Master of Science / Department of Kinesiology / Thomas J. Barstow / The accumulation of reactive oxygen species (ROS) has been linked to the development of muscular fatigue. Antioxidant administration has the potential to counteract the increased levels of ROS, leading to improvements in performance. N-acetylcysteine (NAC), a nonspecific antioxidant, is especially promising due to its ability to support the biosynthesis of glutathione, one of the primary endogenous antioxidants. Despite this, the effects of NAC on time to fatigue appear to be dependent upon the exercise intensity, with the more pronounced effects evident at submaximal exercise intensities. The purpose of this study was to determine the effects of an acute dose of NAC on whole body fatigue, critical power (CP) and W’ during high-intensity exercise. It was hypothesized that pretreatment with NAC would result in (1) an increase in time to fatigue (TTF), CP and W’, (2) NAC administration would attenuate changes in the EMG responses indicative of fatigue, and (3) speeding of the kinetics of the primary phase of VO2 and a reduction in the slow component. Seven healthy, active males (age: 21.4 ± 1.6 years, weight: 89.1 ± 11.0 kg, height: 183 ± 5 cm) completed an incremental ramp test until exhaustion for the determination of peak VO2 and power. Four tests were subsequently performed at power outputs corresponding to 80, 90, 100, and 110% Pmax under NAC and placebo (PLA) conditions. NAC resulted in a significant increase in [tGSH] in red blood cells compared to baseline and PLA condition. TTF was significantly increased only in the 80% Pmax trial (p = 0.033). CP was also significantly higher with NAC (NAC: 232 ± 28 W vs PLA: 226 ± 31 W; p = 0.032), but W’ showed a tendency to decrease (NAC: 15.5 ± 3.8 kJ vs W’: 16.4 ± 4.5 kJ). The change in W’ was negatively related to CP (r = -0.96), indicating that the increase in CP was associated with a decrease in W’. EMG analysis revealed a tendency for MdPF and RMS to demonstrate less of a change with NAC. There were no significant differences in VO2 kinetics, but an inverse relationship was observed between the change in τp and the magnitude of the slow component expressed both in absolute terms (r = -0.632, p = 0.007) and as a gain (r = -0.751, p = 0.0005). We conclude that NAC was effective in delaying fatigue and improving exercise performance at 80% peak power, although the exact mechanisms are still unclear.

Thesis (MSc)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: This thesis aims to determine whether supplementation with a grape-seed derived antioxidant, oligomeric proanthocyanidin (PCO) or the glutathione precursor, N-acetylcysteine (NAC) may prove beneficial as treatment for exercise induced muscle damage (EIMD) in athletes. In this double-blind cohort study, 21 healthy, uninjured male rugby-players in mid-season training phase, aged between 18 and 25 years were randomly divided into three treatment groups. Participants received 210 mg PCO, NAC or placebo treatment for 9 consecutive days. The study comprised a 6-day wash-out period (protocol days: -12 to -7), followed by a 6-day supplement loading period (protocol days: -6 to -1) a plyometric exercise intervention (protocol day 0) and continued supplementation for 2 days (protocol days: 1 to 2). The exercise intervention comprised 15 sets of 10 near maximal, vertical plyometric squat jumps. Blood samples and delayed onset of muscle soreness (DOMS) scores were collected on protocol days: -6, 0, 1 and 2. Assessments included serum creatine kinase (CK) activity, oxygen radical absorbance capacity (ORAC), malondialdehyde (MDA) and soluble vascular cell adhesion molecule-1 (sVCAM-1) concentrations over time as well as a differential circulating leukocyte count (neutrophils, lymphocytes, monocytes, eosinophils and basophils). Data analysis of CK activity revealed no significant differences between groups. However, PCO treatment prevented a significant peak in the CK response at 24 h (as seen in the placebo and NAC groups) when compared to baseline, pre and post readings (p<0.05). NAC supplementation significantly improved serum ORAC after the exercise intervention. By 48 h, serum ORAC had improved significantly from readings taken immediately post exercise (p<0.05) only in the NAC group. For all groups, absolute neutrophil counts peaked at 6 h post exercise from baseline or pre readings (p<0.05). In both NAC and placebo treated groups, neutrophil counts had decreased significantly in circulation by 24 h post exercise from the 6 h time-point (p<0.05). However, neutrophil counts only reached significantly lower levels by 48 h post exercise (p<0.05) in the group supplemented with PCO. The monocyte count also peaked significantly at 6 h post exercise when compared with other time-points before and after the exercise intervention (p<0.05) in all treatment groups. Neither antioxidant treatment significantly altered the responses of other leukocyte sub-populations, MDA or sVCAM-1 concentrations where main effects of plyometric exercise was evident. Although not statistically significant, a trend toward diminished sVCAM-1 expression with either antioxidant supplementation was apparent. These findings suggest that PCO supplementation (210mg/d) which includes a 7 day loading period may diminish plyometric EIMD by limiting (but not completely inhibiting) the neutrophil response. Secondary muscle damage may be prevented by partially blunting neutrophil infiltration, rather than only quenching free radicals released during the neutrophil oxidative burst. Furthermore, the finding that NAC supplementation improves serum ORAC only after exercise may provide added benefit when administered in combination with PCO. / AFRIKAANSE OPSOMMING: Hierde tesis is daarop gerig om vas te stel of aanvulling met ‘n druifsaadekstrak (DSE) gederiveerde antioksidant: pro-antosianiedoliese oligomeer (PSO), of die glutathione voorloopermolekule, N-asetielsistien (NAS) voordelig beskou kan word as behandeling vir atlete onderhewig aan spierskade veroorsaak deur oefening. Gedurende hierdie dubbelblinde kohort studie is 21 gesonde, manlike rugbyspelers sonder beserings tussen die ouderdom van 18 en 25 jaar in middel-seison fase ewekansig in drie behandelingsgroepe verdeel. Deelneemers het elk 210 mg PSO, NAS of placebo-aanvulling geneem vir nege agtereenvolgende dae. Die studie het bestaan uit ‘n 6-dag uitwasperiode (protokoldae: -12 tot -7), as ook ‘n 6-dag aanvullings periode (protokoldae: -6 tot -1), gevolg deur ‘n pliometriese oefeningsintervensie (protokol dag 0) en verdere aanvulling tot en met 2 dae na die oefening (protokol dae: 1 tot 2). Die oefeningsintervensie het 15 stelle van 10 naastenby maksimale, vertikale pliometriese hurkspronge behels. Bloedmonsters en vertraagde aanvang spierseerheid (VAS) tellings is op protokoldae: -6, 0, 1 en 2 geneem. Analiese het serum kreatien kinase (KK) aktiwiteit, suurstof radikaal absorpsie kapasiteit (SRAK), Malondialdahied (MDA) en oplospare vaskulêresel adhesie molekule-1 (oVAM-1) konsentrasie bepalings asook ‘n differentiële sirkulerende leukosiet seltelling ingesluit. KK aktiewiteit het geen merkwaardige verskil tussen groepe getoon nie. PSO aanvulling het wel gelei tot die voorkoming van ‘n merkwaardige piek in die KK response soos in die placebo en NAC behandelde groepe bevind is by die 24 h tydspunt in vergelyking met basislyn-, voor- en na-oefeningslesings (p<0.05). NAS het ‘n merkwaardige verbetering in serum SRAK getoon, maar eers teen 48 h na oefening. Slegs die NAS behandelde groep het op hierdie tydspunt ‘n betekenisvolle verbetering in SRAK getoon in vergelyking met lesings direk na oefening (p<0.05). Vir alle groepe is ‘n betekenisvolle toename in absolute neutrophiltellings waargeneem 6 h na oefening in vergelyking met basislyn- en vooroefeningslesings (p<0.05). Beide NAS en placebo-behandelde groepe het ‘n betekenisvolle afname in neutrophiltellings teen 24 h na oefening getoon in vergelyking met die 6 h tydspunt (p<0.05) maar met die PSO-behandelde groep word hierde afname eers teen 48 h waargeneem (p<0.05). Monosiettellings het in alle groepe 6 h na oefening ‘n betekinsvolle piek getoon (p<0.05). Waar slegs die hoofeffek van die pliometriese oefening betekenisvol was, het nie een van die twee antioksidant aanvullings ‘n merkwaardige verandering aan die respons van ander leukosiet sub-populasies, MDA of oVAM-1 konsentrasies getoon nie. Al kon statistiese beduidenheid nie bewys word nie, wil dit blyk dat ‘n verminderde oVAM-1 uitdrukking onstaan het in die geval van beide antioksidant-behandelde groepe. Tesame stel hierdie bevindinge voor dat PSO toediening (210mg/d) insluitende ‘n 7-dag aanvullingsperiode die vermoë verleen om die neutrophielrespons gedeeltelik te onderdruk (sonder om dit heeltemal te inhibeer) en sodoende spierskade verminder. Dus word verdere spierskade moontlik verlaag deur die voorkoming van neutrophil weefsel infiltrasie eerder as verwydering van reaktiewe spesies wat vrygestel word tydens oefening. Die bevinding dat NAS aanvulling serum SRAK eers na oefening merkwaardig verbeter, kan as voordelig beskou word, veral wanneer toegedien in samewerking met PSO om verdere spierskade te voorkom en herstelling vinniger te bewerkstellig.

A obstrução intestinal mecânica representa uma condição de urgência, necessitando diagnóstico precoce e terapêutica adequada, em virtude do seu elevado grau de morbidade e de mortalidade. Desta forma, o objetivo deste estudo foi avaliar o efeito da N-acetilcisteína associada ao Ringer lactato ou à solução salina hipertônica na resposta inflamatória, histologia e translocação bacteriana em modelo experimental de obstrução e isquemia intestinal. Para tanto, Foram constituídos quatro grupos experimentais, com 10 ratos Wistar em cada, além do grupo de referência: OI - Submetidos a obstrução e isquemia intestinal e enterectomia com anastomose intestinal, sem reanimação volêmica; RL - Submetidos a obstrução e isquemia intestinal, reanimação volêmica com Ringer lactato (32ml/kg, i.v., em 10 minutos) e enterectomia com anastomose intestinal; RLNAC - Submetidos a obstrução e isquemia intestinal, reanimação volêmica com Ringer lactato associado a NAC (32ml/kg + 150 mg/kg i.v. em 10 minutos) e enterectomia com anastomose intestinal; SHNAC - Submetidos a obstrução e isquemia intestinal, reanimação volêmica com solução salina hipertônica a 7,5% associado com NAC (4ml/kg + 150 mg/kg i.v., em 10 minutos) e enterectomia com anastomose intestinal. Grupo Referência (n=5): Animais anestesiados, submetidos a coleta de materiais para cultura e histologia e sacrificados por exsanguinação. Os animais receberam uma associação anestésica de cetamina e xilazina intramuscular em membro posterior direito, na dose de 60mg/kg e 10mg/kg, respectivamente. Decorridas 24 h do tratamento, a eutanásia foi realizada por exanguinação, sob anestesia, após a coleta dos tecidos / Mechanical intestinal obstruction represents a condition of urgency, necessary early diagnosis and appropriate therapy, due to their high degree of morbidity and mortality. In this way, the objective of this study was to evaluate the effect of N-acetylcysteine associated with lactated Ringer\'s or hypertonic saline solution in the inflammatory response, histology and translocation in an experimental model of intestinal obstruction and ischemia. For Four experimental groups were constituted with 10 Wistar rats each, in addition to the reference group: OI - submitted to obstruction and ischemia intestinal and enterectomy with intestinal anastomosis, without volume resuscitation; RL - Undergoing intestinal obstruction and ischemia, volume resuscitation with Ringer\'s lactate (32ml / kg, i.v., within 10 minutes) and anastomosis enterectomy intestinal; RLNAC - Undergoing obstruction and intestinal ischemia, resuscitation with lactated Ringer\'s lactating NAC (32 ml / kg + 150 mg / kg i.v. in 10 minutes) and enterectomy with intestinal anastomosis; SHNAC - Submitted to obstruction and intestinal ischemia, volume resuscitation with saline solution hypertension at 7.5% associated with CAP (4 ml / kg + 150 mg / kg i.v., in 10 minutes) and enterectomy with intestinal anastomosis. Reference Group (n = 5): Anesthetized animals, submitted to collection of materials for culture and histology and sacrificed by exsanguination. The animals received a anesthetic association of ketamine and intramuscular xylazine in limb posterior right, at the dose of 60mg / kg and 10mg / kg, respectively. After 24 h of treatment, euthanasia was performed by exsanguination, under anesthesia, after collection of tissues

Na infecção pelo HIV o equilíbrio entre antioxidantes e pró-oxidantes e a produção de citocinas encontram-se alterados, causando estresse oxidativo crônico. Presume-se que o estresse oxidativo crônico e a ativação do sistema imunológico favorecem a replicação do vírus através da ativação do NF-kB e a apoptose de células mononucleares do sangue periférico. O objetivo deste estudo foi avaliar o efeito da suplementação, durante 180 dias, com 600mg/dia de N-acetilcisteína (NAC), sobre a carga viral, os níveis de sub-populações de linfócitos, a viabilidade de linfócitos e sobre os níveis séricos de citocinas, proteínas, lipídeos, &#946;2 microglobulina e outros marcadores da ativação do sistema imunológico em pacientes assintomáticos, submetidos ao primeiro tratamento anti-retroviral. Participaram deste estudo, duplo cego controlado por placebo, que teve a duração de 180 dias, 30 indivíduos que iniciaram a terapia anti-retroviral. O grupo estudo foi constituído por 14 indivíduos que além do tratamento anti-retroviral foram suplementados com NAC, enquanto o grupo controle foi constituído por 16 indivíduos que além do tratamento anti-retroviral receberam placebo. Os marcadores avaliados foram determinados no dia anterior ao início do tratamento a que foram submetidos e após 60, 120 e 180 dias. Verificou-se aumento significante dos linfócitos CD4+, da relação CD4/CD8, de linfócitos viáveis, albumina, cisteína e glutationa, bem como diminuição significante dos níveis de TNF-&#945;, IL-8, haptoglobina e &#945;1-glicoproteína ácida, &#946;2-microglobulina, IgA e IgM, nos dois grupos estudados. Os níveis séricos de IL-6, colesterol total, LDL-colesterol, VLDL-colesterol e triglicerídeos não apresentaram alteração significante ao final deste estudo. Concluindo, a suplementação com 600 mg/dia de NAC, em pacientes submetidos ao tratamento anti-retroviral, não proporcionou benefícios adicionais àqueles decorrentes deste tratamento. / In HIV infection, the balance between antioxidants and pró-oxidants and the production of citokines are disturbed leading to a chronic state of oxidative stress and immune activation. It is presumed that HIV takes advantage of the proinflammatory and prooxidative environment to replicate through the NF-kB pathway leading to the apoptosis of peripheral blood mononuc1ear cells. The aim of this work was to study the effect of oral administration of N-acetylcysteine (NAC) 600 mg per day during 180 days on viral load, viability of lymphocytes, cytokines, proteins, lipids, &#946;2-microglobulin and other immune activation markers in asymptomatic patients under their first antiretroviral therapy. This was a double-blind, placebo-controlled study with 30 individuals who started antiretroviral therapy and were followed for 180 days. These individual were divided into two subgroups: the study group consisted of 14 participants who received NAC supplementation, whereas the control group had 16 individuals who received placebo. The studied markers were determined on the day before the beginning of treatment and after 60, 120 and 180 days of treatment. A significant increase was seen for CD4+ lymphocytes, the CD4/CD8 ratio, albumin, cysteine and glutathione; also, a significant reduction was found for levels of TNF-&#945;, IL-8, &#946;2 microglobulin, IgA, IgG, IgM, haptoglobin, and acid &#945;1-glycoprotein as a consequence of antiretroviral treatment. After 180 days of treatment, the levels of total protein, globulins and HDL-cholesterol presented significant alteration on1y in the control group, while the serum levels of IL-6, total cholesterol, LDL-cholesterol, VLDL-cholesterol and triglyceride did not show significant alteration at the end of the present study. In conclusion, the supplementation of HIV-positive patients with 600 mg/day of NAC did not bring additional benefits to those resulting from antiretroviral treatment.

INTRODUÇÃO As taxas de sobrevida do enxerto em transplante renal de doador falecido são menores que aquelas de doadores vivos. Acredita-se que metabólitos de estresse oxidativo sejam importantes mediadores de varias formas de lesão renal aguda, como insuficiência renal isquêmica, nefrotoxicidade por contraste e obstrução ureteral. O objetivo deste estudo é investigar os efeitos terapêuticos do antioxidante N-acetilcisteína na evolução precoce de receptores de transplante renal de doador falecido quanto à função do enxerto e ao estresse oxidativo. MÉTODO Entre abril de 2005 e junho de 2008, 74 receptores adultos de primeiro transplante renal de doador falecido foram distribuídos aleatoriamente em grupo tratado com N-acetilcisteína (n=38) ou controle (n=36) e avaliados prospectivamente por 90 dias. O grupo tratado com N-acetilcisteína (NAC) recebeu 600 mg por via oral, em duas tomadas diárias, por 7 dias, iniciado no dia do trasplante. A rejeição aguda comprovada por biópsia foi avaliada em até 30 dias de pós-operatório (PO). A função renal foi determinada por dosagem de creatinina sérica, cálculo do clearance de creatinina pela fórmula de Cockroft-Gault no 7º, 15º, 30º, 60º e 90º PO e comparação de número de dias em diálise ao longo do tempo após o transplante através de estimativa de Kaplan-Meier. A dosagem de substâncias reativas de ácido tiobarbitúrico (TBARS), que são marcadores de peroxidação lipídica e estresse oxidativo, foi determinada do 0-7º PO. A análise estatística foi realizada com auxílio do SPSS 16.0 e Qui-quadrado, teste exato de Fisher, teste t de Student, teste Mann-Whitney, ANOVA e teste log rank foram aplicados conforme indicado. RESULTADOS A rejeição aguda comprovada por biópsia foi menos freqüente, embora não significativa (p=0,203), entre os pacientes tratados com NAC (3/38 7,9% vs. 7/36 19,4%). O grupo tratado com NAC apresentou uma menor creatinina média durante o seguimento (p=0,026). A depuração de creatinina calculada foi maior para o grupo NAC (p=0,029). O número de dias em diálise de receptores ao longo do tempo após o transplante foi menor no grupo tratado com NAC (p=0,008). O estresse oxidativo foi significantemente reduzido (p<0,001) com NAC até o 7º PO. CONCLUSÃO A N-acetilcisteína melhorou a evolução precoce dos pacientes submetidos a transplante renal de doador falecido pela recuperação mais rápida e mantida da função renal, através da atenuação do estresse oxidativo / INTRODUCTION Deceased renal transplant graft survival rates are worse than those from living donors. Reactive oxygen metabolites are believed to be important mediators of various forms of acute kidney injury, such as ischaemic renal failure, radiocontrast nephrotoxicity and ureteral obstruction. The aim of this study is to investigate the therapeutic effects of the antioxidant N-acetylcysteine (NAC) on early outcomes of deceased renal transplant patients regarding graft function and oxidative stress. METHOD Between April 2005 and June 2008, 74 adult primary graft recipients of deceased renal donors were randomly assigned to treatment (NAC) (n=38) or control (n=36) group and prospectively evaluated for 90 days. Treatment group received N-acetylcysteine 600 mg bid po from 0 to 7th postoperative day (PO). Renal function was determined by serum creatinine, Cockroft-Gault estimated GFR (eGFR) at 7th, 15th, 30th, 60th and 90th PO and dialysis free Kaplan-Meier estimate curve. Serum levels of thiobarbituric acid reactive substances (TBARS), which are markers of lipid peroxidation and oxidative stress, were determined using the thiobarbituric acid assay from 0-7th PO. Statistical analysis was performed using SPSS 16.0 and Chi-square test, Fisher´s exact test, Student t test, Mann-Whitney test, ANOVA and log rank test were applied as indicated. RESULTS Biopsy confirmed acute rejection was less frequent, albeit not significant, with NAC (3/38 7.9% vs. 7/36 19.4%, p=0.203). NAC group presented a lower mean serum creatinine during follow-up (p=0.026). NAC group presented a higher mean eGFR (p=0.029). Kaplan-Meier estimate for dialysis free recipients presented less days of dialysis for the NAC group (p=0.008). Oxidative stress was significantly attenuated with NAC (p<0.001). CONCLUSION Our results suggest that N-acetylcysteine enhance deceased renal transplant outcomes by attenuating oxidative stress

Trabalhos experimentais demonstram o envolvimento de estresse oxidativo como mecanismo responsável pelas lesões cerebrais e hepáticas que acompanham a intoxicação pelo cloreto de metilmercúrio (CH3HgCI). A N-acetilcisteína (NAC) é capaz de ligar-se a metais e sequestrar radicais livres. O objetivo deste trabalho foi avaliar a influência da NAC sobre os níveis de mercúrio (Hg) e no estresse oxidativo induzido pelo metilmercúrio. Neste trabalho em ratos preconizamos a exposição oral a 20 mg de CH3HgCl/kg e intraperitoneal (ip) a 200 mg/kg de NAC, avaliados após 6, 12 e 24 horas e exposição oral a 0,5 mg de CH3HgCI/kg e doses de NAC (i.p.). Não houve aumento de TBARS hepático e cerebral após exposição aguda e sub-crônica. Dos antioxidantes apenas o ácido ascórbico mostrou-se diminuído após 12 horas da exposição. A NAC apresentou-se eficaz apenas na exposição sub-crônica com animais apresentando níveis de Hg reduzidos em fígado e cérebro / Experimental studies show oxidative stress to cause cerebral and hepatic lesions after methylmercury intoxication. N-acetylcysteine (NAC) is capable of binding to metals and scavenges free radicals. In this study we evaluated the influence of NAC on the levels of mercury (Hg) and on oxidative stress parameters after methylmercury chloride (CH3HgCI) exposure. A group of rats were treated by gavage with 20mg of CH3HgCl/kg body weight (b.w.) and 200mg/kg b.w. of NAC by intraperitoneal (ip) injection. These animals were killed after 6, 12 and 24hours. A second group received 0,5mg of CH3HgCl/kg b.w. by gavage during four weeks and five doses of NAC (200mg/kg b.w. ip) in the last week of exposure to CH3HgCI. There was no increase in hepatic and cerebral TBARS after the acute and subchronic exposure. Considering antioxidants, only ascorbic acid was reduced in liver after 12hours. NAC was effective decreasing mercury levels in brain, liver and kidney after subchronic exposure to CH3HgCI.

Trabalhos experimentais demonstram o envolvimento de estresse oxidativo como mecanismo responsável pelas lesões cerebrais e hepáticas que acompanham a intoxicação pelo cloreto de metilmercúrio (CH3HgCI). A N-acetilcisteína (NAC) é capaz de ligar-se a metais e sequestrar radicais livres. O objetivo deste trabalho foi avaliar a influência da NAC sobre os níveis de mercúrio (Hg) e no estresse oxidativo induzido pelo metilmercúrio. Neste trabalho em ratos preconizamos a exposição oral a 20 mg de CH3HgCl/kg e intraperitoneal (ip) a 200 mg/kg de NAC, avaliados após 6, 12 e 24 horas e exposição oral a 0,5 mg de CH3HgCI/kg e doses de NAC (i.p.). Não houve aumento de TBARS hepático e cerebral após exposição aguda e sub-crônica. Dos antioxidantes apenas o ácido ascórbico mostrou-se diminuído após 12 horas da exposição. A NAC apresentou-se eficaz apenas na exposição sub-crônica com animais apresentando níveis de Hg reduzidos em fígado e cérebro / Experimental studies show oxidative stress to cause cerebral and hepatic lesions after methylmercury intoxication. N-acetylcysteine (NAC) is capable of binding to metals and scavenges free radicals. In this study we evaluated the influence of NAC on the levels of mercury (Hg) and on oxidative stress parameters after methylmercury chloride (CH3HgCI) exposure. A group of rats were treated by gavage with 20mg of CH3HgCl/kg body weight (b.w.) and 200mg/kg b.w. of NAC by intraperitoneal (ip) injection. These animals were killed after 6, 12 and 24hours. A second group received 0,5mg of CH3HgCl/kg b.w. by gavage during four weeks and five doses of NAC (200mg/kg b.w. ip) in the last week of exposure to CH3HgCI. There was no increase in hepatic and cerebral TBARS after the acute and subchronic exposure. Considering antioxidants, only ascorbic acid was reduced in liver after 12hours. NAC was effective decreasing mercury levels in brain, liver and kidney after subchronic exposure to CH3HgCI.

Rationale: In the breast cancer setting, anti-cancer therapies, including Doxorubicin (DOX) and Trastuzumab (TRZ), are associated with an increased risk of cardiotoxicity. There is a need to develop prophylactic cardioprotective agents to mitigate the cardiotoxic side effects of these common anti-cancer drugs. Objective: To investigate whether the anti-oxidant, N-acetylcysteine amide (NACA), can attenuate the drug-induced heart failure caused by DOX+TRZ in a murine model. Methods: A total of 100 female mice received one of the following drug regimens: i) saline; ii) NACA; iii) DOX; iv) TRZ; v) DOX+TRZ; vi) NACA+DOX; vii) NACA+TRZ; and viii) NACA+DOX+TRZ. Serial echocardiography was performed over a 10-day study period, after which the mice were euthanized for histological and biochemical analyses. Results: In mice receiving DOX, left ventricular ejection fraction (LVEF) decreased from 73±4% to 43±2% at day 10. In mice receiving DOX+TRZ, LVEF decreased from 72±3% to 32±2% at day 10. Prophylactic administration of NACA to mice receiving DOX or DOX+TRZ was cardio-protective with an LVEF of 62±3% and 55±3% at day 10, respectively. Histological and biochemical analyses demonstrated loss of cellular integrity, increased oxidative stress (OS), and increased cardiac apoptosis in mice treated with DOX+TRZ which was attenuated by the prophylactic administration of NACA. Conclusion: NACA attenuates the cardiotoxic side effects of DOX+TRZ in a murine model of chemotherapy induced cardiac dysfunction by decreasing OS and apoptosis. / October 2015

Cystic fibrosis (CF) is an inborn, hereditary disease, due to mutations in the gene for a cAMP-activated chloride (Cl-) channel, the cystic fibrosis transmembrane conductance regulator (CFTR). As a result of impaired ion and water transport,the airway mucus is abnormally viscous, which leads to bacterial colonization.Recurrent infections and inflammation result in obstructive pulmonary disease.Similar changes in the pancreas lead to pancreatic insufficiency.Several compounds have been tested to improve transepithelial ion transport in CF patients, either via activation of the mutant CFTR, or via stimulation of alternative chloride channels. The main purpose of this thesis was to find substances that might correct the defective ion transport in epithelial cells in CFand could be useful for the pharmacological treatment of CF patients. Long-term treatment with the macrolide antibiotic azithromycin (AZM)improved clinical parameters and lung function in CF patients and increased Cl- transport in CF bronchial epithelial cells (CFBE) (Paper I); although mRNA expression of the CFTR gene remained unchanged.In contrast, pre-exposure to the mucolytic antioxidant N-acetylcysteine (NAC) increased CFTR protein expression and was associated with increased Cl- efflux from CFBE cells (Paper II). Clinical trials of this substance might be warranted. Duramycin has been the subject of clinical trials that finished in June2009. Up till now, no results from this study are available. The effect of this substance on Cl- efflux from three CF and three non-CF cell lines (Paper III) was disappointing. An effect was found only in CFBE cells, the effect was minimal, occurred in a narrow concentration range, and was not associated with an increase in the intracellular calcium concentration [Ca2+]i. The fact that NO-donors stimulated Cl- efflux from CFBE cells (but did notchange [Ca2+]i) after several hours of preincubation suggests that these substances may be a potentially interesting group of compounds for the treatment of CF (Paper IV). A model for the effect of NO-donors on Cl- efflux is presented. / Cystisk fibros (CF) är en medfödd, ärftlig, sjukdom, som förorsakas av en mutation i en gen som innehåller koden för en kloridkanal som aktiveras av cykliskt AMP (cystic fibrosis transmembrane conductance regulator, CFTR). Som en följd av otillräcklig transport av joner och vatten är slemmet i luftvägarna onormalt segt, vilket leder till att det koloniseras av bakterier. Upprepade infektioneroch inflammation av luftvägarna leder slutligen till obstruktiv lungsjukdom.Liknande förändringar i bukspottkörteln leder till att också detta organ inte fungerar. Flera kemiska ämnen har testats för sin förmåga att förbättra jontransporten över epitelet hos CF-patienter. Detta skulle kunna göras antingen genom aktivering av det muterade CFTR-proteinet, eller genom stimulering av alternativa kloridkanaler. Huvudsyftet med den forskning som beskrivs i denna avhandling var att hitta kemiska substanser som skulle kunna korrigera den defekta jontransporten i epitelceller hos CF-patienter, och därför vara nyttiga för behandlingen av patienterna. Behandling under längre tid med azithromycin (AZM), ett makrolidantibiotikum,förbättrade CF-patienternas kliniska status och lungfunktion,samt ökade kloridutflödet från CF bronkialepitelceller (CFBE-celler) (Arbete I).Däremot ändrades inte uttrycket av mRNA för CFTR-genen. I kontrast till detta ökade uttrycket av CFTR-proteinet om CFBE-cellerna utsattes för den slemlösande anti-oxidanten N-acetylcystein (NAC), vilket ledde till ökat kloridutflöde från denna cellinje (Arbete II). Det vore rimligt att utföra kliniska prövningar av detta ämne. Duramycin har testats i kliniska prov som slutade i juni 2009, men några resultatfrån dessa prov har inte offentliggjorts än. Effekten av detta ämne på kloridutflödet från tre CF-cellinjer och tre icke-CF cellinjer (Arbete III) var en besvikelse. Duramycin hade endast effekt på CFBE-celler, effekten var mycket liten, förekom endast i ett litet koncentrationsområde av duramycin, och var inte kopplad till en ökning av den intracellulära kalciumkoncentrationen [Ca2+]i. Att ämnen som avger kväveoxid (NO) stimulerade kloridutflödet från CFceller (men inte påverkade [Ca2+]i) efter några timmar, visar att denna grupp av ämnen kan vara potentiellt intressant för behandlingen av CF (arbete IV). En modell för effekten av NO på kloridtransporten i CF-celler presenteras.

Thesis (Ph.D.)--University of Alabama at Birmingham, 2007. / Title from PDF title page (viewed on Sept. 15, 2009). Includes bibliographical references.