesquisa Animal da Universidade Federal do CearÃ, com o protocolo 27/08. Camundongos Swiss machos (25-35g) foram tratados com OXL (1mg/kg, i.v.) e prÃ-tratados com AMF (1, 5, 25, 50 ou 100mg/kg, s.c.) por 4,5 semanas, paralelamente aos testes nociceptivos. A alodÃnia tÃrmica foi avaliada pelo teste de imersÃo da cauda em Ãgua fria (10ÂC) e a hiperalgesia mecÃnica plantar pelo teste do Von Frey EletrÃnico. Foi realizada a anÃlise histopatolÃgica e imunohistoquÃmica de amostras obtidas do corno dorsal da medula espinhal lombar dos animais em 24h, 7, 14, 21 e 28 dias. Demonstrou-se que a OXL diminuiu significativamente o limiar nociceptivo mecÃnico e tÃrmico, a partir do 21 dia (p<0,001) e 14 dia (p<0,01), respectivamente, quando comparados ao grupo controle. O tratamento com AMF inibiu esses efeitos em todas as doses testadas (p<0,001), sendo a dose de 25mg/kg aquela com efeito mais significativo. No teste do Rota-Rod nÃo foi observada variaÃÃo significativa entre os grupos, indicando ausÃncia de comprometimento motor. Na anÃlise histopatolÃgica foram observados edema do tecido nervoso e atrofia dos neurÃnios nos animais tratados com OXL, o que nÃo ocorreu nos animais prÃ-tratados com AMF. Observou-se a imunoexpressÃo importante de c-Fos, caspase 3, NOSn, NOSi e nitrotirosina nos animais tratados apenas com OXL, e uma imunoexpressÃo reduzida do receptor NMDA, quando comparado com o grupo controle. AMF reduziu a expressÃo de c-Fos e de nitrotrosina, mas nÃo da caspase 3, NOSn e NOSi, e aumentou a expressÃo do receptor NMDA. NÃo houve imunoexpressÃo de IL-1 nos grupos testados. Embora preliminares, os dados sugerem que a AMF promoveu uma importante proteÃÃo nas alteraÃÃes sensitivas da NSP induzida por OXL, desde que inibiu a hiperalgesia e a alodinia, alÃm da imunoexpressÃo de c-Fos. Adicionalmente AMF promoveu importante aÃÃo protetora nas lesÃes teciduais, sendo capaz de exercer aÃÃo antioxidante e antiapoptÃtica, atravÃs da inibiÃÃo da expressÃo de nitrotirosina e do aumento da expressÃo do receptor NMDA, respectivamente. / Oxaliplatin (OXP) is a third-generation platinum agent with potent cytotoxic activity in several cancers. Its limiting toxicity is a sensory peripheral neuropathy (SPN) of acute onset, which becomes chronic after cumulative doses. Amifostine (AMF) is a broad spectrum antioxidant and is currently being studied as a cell-protecting agent against the adverse effects of radiotherapy and chemotherapy in cancer patients. This study was aimed to evaluate the effect of AMF on plantar mechanical hyperalgesia and thermal allodynia, as well as on histopathological alterations and immune expression of markers such as c-Fos protein, caspase 3, IL-1, nitrotyrosine, iNOS, nNOS and NMDA, observed in experimental OXL-induced SPN. The study was approved by the Ethics Committee on Animal Research, Federal University of CearÃ, through protocol 27/08. Male Swiss mice (25-35g) were treated with OXL (1 mg/kg, i.v.) and pre-treated with AMF (1, 5, 25, 50 or 100 mg/kg, s.c.) for 4,5 weeks, in addition to the performance of nociceptive tests. Thermal allodynia was evaluated by tail immersion in cold water (10ÂC), and plantar mechanical hyperalgesia by the Electronic Von Frey test. The histopathological and immunohistochemical analysis of samples taken from the dorsal horn of the lumbar spinal cord of the animals was performed in 24 hours, 7, 14, 21 and 28 days. OXP significantly decreased mechanic and thermal nociceptive threshold since 21th day (p<0,001) and 14th day (p<0,01), respectively, when compared to control group. AMF treatment inhibited these effects in all doses tested (p<0,001), and the dose of 25mg/kg had the most significant effect. Locomotor impairment was not evidenced through Rota-Rod test. Furthermore, we observed edema and neurons atrophy in dorsal horn of OXP group, not showed in AMF group. OXP group had overexpression of c-Fos, caspase 3, nNOS, iNOS, and nitrotyrosine, but a reduced NMDA receptor expression when compared to control group. AMF group had hypoexpression of c-Fos and nitrotyrosine and increased NMDA receptor expression, but not altered caspase 3, nNOS and iNOS expression. There was no immunoexpression of IL-1 in the tested groups. Although preliminary, the data suggest that AMF promoted an important protection in OXL-induced SPN sensory changes, since it inhibited the hyperalgesia and allodynia, as well as the immunoexpression of c-Fos. Additionally AMF promoted significant protective action on tissue lesions, being able to exert antioxidant and antiapoptotic action by inhibiting the expression of nitrotyrosine and increasing expression of NMDA receptors, respectively.

Amifostine (WR-2721, delivered as Ethyol) is a radioprotector agent that reduces the likelihood of early and/or late biological effects by eliminating free radical particles during ionizing radiation fraction (radiotherapy). It activates in under normal tissues conditions to reduce mutation and fraction in DNA. Among 4000 prodrug compounds, amifostine is the only agent has been approved from the US Food and Drug Administration in clinical purposes. The main effective mechanisms of amifostine are based on scavenging for free radical, improving for DNA repair step and indication of cellular hypoxia. In the same time, this drug is not widely used around the world for different reasons mainly its high cost and toxicity level (lethal dose). Conjugating a monoclonal antibody with amifostine by a suitable linker is a process of Antibody Drug Conjugate producing immuno-radioprotector molecule hypothesis. Administrated molecule is an approach of targeted delivery therapy that increases the dosage uptake into particular area of treatment to minimize the dose distribution in non-targeted area in the body. In the present work, we proposed a three-compartment system model to simulate the two-pore theory pathway of an immuno-radioprotector molecule when it is crossing the physiological barriers. The model investigated its distribution and elimination in porous media (with both large and small pores) within a pharmacokinetics compartmented model approach.

Amifostine (WR-2721, Ethyol®), a phosphorylated thiol, demonstrates the unique ability to protect normal but not tumour tissue from cytotoxic damage induced by radiation therapy and chemotherapy. This study tested the effect of amifostine's active metabolite, the free thiol, WR-1065, on the cytotoxicity of standard anticancer drugs against human A2780 ovarian and MCF7 breast cancer cell lines in vitro, using the well-characterised sulphorhodamine B assay. 50% inhibitory concentration (IC50) values were determined for each of 16 different anticancer drugs in the presence and absence of the highest nontoxic dose of WR-1065 from concentration-response curves constructed in triplicate and based on 18 replicate cell culture plates for each tested drug concentration. Pretreatment with WR-1065 had no statistically significant effect on the IC50 value of any of the 16 drugs tested against either the A2780 or MCF7 human tumour cells. These data expand upon previous reports showing that amifostine does not protect tumours from the cytotoxic effects of anticancer agents. The ability of amifostine to protect against dose-limiting toxicity to a variety of normal tissues without protection of tumour should enhance the efficacy ratio of a wide range of standard anticancer drugs.

nÃo hà / Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / IntroduÃÃo: A Doxorubicina (DOX), antineoplÃsico antracÃclico, à largamente utilizada no tratamento dos mais diversos tipos de tumores sÃlidos e neoplasias hematolÃgicas. A Cardiotoxicidade provocada pelo uso de antibiÃticos antracÃclicos tem sido observada hà algumas dÃcadas como fator agravante e limitante do uso terapÃutico da DOX. Apesar do conhecimento de inÃmeros fatores que podem mediar a induÃÃo da cardiotoxicidade pela DOX, os mecanismos fisiopatolÃgicos continuam nÃo esclarecidos. Objetivo: Avaliar o efeito da amifostina e glutationa na cardiotoxicidade aguda induzida por doxorubicina e estudar a morfologia do tecido cardÃaco de camundongos tratados com doxorubicina por microscopia de forÃa atÃmica. Material e MÃtodos: Camundongos C57BL/6 fÃmeas (n=8) foram tratados com doxorubicina (25mg/Kg i.p.) ou salina (0,2mL i.p.) e sacrificados 96 horas apÃs tratamento. Outro grupo experimental foi tratado com amifostina (AMF 25, 50 e 100 mg/Kg s.c.), glutationa (GLT 125, 250 e 500mg/Kg s.c.) ou salina 30 mim antes da injeÃÃo de doxorubicina, no caso da glutationa a administraÃÃo foi diÃria atà o dia do sacrifÃcio. Os parÃmetros analisados foram: eletrocardiograma, Ãndices cardÃaco e esplÃnico, dosagem de grupos sulfidrilas nÃo protÃicos, dosagem de CK e CK-MB, parÃmetros histolÃgicos, dosagem por ELISA de TNF-&#61537;, IL-1&#61538;&#61484; expressÃo por imunohistoquÃmica de TNF-&#61537;, IL-1&#61538;, iNOS, apoptose e anÃlise por microscopia de forÃa atÃmica. Resultados: O tratamento com AMF nas doses de 50 e 100mg/Kg e GLT 250 e 500 mg/Kg foi capaz de aumentar a percentagem de sobrevivÃncia dos animais que foram submetidos a cardiotoxicidade aguda induzida por DOX (25 mg/Kg) quando comparados com o grupo injetado somente com DOX. A AMF e GLT tambÃm foram capazes de prevenir, em comparaÃÃo ao grupo DOX (p<0,05), as alteraÃÃes nos valores eletrocardiogrÃficos, (aumento do QRS e QTc e diminuiÃÃo da amplitude de R), as alteraÃÃes nos Ãndices cardÃacos e esplÃnicos, a elevaÃÃo dos nÃveis sÃricos das enzimas CK e CK-MB, a reduÃÃo dos nÃveis de grupos sulfidrilas nÃo protÃicos no tecido cardÃaco e as alteraÃÃes histolÃgicas (degeneraÃÃo hidrÃpica e vacuolizaÃÃo, focos de hialinizaÃÃo de fibras cardÃacas, picnose e necrose) induzidas pela DOX (25mg/Kg). A DOX induziu aumento da marcaÃÃo imunohistoquÃmica para cÃlulas apoptÃticas e expressÃo de iNOS e diminuiu a expressÃo de TNF-&#61537;. A AMF foi capaz de prevenir estas alteraÃÃes, sendo esta prevenÃÃo apenas discreta para a expressÃo de TNF-&#61537;. A microscopia de forÃa atÃmica revelou alteraÃÃes morfolÃgicas nÃo vistas pela microscopia Ãptica e mostrou ser uma ferramenta valiosa na avaliaÃÃo de efeitos de drogas. ConclusÃo: Nossos resultados sugerem o efeito citoprotetor da amifostina pelo aumento da atividade da glutationa peroxidase no tecido cardÃaco e que esta se mostra tÃo eficiente quanto a droga de referencia dexrazoxane. A utilizaÃÃo da microscopia atÃmica introduz uma ferramenta de anÃlise comparativa em escala nanomÃtrica, tornando possÃvel observar a destruiÃÃo membranar cardÃaco condizente com dano oxidativo. / IntroduÃÃo: A Doxorubicina (DOX), antineoplÃsico antracÃclico, à largamente utilizada no tratamento dos mais diversos tipos de tumores sÃlidos e neoplasias hematolÃgicas. A Cardiotoxicidade provocada pelo uso de antibiÃticos antracÃclicos tem sido observada hà algumas dÃcadas como fator agravante e limitante do uso terapÃutico da DOX. Apesar do conhecimento de inÃmeros fatores que podem mediar a induÃÃo da cardiotoxicidade pela DOX, os mecanismos fisiopatolÃgicos continuam nÃo esclarecidos. Objetivo: Avaliar o efeito da amifostina e glutationa na cardiotoxicidade aguda induzida por doxorubicina e estudar a morfologia do tecido cardÃaco de camundongos tratados com doxorubicina por microscopia de forÃa atÃmica. Material e MÃtodos: Camundongos C57BL/6 fÃmeas (n=8) foram tratados com doxorubicina (25mg/Kg i.p.) ou salina (0,2mL i.p.) e sacrificados 96 horas apÃs tratamento. Outro grupo experimental foi tratado com amifostina (AMF 25, 50 e 100 mg/Kg s.c.), glutationa (GLT 125, 250 e 500mg/Kg s.c.) ou salina 30 mim antes da injeÃÃo de doxorubicina, no caso da glutationa a administraÃÃo foi diÃria atà o dia do sacrifÃcio. Os parÃmetros analisados foram: eletrocardiograma, Ãndices cardÃaco e esplÃnico, dosagem de grupos sulfidrilas nÃo protÃicos, dosagem de CK e CK-MB, parÃmetros histolÃgicos, dosagem por ELISA de TNF-&#61537;, IL-1&#61538;&#61484; expressÃo por imunohistoquÃmica de TNF-&#61537;, IL-1&#61538;, iNOS, apoptose e anÃlise por microscopia de forÃa atÃmica. Resultados: O tratamento com AMF nas doses de 50 e 100mg/Kg e GLT 250 e 500 mg/Kg foi capaz de aumentar a percentagem de sobrevivÃncia dos animais que foram submetidos a cardiotoxicidade aguda induzida por DOX (25 mg/Kg) quando comparados com o grupo injetado somente com DOX. A AMF e GLT tambÃm foram capazes de prevenir, em comparaÃÃo ao grupo DOX (p<0,05), as alteraÃÃes nos valores eletrocardiogrÃficos, (aumento do QRS e QTc e diminuiÃÃo da amplitude de R), as alteraÃÃes nos Ãndices cardÃacos e esplÃnicos, a elevaÃÃo dos nÃveis sÃricos das enzimas CK e CK-MB, a reduÃÃo dos nÃveis de grupos sulfidrilas nÃo protÃicos no tecido cardÃaco e as alteraÃÃes histolÃgicas (degeneraÃÃo hidrÃpica e vacuolizaÃÃo, focos de hialinizaÃÃo de fibras cardÃacas, picnose e necrose) induzidas pela DOX (25mg/Kg). A DOX induziu aumento da marcaÃÃo imunohistoquÃmica para cÃlulas apoptÃticas e expressÃo de iNOS e diminuiu a expressÃo de TNF-&#61537;. A AMF foi capaz de prevenir estas alteraÃÃes, sendo esta prevenÃÃo apenas discreta para a expressÃo de TNF-&#61537;. A microscopia de forÃa atÃmica revelou alteraÃÃes morfolÃgicas nÃo vistas pela microscopia Ãptica e mostrou ser uma ferramenta valiosa na avaliaÃÃo de efeitos de drogas. ConclusÃo: Nossos resultados sugerem o efeito citoprotetor da amifostina pelo aumento da atividade da glutationa peroxidase no tecido cardÃaco e que esta se mostra tÃo eficiente quanto a droga de referencia dexrazoxane. A utilizaÃÃo da microscopia atÃmica introduz uma ferramenta de anÃlise comparativa em escala nanomÃtrica, tornando possÃvel observar a destruiÃÃo membranar cardÃaco condizente com dano oxidativo. / Introduction: Doxorubicin (DOX) is an antineoplasic anthracyclic agent used on the treatment of several solid tumors and hematological cancers. DOX-induced cardiotoxicity has been studied for decades as a limiting factor on the anticancer therapy with this drug. Despite the current knowledge concerning the mechanisms of DOX-induced cardotoxicity, its pathophysiology is still not clear. Purpose: To evaluate of the amifostine and glutathione citoprotective effect on the DOX-induced acute cardiotoxicity and to study the morphology of cardiac tissue through the use of atomic force microscopy as a tool. Materials and Methods: C57BL/6 female mice were treated with doxorubicin (25mg/Kg i.p.) or saline (0,2mL i.p.) and sacrificed 96 hours after treatment. In another experimental setting, mice were given amifostine (AMF 25, 50 e 100 mg/Kg s.c.), glutathione (GLT 125, 250 e 500mg/Kg s.c.) or vehicle, 30 mim before the administration of DOX, except glutathione that was injected daily. Analitical parameters included: electrocardiograms, cardiac and spleen indices, non protein suphidrils groups levels, CK and CK-MB cardiac enzymes levels, histological analysis, cardiac levels of (TNF-&#61537;, IL-1&#61538;, iNOS) determined by ELISA, immunohistochemistry for TNF-&#61537;, IL-1&#61538;, iNOS, apoptosis and atomic force microscopy tissue analysis. Results: AMF (100mg/Kg) and GLT (250 e 500 mg/Kg) treatments were able of improve the survival rate of animals in spite of the injection of DOX (25 mg/Kg) in comparison to DOX-treated only group (p<0.05). A AMF e GLT were also able to prevent electrocardiographic changes (rising of QRS e QTc and reduced R amplitude), changes in the cardiac and spleen indices, the augmentation of blood levels of CK e CK-MB, reduction of non proteic suphidrils groups levels, and histological changes induced by DOX (25mg/Kg). DOX induced the augmentation of the immunostaining for apoptotic cells and iNOS what was prevented by the administration of amifostine. The atomic force microscopy reveals morphological changes on the tissue organizational structure which is not possible to be observed through optical microscopy. Conclusion: Our results suggest that the amifostine citoprotective effect on DOX-induced acute cardiotoxicity is due the rising of glutathione peroxidase activity in the cardiac tissue. The citoprotective effect of amifostine is as efficient as the reference drug dexrazoxane. The use of atomic force microscopy as a new pharmacological tool for comparative analysis in nanometric scale allow us to observe DOX-induced membrane destruction what is suggestive of oxidative stress process. / Introduction: Doxorubicin (DOX) is an antineoplasic anthracyclic agent used on the treatment of several solid tumors and hematological cancers. DOX-induced cardiotoxicity has been studied for decades as a limiting factor on the anticancer therapy with this drug. Despite the current knowledge concerning the mechanisms of DOX-induced cardotoxicity, its pathophysiology is still not clear. Purpose: To evaluate of the amifostine and glutathione citoprotective effect on the DOX-induced acute cardiotoxicity and to study the morphology of cardiac tissue through the use of atomic force microscopy as a tool. Materials and Methods: C57BL/6 female mice were treated with doxorubicin (25mg/Kg i.p.) or saline (0,2mL i.p.) and sacrificed 96 hours after treatment. In another experimental setting, mice were given amifostine (AMF 25, 50 e 100 mg/Kg s.c.), glutathione (GLT 125, 250 e 500mg/Kg s.c.) or vehicle, 30 mim before the administration of DOX, except glutathione that was injected daily. Analitical parameters included: electrocardiograms, cardiac and spleen indices, non protein suphidrils groups levels, CK and CK-MB cardiac enzymes levels, histological analysis, cardiac levels of (TNF-&#61537;, IL-1&#61538;, iNOS) determined by ELISA, immunohistochemistry for TNF-&#61537;, IL-1&#61538;, iNOS, apoptosis and atomic force microscopy tissue analysis. Results: AMF (100mg/Kg) and GLT (250 e 500 mg/Kg) treatments were able of improve the survival rate of animals in spite of the injection of DOX (25 mg/Kg) in comparison to DOX-treated only group (p<0.05). A AMF e GLT were also able to prevent electrocardiographic changes (rising of QRS e QTc and reduced R amplitude), changes in the cardiac and spleen indices, the augmentation of blood levels of CK e CK-MB, reduction of non proteic suphidrils groups levels, and histological changes induced by DOX (25mg/Kg). DOX induced the augmentation of the immunostaining for apoptotic cells and iNOS what was prevented by the administration of amifostine. The atomic force microscopy reveals morphological changes on the tissue organizational structure which is not possible to be observed through optical microscopy. Conclusion: Our results suggest that the amifostine citoprotective effect on DOX-induced acute cardiotoxicity is due the rising of glutathione peroxidase activity in the cardiac tissue. The citoprotective effect of amifostine is as efficient as the reference drug dexrazoxane. The use of atomic force microscopy as a new pharmacological tool for comparative analysis in nanometric scale allow us to observe DOX-induced membrane destruction what is suggestive of oxidative stress process.

Amifostine is the only approved radioprotective agent by the Food and Drug Administration for reducing the damaging effects of radiation on healthy tissues. In this study, the effects of ionizing radiation on rat liver microsomal membrane and brain tissue and the protecting effects of amifostine on these systems were investigated at molecular level. Sprague-Dawley rats, which were administered amifostine or not, were whole-body irradiated and liver microsomal membranes and different regions of the brain of these rats were analyzed using FTIR spectroscopy, FTIR microspectroscopy and synchrotron FTIR microspectroscopy. The first part of this study revealed that ionizing radiation caused a decrease in the total lipid content and CH2 groups of lipids, an increase in the carbonyl esters, olefinic=CH and CH3 groups of lipids in the white matter and grey matter regions of the brain, which could be interpreted as a result of lipid peroxidation. In addition, radiation altered the protein structure of the brain. Amifostine caused significant protective effect against all the radiation induced damages in the brain. In the second part of the study, FTIR results showed that radiation induced a decrease in the lipid/protein ratio and a degradation of lipids into smaller fragments that contain less CH2 and more carbonyl esters, olefinic=CH and CH3 groups in microsomal membranes. In addition, radiation caused an alteration in the secondary structure of proteins, an increase in lipid order and a decrease in the membrane dynamics. Amifostine prevented all the radiation induced compositional, structural and functional damages in the liver microsomal membranes.

Diss. (sammanfattning) Linköping : Univ., 2003. / Härtill 5 uppsatser.

Patienten mit metastasierten Keimzelltumoren, die einen Progress oder ein Rezidiv ihrer Erkrankung nach einer cisplatinhaltigen Vortherapie erleiden, haben eine schlechte Prognose. Unter Verwendung einer erneuten konventionellen Chemotherapie können maximal 15-30% dieser Patienten geheilt werden, so dass die Mehrzahl der Patienten an ihrer Erkrankung verstirbt. Aus diesem Grund ist die Optimierung der therapeutischen Möglichkeiten ein wesentliches Ziel. Unsere Daten zeigen, dass die Hochdosischemotherapie (HDCT) eine wesentliche therapeutische Verbesserung darstellt und mittels dieser Therapie mit einem ereignisfreien Überleben von 30-60% zu rechnen ist. Eine "matched-pair" Analyse konnte im Hinblick auf das ereignisefreie und das Gesamtüberleben einen Vorteil von mehr als 10% zu Gunsten der HDCT feststellen. Darüber hinaus hat die zunehmende Erfahrung und die Verwendung von peripheren Blutstammzellen und hämatopoetischen Wachstumsfaktoren, den Einsatz der HDCT deutlich sicherer gemacht. Aus den genannten Gründen sollte alle Patienten mit Rezidiv oder Progress eines Keimzelltumors der HDCT zugeführt werden. Die operative Entfernung von residuellen Tumormanifestationen (RTR) nach primärere Chemotherapie ist heute Standard bei Patienten mit metastasierten Keimzelltumoren. Zwar findet sich in der histologischen Aufarbeitung bei den meisten Patienten ausschließlich nekrotisches Gewebe, doch werden bei einem Teil der Patienten auch Anteile von reifem Teratom und vitalen differenzierten und undifferenzierten Karzinomen gefunden. Während die Resektion von Nekrose keinen therapeutischen Benefit für den Patienten darstellt, ist die komplette Entfernung von reifem Teratom oder Zellen eines Karzinoms für die Prognose entscheidend. In Bezug auf die HDCT konnten bisher keine vergleichbaren Daten erhoben werden. Zur Evaluierung des Stellenwertes der RTR nach HDCT analysierten wir unser eigenes Patientenkollektiv und fanden, dass vergleichbar zur Primärtherapie alle Patienten nach Salvage-HDCT, die eine partielle markernegative oder markerpositive Remission erreicht haben, einer RTR zugeführt werden sollten. Bis auf intrazerebrale Reste sollten alle residuellen Tumormanifestationen komplett reseziert werden. Neben der Optimierung der therapeutischen Möglichkeiten ist auch die Minimierung der chemotherapieassoziierten Toxizitäten ein wesentlicher Bestandteil meiner wissenschaftlichen Arbeit. Aus diesem Grund evaluierten wir die Wirksamkeit der Substanz Amifostin im Hinblick auf die Verringerung von Toxizitäten, die Wirkung auf die Mobilisierung von peripheren Blutstammzellen und den Einfluß auf die Rekonstitution des Immunstatus bei Patienten mit rezidivierten oder progredienten Keimzelltumoren, die mittels einer konventionellen Chemotherapie und anschließender HDCT behandelt wurden. Der Einsatz von Amifostin erbrachte in diesem Zusammenhang und in diesem Patientenkollektiv keinen therapeutischen oder prophylaktischen Nutzen, so dass dessen Verwendung bei Patienten mit Keimzelltumoren nicht generell empfohlen werden kann. / Overall, patients with relapsed or progressive germ cell tumors (GCT) after cisplatin-based chemotherapy have a low chance of cure. Using conventional-dose chemotherapy as salvage treatment only 15-30% of the patients will become long-term survivors. It is well known that the majority of these patients will ultimately die of their disease. Therefore, improvment of standard treatment is clearly desirable. Our data has been established high-dose chemotherapy (HDCT) as an effective salvage modality with an event-free survival of 30-60%. A matched-pair analysis showed an advantage for HDCT compared with conventional-dose chemotherapy with improvement in event-free and overall survival of more than 10%. Furthermore, due to increasing clinical experience in the management of side-effects, the use of peripheral blood progenitor cells, and the availability of hematopoietic growth factors, HDCT has become relatively safe. In GCT patients with relapsed or rogressive disease HDCT has been demonstrated as a feasible and safe treatment concept which will be curative for a substantial proportion of these patients. Therefore, HDCT should be administered in patients with first relapse and unfavorable prognostic factors and as second or subsequent salvage treatment. Surgical resection of residual tumors (RTR) after first-line chemotherapy is recommended in patients with metastatic GCT. Necrosis will be the only histological finding in the majority of these patients. However, in others mature teratoma, viable cancer consisting of residual GCT, non germ-cell tumors, undifferentiated cancer or a combination of these histologies may be found. Whereas the resection of necrosis offers no therapeutic benefit, resection of mature teratoma or viable cancer adds to long-term event-free and overall survival in these patients. However, limited data exist on the results of surgery and the respective histologies in patients after first or subsequent salvage treatment with HDCT. To assess the contribution of RTR in this setting, we retrospectively analyzed a cohort of patients who had been treated with HDCT for relapsed or refractory GCT. Our data show that RTR contributes to the overall treatment outcome and should be offered to all patients with a partial remission after HDCT. Complete resections of all residual tumors outside the CNS should be attempted. Furthermore, we assessed the efficacy of amifostine for protection from chemotherapy-induced toxicities, for peripheral blood progenitor cell mobilization and for immune-reconstitution in patients treated with conventional-dose paclitaxel, ifosfamide, cisplatin (TIP) and high-dose carboplatin, etoposide and thiotepa (CET) followed by PBPC rescue. In conclusion, amifostine additional to conventional-dose chemotherapy or HDCT showed no unequivocal advantage in protection from treatment-related toxicities and had no effect neither on PBPC mobilization nor on immune-reconstitution.

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / Cisplatina (cisdiaminodicloroplatinum) à um agente quimioterÃpico freqÃentemente usado para o tratamento de vÃrias linhagens de neoplasias, mormente as de cabeÃa e pescoÃo. Contudo, a ototoxicidade permanece sendo um dos efeitos colaterais causadores de significativa morbidade e que freqÃentemente limita sua utilizaÃÃo. O objetivo principal deste trabalho foi desenvolver um modelo experimental para o estudo da ototoxicidade por cisplatina em ratos e, nesse modelo, avaliar se a apoptose fazia parte dos mecanismos de lesÃo celular. Buscou-se ainda averiguar se o modelo desenvolvido era viÃvel para estudos de otoproteÃÃo. Foram utilizados ratos Wistar machos aos quais se administrou cisplatina por via intraperitoneal (IP) nas doses de 24 mg/kg, fracionada em trÃs doses diÃrias de 8 mg/kg ou 16 mg/kg em infusÃo Ãnica. Os animais foram avaliados atravÃs de emissÃes otoacÃsticas evocadas produtos de distorÃÃo (EOAPD) ou potenciais auditivos evocados de tronco encefÃlico (PAETE) no terceiro (D3) e quarto (D4) dias apÃs o inÃcio da infusÃo das drogas. Ao final da avaliaÃÃo funcional auditiva, um grupo de animais teve suas cÃcleas removidas para estudo morfolÃgico por microscopia Ãptica em coloraÃÃes por hematoxilinaeosina (HE) e imunohistoquÃmica para apoptose pelo mÃtodo TUNEL e para detecÃÃo de caspase 3. A um grupo de animais injetados com cisplatina 24 mg/kg foi realizada uma administraÃÃo prÃvia de amifostina via IP na dose de 240 mg/kg, dividida em trÃs doses diÃrias de 80 mg/kg/dia. Os animais tratados, diferente de seus controles, apresentaram uma significativa reduÃÃo de peso a partir do primeiro ou segundo dia apÃs a administraÃÃo das drogas, que nÃo foi diferente para ambas as doses. A mortalidade foi baixa atà o terceiro dia, mas aumentou significativamente no quarto dia. O grupo tratado com 24 mg/kg mostrou diminuiÃÃo significativa da amplitude das EOAPD e aumento do limiar eletrofisiolÃgico pelo PAETE no D3 e D4. A dose de 16 mg/kg nÃo foi capaz de promover reduÃÃo significativa da amplitude das EOAPD, mas promoveu elevaÃÃo do limiar auditivo dos animais, detectado atravÃs de PAETE. As lesÃes cocleares verificadas no estudo morfolÃgico se deram na estria vascular e nas cÃlulas ciliadas externas, e os escores de lesÃo foram significativamente maiores que nos grupos controle apenas com a dose de 24 mg/kg. A apoptose foi o mecanismo de lesÃo responsÃvel pela ototoxicidade da cisplatina na dose de 16 mg/kg quando os animais foram avaliados no D3. Jà em doses maiores (24 mg/kg) ou por um tempo mais prolongado de avaliaÃÃo (D4) outras vias de lesÃo celular estavam envolvidas. A amifostina promoveu proteÃÃo contra a otoxicidade causada pela cisplatina tanto na avaliaÃÃo funcional quanto na morfolÃgica. Assim, em ratos, a dose fracionada de 24 mg/kg de cisplatina com avaliaÃÃo funcional no terceiro dia apÃs o inÃcio da administraÃÃo por PAETE e morfolÃgica por microscopia Ãptica em coloraÃÃes por HE, constitui-se em um modelo viÃvel para estudos de ototoxicidade. TambÃm se presta para a pesquisa dos mecanismos envolvidos com tÃcnicas de imunohistoquÃmica e ainda para a avaliaÃÃo de drogas otoprotetoras. / Cisplatin (cis-diamminedicloroplatinum) is an antineoplastic drug frequently used in the treatment of a variety of cancers, specially the head-and-neck cancer. Ototoxicity, however, has been noted as a common side-effect of cisplatin, which may lead to significant interruptions in treatment, possibly impacting on local tumor control and patient survival. The aim of this work was to develop an experimental model in rats able to study the ototoxicity as a side effect of cisplatin and to perform otoprotection studies. In addition, we evaluated if apoptosis was involved in the cellular toxicity caused by cisplatin. Male Wistar rats were intraperitoneally (i.p.) treated with 24 mg/kg of cisplatin, which was divided into three equal doses (8mg/kg) or a single i.p. administration of 16 mg/kg. The animals were evaluated by distortion product otoacoustic emission (DPOAE) or brainstem evoked response audiometry (BERA) on the 3rd and 4th days after the cisplatin injection. After the functional hearing evaluation, a group of animals had their cochleas excised and processed for hematoxylin-eosin (HE) staining, terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labeling (TUNEL), and immunostaining with a caspase-3 antibody. In another set of experiments, amifostine (240 mg/kg. i.p. divided in three daily doses of 80 mg/kg) was administered immediately before the cisplatin (24mg/kg). Treatment with cisplatin caused a significant body weigh loss starting on the 1st or 2nd days when compared to non-treated animals. The mortality rate remained low until the 3rd day with significant enhance on day 4. The treatment with cisplatin 24 mg/kg, but not 16 mg/kg, resulted in a significant decrease of the DPOAE. Both doses promoted an increase of the hearing limiar detected by BERA on day 3 and 4. Morphological observations indicate cochlear lesions mainly in the vascular stria and outer hair cells. Only the scores of cochlear lesions of animals treated with the highest dose of cisplatin were significant different when compared to the non-treated group. Apoptosis was involved in the cellular toxicity caused by cisplatin 16 mg/kg, on day 3. In the highest dose or for more drawn out time, however, others mechanisms of cell toxicity must be involved. Amifostine prevented the cisplatin ototoxicity detected by functional evaluation as well as the morphological analysis. Thus, in rats, the intraperitoneal injection of cisplatin 24 mg/kg, divided into 3 equal doses, consist in a viable model for study of this adverse effect of cisplatin, with ototoxicity detected by functional evaluation with BERA and morphologic evaluation by optic microscopy for HE stains, in the third day after the beginning of the administration. Moreover, it is useful for the research of the involved mechanisms with immunostaining techniques, and still for the evaluation of otoprotective drugs.

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / INTRODUÃÃO: A amifostina (WR-2721) tem sido largamente estudada como agente citoprotetor em diferentes ÃrgÃos e contra os mais diversos agressores do organismo humano. Recentemente, um efeito gastroprotetor deste fÃrmaco foi observado em modelo de lesÃo gÃstrica induzida por indometacina (MOTA et al., 2007). OBJETIVOS: Este trabalho investigou o efeito da amifostina na lesÃo gÃstrica por etanol e o papel dos neurÃnios sensoriais aferentes, grupos sulfidrÃlicos nÃo-protÃicos, Ãxido nÃtrico, canais de potÃssio sensÃveis ao ATP e ciclooxigenase-2 nesse processo. MÃTODOS: Ratos Wistar foram tratados com amifostina (22,5, 45, 90 ou 180 mg/kg, v.o. ou s.c.). ApÃs 30 minutos, os animais receberam etanol absoluto (5 ml/kg v.o.). Decorridos 60 minutos da administraÃÃo de etanol, os animais foram sacrificados. Foram realizados estudos macroscÃpicos e histolÃgicos, bem como dosagem de grupos sulfidrÃlicos nÃo-protÃicos e de hemoglobina em fragmentos de estÃmago. Outros grupos foram prÃ-tratados com L-NAME (10 mg/kg i.p.), glibenclamida (10 mg/kg v.o.), celecoxibe (10 mg/kg v.o.) ou salina. ApÃs 30 minutos os ratos receberam amifostina (90 mg/kg v.o. ou s.c.) e depois de mais 30 minutos etanol absoluto (5 ml/kg), com sacrifÃcio ocorrendo 60 minutos depois. Um grupo de animais foi desensibilizado com capsaicina (125 mg/kg s.c.) entre 10 a 14 dias antes do protocolo de tratamento com amifostina. RESULTADOS: A amifostina preveniu de forma significativa o dano macroscÃpico causado por etanol no estÃmago nas doses de 45, 90 e 180 mg/kg quando administrada por via oral e 90 e 180 mg/kg quando utilizada por via subcutÃnea. Os parÃmetros histolÃgicos, edema, hemorragia e perda de cÃlulas epiteliais, tambÃm foram reduzidos (p<0,05) com o uso de amifostina. Os animais que receberam apenas etanol apresentaram nÃveis reduzidos de GSH no estÃmago. A amifostina reverteu esse efeito atravÃs de um estÃmulo à produÃÃo de novo de GSH ou pela prevenÃÃo do consumo destes grupos. A gastroproteÃÃo da amifostina na lesÃo induzida pelo etanol foi revertida pela administraÃÃo prÃvia de doses neurotÃxicas de capsaicina, mas nÃo pelo uso de L-NAME, glibenclamida ou celecoxibe. CONCLUSÃES: A amifostina protege a mucosa gÃstrica contra a injÃria induzida pelo etanol atravÃs de um aumento dos nÃveis de GSH e estimulaÃÃo de neurÃnios sensoriais aferentes no estÃmago. Esse efeito parece ser independente da ativaÃÃo de canais de potÃssio sensÃveis ao ATP e da atividade de Ãxido nÃtrico sintase e ciclooxigenase-2 / INTRODUCTION: Amifostine (WR-2721) has been widely tested as a cytoprotective agent against a number of aggressors in different organs. Recently, a gastroprotective effect was observed for this drug in a model of indomethacin-induced gastric injury (MOTA et al., 2007). OBJECTIVES: We investigated the effect of amifostine on ethanol-induced gastric injury and the role played by afferent sensory nerves, non-protein sulfhydryl groups, nitric oxide, ATP-sensitive potassium channels and cyclooxygenase-2 in the mechanism. METHODS: Wistar rats were treated with amifostine (22.5, 45, 90 or 180 mg/kg, p.o. or s.c.). Thirty minutes after amifostine administration, the animals were given 100% ethanol (5 ml/kg p.o.). Sixty minutes after ethanol administration the animals were euthanized. Macroscopic and histological studies were carried out and stomach fragments were retrieved and submitted to analysis for non-protein sulfhydryl groups and hemoglobin. Some animals were pretreated with L-NAME (10 mg/kg i.p.), glibenclamide (10 mg/kg p.o.), celecoxib (10 mg/kg p.o.) or saline solution. Thirty minutes after pretreatment the animals were given amifostine (90 mg/kg p.o. or s.c.) and, after another 30 minutes, 100% ethanol (5 ml/kg). The animals were euthanized 60 minutes later. Other rats were desensitized with capsaicin (125 mg/kg s.c.) 10-14 days before amifostine treatment. RESULTS: Amifostine treatment significantly reduced ethanol-induced macroscopic stomach injury at 45, 90 and 180 mg/kg p.o. and at 90 and 180 mg/kg s.c. The histological parameters (edema, hemorrhage and epithelial cell loss) were also reduced (p<0.05) when the animals were treated with amifostine. Animals receiving ethanol only presented reduced GSH levels in the stomach. Amifostine reverted this effect either by stimulating de novo GSH production or by preventing the consumption of GSH. Amifostine-promoted gastroprotection against ethanol-induced stomach injury was reversed by pretreatment with neurotoxic doses of capsaicin, but not by L-NAME, glibenclamide or celecoxib. CONCLUSIONS: Amifostine protects against ethanol-induced gastric injury by increasing GSH levels and stimulating the afferent sensory nerves in the stomach independently of ATP-sensitive potassium channels activation, nitric oxide synthase and cyclooxygenase-2 activity