The aim of this study was to determine histamine content in the brain and the effect of histamine receptor antagonists on behavior of adult rats lesioned as neonates with the serotonin (5-HT) neurotoxin 5,7-dihydroxytryptamine (5,7-DHT). At 3 days after birth Wistar rats were pretreated with desipramine (20 mg/kg ip) before bilateral icv administration of 5,7-DHT (37.5 μg base on each side) or saline-ascorbic (0.1%) vehicle (control). At 10 week levels of 5-HT and its metabolite 5-hydroxyindole acetic acid (5-HIAA) were determined in frontal cortex, striatum, and hippocampus by an HPLC/ED technique. In the hypothalamus, frontal cortex, hippocampus and medulla oblongata, the level of histamine was analyzed by an immunoenzymatic method. Behavioral observations (locomotion, exploratory-, oral-, and stereotyped activity) were performed, and effects of DA receptor agonists (SKF 38393, apomorphine) and histamine receptor antagonists S(+)chlorpheniramine (H1), cimetidine (H2), and thioperamide (H3) were determined. We confirmed that 5,7-DHT profoundly reduced contents of 5-HT and 5-HIAA in the brain in adulthood. Histamine content was also reduced in all examined brain regions. Moreover, in 5,7-DHT-lesioned rats the locomotor and oral activity responses to thioperamide were altered, and apomorphineinduced stereotype was intensified. From the above, we conclude that an intact central serotoninergic system modulates histamine H3 receptor antagonist effects on the dopaminergic neurons in rats.

Osteoarthritis (OA) is the most prevalent arthritis in the world with increasing numbers of people expected to acquire the disease as the population ages. Therapies commonly used to manage the disease have limited efficacy and some carry significant risks. Current data suggest that the anti-inflammatory cytokine IL-1 receptor antagonist (IL-1Ra) can alter the inflammatory response and cartilage erosion present in OA. Intra-articular gene expression of IL-1Ra has shown promising results in animal models to provide symptomatic improvement and minimize osteoarthritic changes. Orthogen AG (Dusseldorf, Germany) has developed a method to produce an autologous conditioned serum (ACS) rich in IL-1Ra marketed as Orthokine®. Study participants treated with ACS have improved pain and function; however, these results are preliminary and need confirmation. If ongoing trials prove that ACS can retard cartilage degeneration and reduce inflammation, the management of OA would be dramatically altered, perhaps providing a mechanism to prevent the disease or at least its progression.

The overall aim of this thesis was to establish strategies to minimize secondary damage to the injured spinal cord. Secondary damage that follows spinal cord injury (SCI) involves inflammatory and excitotoxic pathways. Regulation of these pathways using immunomodulatory and neuroprotective substances potentially protects the injured spinal cord from further damage. We also developed and studied resorbable biomaterials to be used as carriers for potential neuroprotectants to the injured spinal cord. We used transversal spinal cord slice cultures (SCSCs) derived from postnatal mice as a model. SCSCs were maintained on different biomaterials and were studied after treatment with immunomodulatory and/or neurotrophic factors. They were further excitotoxically injured and subsequently treated with interleukin-1 receptor antagonist (IL1RA) or by neural crest stem cell (NCSC)-transplantation. The results show that biocompatible and resorbable hydrogels based on hyaluronic acid (HA) preserved neurons in SCSCs to a much higher extent than a conventional collagen-based biomaterial or standard polyethylene terephthalate (PET) membrane inserts. Glial activation was limited in the cultures maintained on HA-based hydrogel. The anti-inflammatory factor IL1RA protected SCSCs from degenerative mechanisms that occur during in vitro incubation, and IL1RA also protected SCSCs from excitotoxic injury induced by N-Methyl-d-Aspartate (NMDA). IL1RA specifically protected neurons that resided in the ventral horn, while other neuronal populations such as dorsal horn neurons and Renshaw cells did not respond to treatment. Finally, transplantation of NCSCs onto excitotoxically injured SCSCs protected from neuronal loss, apoptosis and glial activation, while NCSCs remained undifferentiated. The results presented in this thesis indicate that carriers based on HA seem to be more suitable than conventional collagen-based biomaterials since they enhance neuronal survival per se. The observed neuroprotection is likely due to biomechanical properties of HA. IL1RA protects SCSCs from spontaneous degeneration and from NMDA-induced injury, suggesting that excitotoxic mechanisms can be modulated through anti-inflammatory pathways. Different neuronal populations are affected by IL1RA to various degrees, suggesting that a combination of different neuroprotectants should be used in treatment strategies after SCI. Finally, NCSCs seem to protect SCSCs from excitotoxic injury through paracrine actions, since they remain undifferentiated and do not migrate into the tissue during in vitro incubation. It seems that combinations of neuroprotectants and carrier substances should be considered rather than one single strategy when designing future treatments for SCI. Incorporation of neuroprotectants such as IL1RA combined with stem cells in injectable biocompatible carriers based on HA is the final goal of our group in the treatment of SCI.

Nicotine is a psychomotor stimulant with ‘reinforcement enhancing’ effects — the actions of nicotine in the brain increase responding for non-nicotine rewards. We hypothesized that this latter effect of nicotine depends on increased incentive properties of anticipatory cues; consistent with this hypothesis, multiple laboratories have reported that nicotine increases sign tracking, i.e. approach to a conditioned stimulus (CS), in Pavlovian conditioned-approach tasks. Incentive motivation and sign tracking are mediated by mesolimbic dopamine (DA) transmission and nicotine facilitates mesolimbic DA release. Therefore, we hypothesized that the incentive-promoting effects of nicotine would be impaired by DA antagonists. To test this hypothesis, separate groups of rats were injected with nicotine (0.4 mg/kg base) or saline prior to Pavlovian conditioning sessions in which a CS (30 s illumination of a light or presentation of a lever) was immediately followed by a sweet reward delivered in an adjacent location. Both saline and nicotine pretreated rats exhibited similar levels of conditioned approach to the reward location (goal tracking), but nicotine pretreatment significantly increased approach to the CS (sign tracking), regardless of type (lever or light). The DAD1 antagonist SCH-23390 and the DAD2/3antagonist eticlopride reduced conditioned approach in all rats, but specifically reduced goal tracking in the saline pretreated rats and sign tracking in the nicotine pretreated rats. The non-selective DA antagonist flupenthixol reduced sign-tracking in nicotine rats at all doses tested; however, only the highest dose of flupenthixol reduced goal tracking in both nicotine and saline groups. The reductions in conditioned approach behavior, especially those by SCH-23390, were dissociated from simple motor suppressant effects of the antagonists. These experiments are the first to investigate the effects of dopaminergic drugs on the facilitation of sign-tracking engendered by nicotine and they implicate dopaminergic systems both in conditioned approach as well as the incentive-promoting effects of nicotine.

Thesis (Ph.D. in Pharmaceutical Sciences) -- University of Colorado Denver, 2007. / Typescript. Includes bibliographical references (leaves 133-143). Online version available via ProQuest Digital Dissertations.

A lesão de isquemia e reperfusão pulmonar (LIRI) é a principal causa de disfunção precoce do enxerto após o transplante pulmonar. Diferentes substâncias têm sido utilizadas na tentativa de proteger o pulmão na fase inicial pós-transplante e melhorar o desempenho do enxerto com pouco resultado tanto a curto quanto em longo prazo. O peptídeo liberador gastrina (GRP) está envolvido na indução de respostas imunes inatas adaptativas por induzir a quimiotaxia de mastócitos, migração de macrófagos e proliferação de células T e fibroblastos. Este agente foi capaz de proteger o dano tecidual em outros modelos experimentais de inflamação, incluindo sepsis pós-isquemia e perfuração de ceco, artrite e colite induzidos por drogas. O efeito protetor foi atribuído ao bloqueio na liberação de citocinas pró-inflamatórias, como da interleucina -1 beta (IL-1G) e TNF- alfa (TNF-H), e inibição de migração de mononucleares. Nesta tese o efeito protetor do antagonista do receptor de peptídeo liberador de gastrina (GRPR), o RC-3095 (RC) endovenosamente administrado antes e depois da reperfusão foi estudado em modelo animal de LIRI. Vinte ratos Wistar foram randomizados em quatro grupos: (SHAM), Isquemia-reperfusão (IR), administração de RC Pré-IR (RC-Pré) e RC Pós-IR (RC-Pós). Após a reperfusão, os animais foram observados por 120 minutos. Foi realizada a análise histológica, com verificação de escala de lesão pulmonar, e imunohistoquímica para Caspase clivada - 9 e oxido nítrico sintetase endotelial (eNOS). Expressão de IL-1G e TNF-H foram quantificadas por Enzime-Linked Immunosorbent Assay (ELISA). Uma redução significativa na pressão arterial média foi observada nos grupos IR e RC - Pré quando comparado com seus valores antes da reperfusão (p < 0.001). No final do experimento o grupo RC-Pós apresentou uma redução significativa na pressão arterial de oxigênio em relação ao início (p=0.005). Observou-se maior expressão de Caspase - 9 clivada no grupo RC-Pós (p>0.013), quando comparado aos demais grupos. Não houve diferença significativa na captação da eNOS entre os grupos (p=0.206). Os grupos RC - Pré e Pós mostraram discreta redução, não atingindo significância estatística, da IL-1G (p=0.159) e TNF- H (p= 0.260), quando comparado com o grupo IR. Não houve diferença estatística entre as médias dos escores histológicos entre os diferentes grupos. e SHAM. Notavelmente, quando administrado após reperfusão parece potencializar dano celular estimulando a apoptose. Concluindo, a utilização do antagonista do peptídeo liberador de gastrina, RC-3095, não produziu efeito protetor significativo na resposta inflamatória em pulmões de ratos. Estudos adicionais devem ser implementados para confirmar estes achados. / Lung ischemia reperfusion injury (LIRI) is the main cause of early graft dysfunction and death after lung transplantation. Several methods and substances have been used as an attempt to protect the lung during the early phase after transplantation and improve graft performance at short and long term with limited results. The selective gastrin-releasing peptide receptor (GRPR) antagonist RC-3095 (RC) was shown to protect from damage in various models of inflammation, including sepsis due to cecal ischemia and perforation, drug-induced arthritis and colitis, probably due to the inhibition in the release of proinflammatory cytokines, such as interleukin-1-beta and TNFalpha, as well as interference with mononuclear migration. In this thesis, the protective effect of the selective gastrin-releasing peptide receptor (GRPR) antagonist RC-3095, administrated intravenous before and after reperfusion was studied in an animal model of LIRI. A total of 20 Wistar rats were randomized in four groups: (SHAM), Ischemia-reperfusion (IR), RC Pre-IR (RCPre) and the RC Post-IR (RC-Post) .The IR groups were submitted to a model of ischemia/reperfusion by clamping of the left pulmonary hilum for 45 minutes followed by reperfusion for 120 minutes. We recorded the hemodynamic parameters, blood gas analysis and histology. We analyzed Cleaved Caspase- 9 and endothelial nitric oxide synthase (eNOS) by immunohistochemistry. Expression of IL-1G and TNF-H was evaluated by Enzyme-Linked Immunosorbent Assay (ELISA). We observed that the final mean arterial pressure significantly decreased in IR and RC Pre-IR compared to their values before reperfusion (p < 0.001).The RC-Post group showed significant decrease of partial pressure of arterial oxygen at the end of the observation compared to baseline (p=0.005). Caspase-9 activity was significantly higher in the RC-Post- IR as compared to the other groups (p < 0.013). No significant differences were observed of eNOS activity among the groups. The groups RC Pre-IR e RC Post-IR did not show a significant decrease of IL-1G (p=0.159) and TNF-H (p= 0.260), as compared to IR. The histological score showed no significant differences among the groups. Notably, its use after reperfusion seems to potentiate cell damage, stimulating apoptosis In conclusion, RC3095, a selective GRPR antagonist failed to demonstrate a significant protective effect in our LIRI model in male Wistar rats. Further studies to address this question are warranted.

A lesão de isquemia e reperfusão pulmonar (LIRI) é a principal causa de disfunção precoce do enxerto após o transplante pulmonar. Diferentes substâncias têm sido utilizadas na tentativa de proteger o pulmão na fase inicial pós-transplante e melhorar o desempenho do enxerto com pouco resultado tanto a curto quanto em longo prazo. O peptídeo liberador gastrina (GRP) está envolvido na indução de respostas imunes inatas adaptativas por induzir a quimiotaxia de mastócitos, migração de macrófagos e proliferação de células T e fibroblastos. Este agente foi capaz de proteger o dano tecidual em outros modelos experimentais de inflamação, incluindo sepsis pós-isquemia e perfuração de ceco, artrite e colite induzidos por drogas. O efeito protetor foi atribuído ao bloqueio na liberação de citocinas pró-inflamatórias, como da interleucina -1 beta (IL-1G) e TNF- alfa (TNF-H), e inibição de migração de mononucleares. Nesta tese o efeito protetor do antagonista do receptor de peptídeo liberador de gastrina (GRPR), o RC-3095 (RC) endovenosamente administrado antes e depois da reperfusão foi estudado em modelo animal de LIRI. Vinte ratos Wistar foram randomizados em quatro grupos: (SHAM), Isquemia-reperfusão (IR), administração de RC Pré-IR (RC-Pré) e RC Pós-IR (RC-Pós). Após a reperfusão, os animais foram observados por 120 minutos. Foi realizada a análise histológica, com verificação de escala de lesão pulmonar, e imunohistoquímica para Caspase clivada - 9 e oxido nítrico sintetase endotelial (eNOS). Expressão de IL-1G e TNF-H foram quantificadas por Enzime-Linked Immunosorbent Assay (ELISA). Uma redução significativa na pressão arterial média foi observada nos grupos IR e RC - Pré quando comparado com seus valores antes da reperfusão (p < 0.001). No final do experimento o grupo RC-Pós apresentou uma redução significativa na pressão arterial de oxigênio em relação ao início (p=0.005). Observou-se maior expressão de Caspase - 9 clivada no grupo RC-Pós (p>0.013), quando comparado aos demais grupos. Não houve diferença significativa na captação da eNOS entre os grupos (p=0.206). Os grupos RC - Pré e Pós mostraram discreta redução, não atingindo significância estatística, da IL-1G (p=0.159) e TNF- H (p= 0.260), quando comparado com o grupo IR. Não houve diferença estatística entre as médias dos escores histológicos entre os diferentes grupos. e SHAM. Notavelmente, quando administrado após reperfusão parece potencializar dano celular estimulando a apoptose. Concluindo, a utilização do antagonista do peptídeo liberador de gastrina, RC-3095, não produziu efeito protetor significativo na resposta inflamatória em pulmões de ratos. Estudos adicionais devem ser implementados para confirmar estes achados. / Lung ischemia reperfusion injury (LIRI) is the main cause of early graft dysfunction and death after lung transplantation. Several methods and substances have been used as an attempt to protect the lung during the early phase after transplantation and improve graft performance at short and long term with limited results. The selective gastrin-releasing peptide receptor (GRPR) antagonist RC-3095 (RC) was shown to protect from damage in various models of inflammation, including sepsis due to cecal ischemia and perforation, drug-induced arthritis and colitis, probably due to the inhibition in the release of proinflammatory cytokines, such as interleukin-1-beta and TNFalpha, as well as interference with mononuclear migration. In this thesis, the protective effect of the selective gastrin-releasing peptide receptor (GRPR) antagonist RC-3095, administrated intravenous before and after reperfusion was studied in an animal model of LIRI. A total of 20 Wistar rats were randomized in four groups: (SHAM), Ischemia-reperfusion (IR), RC Pre-IR (RCPre) and the RC Post-IR (RC-Post) .The IR groups were submitted to a model of ischemia/reperfusion by clamping of the left pulmonary hilum for 45 minutes followed by reperfusion for 120 minutes. We recorded the hemodynamic parameters, blood gas analysis and histology. We analyzed Cleaved Caspase- 9 and endothelial nitric oxide synthase (eNOS) by immunohistochemistry. Expression of IL-1G and TNF-H was evaluated by Enzyme-Linked Immunosorbent Assay (ELISA). We observed that the final mean arterial pressure significantly decreased in IR and RC Pre-IR compared to their values before reperfusion (p < 0.001).The RC-Post group showed significant decrease of partial pressure of arterial oxygen at the end of the observation compared to baseline (p=0.005). Caspase-9 activity was significantly higher in the RC-Post- IR as compared to the other groups (p < 0.013). No significant differences were observed of eNOS activity among the groups. The groups RC Pre-IR e RC Post-IR did not show a significant decrease of IL-1G (p=0.159) and TNF-H (p= 0.260), as compared to IR. The histological score showed no significant differences among the groups. Notably, its use after reperfusion seems to potentiate cell damage, stimulating apoptosis In conclusion, RC3095, a selective GRPR antagonist failed to demonstrate a significant protective effect in our LIRI model in male Wistar rats. Further studies to address this question are warranted.

A lesão de isquemia e reperfusão pulmonar (LIRI) é a principal causa de disfunção precoce do enxerto após o transplante pulmonar. Diferentes substâncias têm sido utilizadas na tentativa de proteger o pulmão na fase inicial pós-transplante e melhorar o desempenho do enxerto com pouco resultado tanto a curto quanto em longo prazo. O peptídeo liberador gastrina (GRP) está envolvido na indução de respostas imunes inatas adaptativas por induzir a quimiotaxia de mastócitos, migração de macrófagos e proliferação de células T e fibroblastos. Este agente foi capaz de proteger o dano tecidual em outros modelos experimentais de inflamação, incluindo sepsis pós-isquemia e perfuração de ceco, artrite e colite induzidos por drogas. O efeito protetor foi atribuído ao bloqueio na liberação de citocinas pró-inflamatórias, como da interleucina -1 beta (IL-1G) e TNF- alfa (TNF-H), e inibição de migração de mononucleares. Nesta tese o efeito protetor do antagonista do receptor de peptídeo liberador de gastrina (GRPR), o RC-3095 (RC) endovenosamente administrado antes e depois da reperfusão foi estudado em modelo animal de LIRI. Vinte ratos Wistar foram randomizados em quatro grupos: (SHAM), Isquemia-reperfusão (IR), administração de RC Pré-IR (RC-Pré) e RC Pós-IR (RC-Pós). Após a reperfusão, os animais foram observados por 120 minutos. Foi realizada a análise histológica, com verificação de escala de lesão pulmonar, e imunohistoquímica para Caspase clivada - 9 e oxido nítrico sintetase endotelial (eNOS). Expressão de IL-1G e TNF-H foram quantificadas por Enzime-Linked Immunosorbent Assay (ELISA). Uma redução significativa na pressão arterial média foi observada nos grupos IR e RC - Pré quando comparado com seus valores antes da reperfusão (p < 0.001). No final do experimento o grupo RC-Pós apresentou uma redução significativa na pressão arterial de oxigênio em relação ao início (p=0.005). Observou-se maior expressão de Caspase - 9 clivada no grupo RC-Pós (p>0.013), quando comparado aos demais grupos. Não houve diferença significativa na captação da eNOS entre os grupos (p=0.206). Os grupos RC - Pré e Pós mostraram discreta redução, não atingindo significância estatística, da IL-1G (p=0.159) e TNF- H (p= 0.260), quando comparado com o grupo IR. Não houve diferença estatística entre as médias dos escores histológicos entre os diferentes grupos. e SHAM. Notavelmente, quando administrado após reperfusão parece potencializar dano celular estimulando a apoptose. Concluindo, a utilização do antagonista do peptídeo liberador de gastrina, RC-3095, não produziu efeito protetor significativo na resposta inflamatória em pulmões de ratos. Estudos adicionais devem ser implementados para confirmar estes achados. / Lung ischemia reperfusion injury (LIRI) is the main cause of early graft dysfunction and death after lung transplantation. Several methods and substances have been used as an attempt to protect the lung during the early phase after transplantation and improve graft performance at short and long term with limited results. The selective gastrin-releasing peptide receptor (GRPR) antagonist RC-3095 (RC) was shown to protect from damage in various models of inflammation, including sepsis due to cecal ischemia and perforation, drug-induced arthritis and colitis, probably due to the inhibition in the release of proinflammatory cytokines, such as interleukin-1-beta and TNFalpha, as well as interference with mononuclear migration. In this thesis, the protective effect of the selective gastrin-releasing peptide receptor (GRPR) antagonist RC-3095, administrated intravenous before and after reperfusion was studied in an animal model of LIRI. A total of 20 Wistar rats were randomized in four groups: (SHAM), Ischemia-reperfusion (IR), RC Pre-IR (RCPre) and the RC Post-IR (RC-Post) .The IR groups were submitted to a model of ischemia/reperfusion by clamping of the left pulmonary hilum for 45 minutes followed by reperfusion for 120 minutes. We recorded the hemodynamic parameters, blood gas analysis and histology. We analyzed Cleaved Caspase- 9 and endothelial nitric oxide synthase (eNOS) by immunohistochemistry. Expression of IL-1G and TNF-H was evaluated by Enzyme-Linked Immunosorbent Assay (ELISA). We observed that the final mean arterial pressure significantly decreased in IR and RC Pre-IR compared to their values before reperfusion (p < 0.001).The RC-Post group showed significant decrease of partial pressure of arterial oxygen at the end of the observation compared to baseline (p=0.005). Caspase-9 activity was significantly higher in the RC-Post- IR as compared to the other groups (p < 0.013). No significant differences were observed of eNOS activity among the groups. The groups RC Pre-IR e RC Post-IR did not show a significant decrease of IL-1G (p=0.159) and TNF-H (p= 0.260), as compared to IR. The histological score showed no significant differences among the groups. Notably, its use after reperfusion seems to potentiate cell damage, stimulating apoptosis In conclusion, RC3095, a selective GRPR antagonist failed to demonstrate a significant protective effect in our LIRI model in male Wistar rats. Further studies to address this question are warranted.

Il est bien établi que la vasopressine (AVP) est élevée dans le diabète tant humain qu'expérimental. Chez l'homme, plusieurs études récentes ont montré une association entre la copeptine (biomarqueur de la sécrétion d'AVP), et la survenue d'un diabète ou d'une hyperglycémie, le syndrome métabolique et l'obésité. Dans l'équipe, nous avons montré une association inverse entre la consommation d'eau (diminue la sécrétion AVP) et le risque de survenue d'hyperglycémie dans la cohorte D.E.S.I.R. Le but de mon projet de thèse a été de déterminer le rôle de l'AVP et de la prise hydrique dans l'homéostasie glucidique chez le rat sain et dans un modèle de rat présentant un syndrome métabolique. L'administration aigüe ou chronique d'AVP augmente la glycémie et cet effet est réversé par un antagoniste des récepteurs V1a. L'activation des récepteurs V1b ne modifie pas l'insulino-sécrétion mais stimule en permanence et de façon modérée la glucagonémie. Ces effets ont été observés sur deux souches différentes de rats sains. Chez le rat Zucker obèse, l'AVP aggrave l'hyperinsulinémie à jeun et l'intolérance au glucose alors que le régime hydraté ne modifie pas la tolérance au glucose mais réduit très fortement la stéatose hépatique ainsi que le contenu hépatique en cholestérol et triglycérides et l'expression des gènes impliqués dans la lipogenèse. En conclusion, ces travaux montrent pour la première fois, que l'AVP dégrade à long terme la tolérance au glucose ; a contrario, un régime fortement hydraté est protecteur. Ces résultats, en accord avec nos données épidémiologiques, démontrent un lien de causalité entre vasopressine/hydratation et désordre du métabolisme glucidique. / It is well established that vasopressin (AVP) level is high in both human and experimental diabetes. In humans, several recent studies have shown an association between copeptin (biomarker of AVP secretion) and the occurrence of diabetes mellitus or hyperglycemia, metabolic syndrome and obesity. Our team has shown a reverse association between water consumption (decrease AVP secretion) and the risk of hyperglycemia in the general population (D.E.S.I.R cohort). The aim of my thesis was to determine the role of AVP and fluid intake in glucose homeostasis in healthy rats and in a rat model of metabolic syndrome. AVP, administered acutely or chronically in healthy rats, increases glycaemia and this effect is reversed by a V1a receptor antagonist. V1b receptor activation does not influence insulin secretion but stimulates moderately basal glucagon production by the pancreas. These effects were observed in two different healthy strains of rats. In obese Zucker rats, a high AVP level worsens fasting hyperinsulinaemia and glucose intolerance whereas hydration does not affect glucose tolerance but drastically reduces hepatic steatosis, the content of cholesterol and triglycerides in liver and expression of genes involved in hepatic lipogenesis. In conclusion, these studies show for the first time, that AVP aggravates glucose tolerance whereas a highly hydrated diet is protective. These results, in agreement with our epidemiological data, demonstrate a causal link between vasopressin and/or hydration and glucose metabolism disorders.

No description available.