Tratamentos alternativos para a depressão humana vêm sendo realizados pela homeopatia e fitoterapia, por meio do Hypericum perforatum (Hp), dinamizado ou extrato, respectivamente. Experimentalmente, o desamparo aprendido é proposto como modelo animal de depressão, o que permite seu uso para o teste de substâncias potencialmente antidepressivas. Assim, foram realizados dois experimentos para verificar se o Hp em preparação homeopática e fitoterápica impediriam o desamparo aprendido em animais. No Experimento 1, foram utilizados 96 ratos Wistar, machos, distribuídos em doze grupos (n=8), expostos às fases choque e teste, separadas por 24h. Os grupos foram manipulados em tríades, tratados com choques (60, 1,0 mA, VT 60s, 10s máx.) controláveis (C), incontroláveis (I) ou nenhum choque (N). Após esse tratamento, as tríades receberam 5 gotas, v.o. de: Hp 30CH, Hp 200CH e 0CH (veículo - solução hidroalcóolica a 5%), três vezes, com intervalo de 0, 19 e 23h após o término da fase choque. A quarta tríade não recebeu substância (sd) e foi utilizada para comparação em ambos os experimentos. No teste, todos os sujeitos foram submetidos a uma contingência de fuga, com 30 choques, semelhantes aos anteriores, em uma shuttlebox. No Experimento 2, foram utilizados 72 ratos com as mesmas características, distribuídos em nove grupos (n=8). Os equipamentos foram os mesmos e o procedimento foi semelhante ao do Experimento 1, com diferença apenas na fase de administração da droga, sendo que cada tríade recebeu extrato de Hp i.p., 1ml/kg, nas doses: 0mg/kg (veículo - solução hidroalcóolica a 5%), 15 mg/kg e 30 mg/kg, 22 horas após o término da fase choque. Os resultados mostraram que apenas o Grupo I da Tríade sd apresentou desamparo aprendido. No Experimento 1, as substâncias não produziram efeito sobre os grupos N e C, enquanto os grupos I tiveram redução das latências, sendo o efeito mais significativo com Hp 200CH. O tratamento 0CH produziu uma pequena redução das latências gerais, embora não suficiente para abolir o desamparo. Os resultados do Experimento 2 mostraram que os grupos N e C não sofreram efeito das substâncias, enquanto os grupos I tiveram redução da suas latências, sendo o efeito maior com Hp 0 mg/kg. Esses resultados sugerem que o veículo não era farmacologicamente inerte, comprometendo os demais resultados do Hp. Conclui-se que os efeitos de tratamentos da homeopatia e fitoterapia precisam ser mais investigados para que uma afirmação da sua eficácia tenha mais confiabilidade. / Alternative treatments for the human depression have been conducted in the homeopathy and phytoterapy, through Hypericum perforatum (Hp), dynamized or extract, respectively. Experimentally, learned helplessness is proposed as an animal model of depression, which permits its use to test the effects of potential antidepressants. Two experiments were conducted to investigate whether Hp, either in homeophatic and or in phytotherapic preparation, can prevent the occurrence of learned helplessness in animals. In the Experiment 1, 96 male Wistar rats were divided into 12 groups (n=8) exposed to treatment and test phases, separated by 24 hours. Groups were divided into triads exposed to controllable shocks (C), uncontrollable shocks (I) or no shocks (N). After that, Hp was administered orally (five drops) to each triad in one of three dynamizations – 30CH, 200CH and 0CH (vehicle - hydroalcoholic solution 5%) – three times: 0, 19, and 23 hours after treatment with shocks. The fourth triad didn’t receive drug (sd) and it was used in both experiments. In the test phase, all the animals were exposed to an escape contingency in a shuttlebox. In the Experiment 2, 72 rats were divided into 9 groups (n=8). Equipments were the same and procedure was similar to Experiment 1, with the exception of drug administration. Extract of Hp was administered, i.p., 1 ml/kg, in one of three concentrations for each triad – 0 mg/kg (vehicle – hydroalcoholic solution 5%), 15 mg/kg and 30 mg/kg - 22 hours after treatment with shocks. Results showed that, among the groups that were not administered pharmacological treatment, only Group I did not learn to escape, an indication of learned helplessness. In Experiment 1, among the groups that were administered Hp in homeopathic preparation, groups N and C were not affected, while response latencies for groups I decreased, with a stronger effect with 200CH. Treatment with 0CH caused a small reduction of general latencies, although it wasn’t suficient to prevent helplessness. In Experiment 2, results showed that Hp in phytotherapic administration didn’t affect groups N and C, while the latencies of Group I were reduced, with a stronger effect with Hp 0mg/kg. These data suggest that the vehicle wasn’t inert pharmacologically, which casts doubt on the results that involved Hp. In conclusion, more studies will be necessary to attest the efficacy of homeopathic and phytotherapic treatment.

Diversas evidências indicam que o núcleo dorsal da rafe (NDR), principal fonte de inervação serotonérgica para estruturas límbicas, é uma estrutura heterogênea composta por populações de neurônios serotonérgicos anatômica e funcionalmente distintas, as quais têm sido diferentemente implicadas na fisiopatologia dos transtornos de ansiedade, como o transtorno do pânico. Fármacos antidepressivos são a primeira escolha para o tratamento de tais transtornos e o atraso para a manifestação dos efeitos terapêuticos desses fármacos tem sido, consistentemente, associado a alterações na neurotransmissão serotonérgica. Entretanto, ainda é desconhecido se estas alterações podem ser heterogêneas entre as diferentes sub-regiões do NDR e é este o foco de investigação do presente estudo. Inicialmente, foi investigado o perfil de ativação neuronal das diferentes sub-regiões do NDR, através da avaliação da expressão de proteína Fos, em ratos submetidos à tarefa de fuga no modelo do labirinto em T elevado, após administração aguda ou crônica com a fluoxetina ou a imipramina. Nestes mesmos animais, foram também avaliado o número de células triptofano hidroxilase positivas. Para fins comparativos, o efeito do tratamento com a imipramina em animais submetidos à esquiva inibitória também foi avaliado. A análise imunoistoquímica indicou que a tarefa de fuga promoveu um aumento na expressão da proteína Fos em neurônios nãoserotonérgicos localizados na sub-região das asas laterais do NDR. Efeito este que não foi observado em animais tratados cronicamente com a fluoxetina e a imipramina. Além disso, o tratamento prolongado com a fluoxetina, mas não com a imipramina, foi capaz de aumentar a ativação de neurônios serotonérgicos nesta mesma sub-região. Diferente do que foi observado na tarefa de fuga, a tarefa de esquiva inibitória promoveu um aumento na ativação de neurônios serotonérgicos nas sub-regiões DRC, DRD e DRV. Perfil que não foi observado nos grupos aguda e cronicamente tratados com imipramina. Além disso, somente o tratamento prolongado com a imipramina promoveu uma diminuição no recrutamento de neurônios não-serotonérgicos em diversas sub-regiões do NDR. Diante do resultado imunoistoquímico observado no experimento com a fluoxetina, avaliamos a participação dos autorreceptores 5-HT1A das asas laterais no efeito observado. Através da técnica whole-cell patch clamp, em uma linhagem de camundongos transgênicos que apresenta neurônios serotonérgicos fluorescentes, foi avaliada a responsividade destes receptores após o tratamento com a fluoxetina. Os resultados indicam que os animais tratados cronicamente com fluoxetina apresentam aumento na excitabilidade basal com diminuída sensibilidade ao agonista de receptores 5-HT1A, 8-OHDPAT. Assim, é possível sugerir que o efeito antipânico da fluoxetina administrada cronicamente parece estar relacionado com uma redução na ativação de neurônios não-serotonérgicos e um aumento no recrutamento de neurônios serotonérgicos localizados nas asas laterais, sendo que esta última pode ser explicada pela dessensibilização dos autorreceptores 5-HT1A. Com relação à imipramina, é possível sugerir que o efeito panicolítico promovido pelo tratamento prolongado pode ser devido à diminuição no recrutamento de neurônios não-serotonérgicos das asas laterais. Já para o efeito ansiolítico, tanto a diminuição no recrutamento de neurônios não-serotonérgicos em diferentes sub-regiões do NDR, quanto a diminuição na ativação de neurônios serotonérgicos no DRC, DRD e DRV parecem estar envolvidas. / A wealth of evidence indicates that the dorsal raphe nucleus (DR) is a heterogeneous structure, composed of anatomically and functionally distinct populations of serotonergic neurons, which have been differently implicated in the pathophysiology of anxiety, such as panic disorder. Antidepressant drugs are the first choice in treatment of anxiety disorders, and the delay for the therapeutic effect have consistently been associated with changes in serotonergic neurotransmission within the DR. However, it is unknown whether these alterations can be heterogeneous among the different subregions of the DR, and this is the focus of investigation of the present study. First, it was investigated the profile of neuronal activation of different subregions of the DR - by using the evaluation of Fos protein expression of rats exposed to the escape task in the elevated T-maze test, after acute or chronic administration of fluoxetine or imipramine. In the same animals, it was also investigated the number of positive triptophan hidroxylasis cells. For comparative reasons, it was evaluated the behavioral and immunohistochemical effects of imipramine treatment on inhibitory avoidance acquisition in the elevated T-maze, a response associated with anxiety. The results of the immunohistochemical analysis indicated that animals exposed to escape behavior exhibited higher expression of Fos protein in non-serotonergic neurons in the DR lateral wings. This effect was not observed in fluoxetine or imipramine chronically treated animals. Moreover, chronic treatment with fluoxetine, but not imipramine, was able to increase the activation of serotonergic neurons on this subregion. On the other hand, the inhibitory avoidance task promoted an increase in the activation of serotonergic neurons in the sub-regions DRC, DRD, and DRV. This profile was not observed after acute or chronic treatment with imipramine. Additionally, only the long-term treatment with imipramine showed a decrease in the activation of non-serotonergic neurons in different subregions of the DR. Based on the results obtained with fluoxetine experiment, we evaluated the role of the 5-HT1A autoreceptors located in the lateral wings. For this, we used the whole-cell patch clamp technique in a transgenic mouse line, which exhibit fluorescence in serotonergic neurons. The results indicate that the animals treated chronically with fluoxetine presented an increase in the basal excitability, with lower responsivity to the 5-HT1A agonist - 8-OH-DPAT. Altogether, the results suggest that the anti-panic effect caused by chronic fluoxetine treatment is associated with a reduction in the activation of non-serotonergic neurons, and an increase in the recruitment of non-serotonergic neurons in lateral wings. This last observation seems to be related to a 5-HT1A autoreceptor desensitization in the lateral wings. Regarding imipramine, this panicolytic effect caused by chronic administration of this drug seems to be related to a decreased activation of the non-serotonergic neurons in the lateral wings. Finally, the anxiolytic effect, of imipramine may be associated to a decrease in the recruitment of non-serotonergic neurons in different DR subregions, allied with a decreased activation of serotonergic neurons in the DRC, DRD and DRV.

Submitted by Marcos Anselmo (marcos.anselmo@unipampa.edu.br) on 2016-04-07T17:26:59Z No. of bitstreams: 1 Franciele Donato.pdf: 1097306 bytes, checksum: d397f421e694919bc9400a3137762b3e (MD5) / Made available in DSpace on 2016-04-07T17:27:00Z (GMT). No. of bitstreams: 1 Franciele Donato.pdf: 1097306 bytes, checksum: d397f421e694919bc9400a3137762b3e (MD5) Previous issue date: 2013-01-17 / A depressão é um transtorno mental comum associado a um significativo impacto negativo na qualidade da vida. Morbidade/mortalidade e função cognitiva. A teoria das monoaminas da depressão postula que esta doença resulta de uma deficiência na atividade monoaminérgica no cérebro. No entanto, outros sistemas neurais e processos bioquímicos, como o estresse oxidativo, parecem estar envoltos na sua patogênese. Os objetivos desse estudo foram investigar o efeito tipo antidepressivo e toxidade aguda do fenilselenometil-..-triazol(Se-TZ). (um suposto orgânico heterocíclico contendo selênio), administrado pela via oral em camundongos. Os resultados obtidos evidenciaram que a administração de Se-TZ, reduziu significativamente o tempo de imobilidade no teste de suspenção da cauda (TSC), sem alterar a atividade locomotora e exploratória no teste de campo aberto (tca). O efeito tipo antidepressivo de Se-TZ no TSC foi bloqueado pelo pré-tratamento dos camundongos com SCH23390 (0,05 mg/kg, s.c., antagonista seletivo do receptor D1), sulpirida (50 mg/kg, i.p.. antagonista seletivo do receptor D2) e metisergida (2mg/kg, s.c.. antagonista não seletivo dos receptores 5-HT), mas não com prazosin (1 mg/kg, i.p, antagonista de receptores α1- adrenérgico), ioimbina (1 mg/kg i.p., antagonista de receptores α2-adrenérgicos) e propranolol (2 mg/kg, i.p, antagonista não seletivo β-adrenérgico). A determinação dos níveis de neurotransmissores monoaminérgicos e seus metabólitos colaborou com os resultados obtidos anteriormente no TSC. Neste contexto, o Se-TZ, aumentou os níveis dos neurotransmissores monoaminérgicos dopamina (DA) e serotonina (5-HT) no córtex cerebral e no hipocampo. enquanto que os níveis de norepinefrina (NE), não foram alterados. Este estudo também mostrou que 72 horas após a administração do Se-TZ, os parâmetros de toxidade aguda aspartato aminotransferase (AST), alanina aminotransferase (ALT) uréia e creatinina, não foram alterados além disso, os resultados evidenciaram que a exposição ao Se-TZ causou um aumento significativo na atividade de catalase (CAT) no córtex cerebral e no hipocampo, no entanto, a glutadiona S-transferase (GST) aumentou apenas no córtex cerebral. A peroxidação lipídica e os níveis de tióis não-protéicos (NPSH) não foram alterados. Estes resultados sugerem que o Se-TZ apresentou efeito tipo antidepressivo. Mediado através do sistema neurotransmissor dopaminérgico (D1 e D2) e serotoninérgicos, sem causar toxidade aguda nos marcadores bioquímicos de lesão hepática e renal avaliados. / Depression is a common mental disorder associated whth a signigicant negative impact n quality of life, morbidity, and cognitive function. The monoamine theory of depression postultes that this disease results from a deficiency of brain monoaminergie activity, however other neural systems and biochemical process, like oxidative stress, appear to be involved in its pathogenesis. The aims of the study were investigated the antidepressant like effect, acute toxicity of 4-phenyl-1-(phenylselanylmenthyl)-1,2,3-trizole (Se-TZ), (an organocompounds selenium-containing heterocycles), administered by oral route, in mice. The results evidenced that administration of Se-TZ, significantly reduced immobility time in tail suspension test (TST), without altering locomotor and exploratory activity in the open-field test (OFT). The antidepressant-like effect of Se-TZ ib the TST was prevented by pretreatment of miche with SCH23390 (0,5 g/Kg, s. s, selective D1 receptor antagonist), sulpiride (50 mg/Kg, i.p., selective D2 receptor antagonist) and methysegide ( 2 mg/Kg, s.c., non-selective 5-HT receptors antagonist), but not with prazosin ( 1 mg/Kg, i.p., an α 1 –adrenoreceptor antagonist), yohimbine ( 1 mg/Kg, i.pi.; an α 2-adrenoreceptor antagonist) and propranolol (2 mg/Kg i.p.; β-adrenoreceptor antagonist). The determination of levels of monoamine neurotransmitters and their metabolites cooperating with results obtained previously in TST. In this context, the Se-TZ, increased monoamine neurotransmitters dopamine (DA) an serotonin (5-HT) levels in the cerebral cortex an hippocampus, whereas norepinephrine (NE) levels, were not altered. This study also showed that 72 hours after administration of single oral dose of Se-TZ, the paramenters of acute toxicity to biochemical makers hepatic damage: aspartate aminotransferase (AST) and alanine aminotransferase (ALT) and renal: urea and creatinine, were not altered. Furthermore, the results evidenced that exposure to Se-TZ caused a significant increase in the catalase (CAT) activity in the cerebral cortex and hippocampus, however the glutathione S-tranferase CGST) activity increased only in cerebral cortex. The lipid peroxidation and NPSH (non protein thiols) levels, were not changed. These results suggest that the Se-TZ presented antidepressant effect, mediated through the dopaminiergie (D1 and D2) and serotonergie neurotransmitter systems, without causing acute toxicity in biochemical makers of liver and kidney damage evaluated.

Espécies do gênero Valeriana são tradicionalmente utilizadas para tratar ansiedade, irritabilidade e desordens de sono. A Organização Mundial da Saúde indica o uso de preparações farmacêuticas como alternativa aos benzodiazepínicos para tratamento da ansiedade e insônia. Entre as substâncias ativas presentes no gênero Valeriana destacam-se os óleos voláteis, valepotriatos, flavonóides e lignanas. Entretanto, estudos farmacológicos com produtos isolados são escassos. Espécies nativas de Valeriana, que ocorrem no Rio Grande do Sul, têm sido estudadas em relação a sua composição química, sendo a espécie Valeriana glechomifolia a que possui maior teor de valepotriatos. Neste estudo, diferentes métodos de extração de valepotriatos foram comparados e extratos enriquecidos em valepotriatos foram testados em modelos animais de sedação, ansiedade e depressão. Valepotriatos isolados foram submetidos a ensaios de ligação a receptores benzodiazepínico e serotonérgico (5HT1A) e ensaios de atividade da enzima Na+K+ATPase. A extração por fluido supercrítico com dióxido de carbono (SCCO2) foi realizada em temperatura constante de 40 oC e pressões variáveis (90, 120, 150 e 200 bar) e demonstrou maior teor de valepotriatos que os métodos de extração por maceração em ultrassom e maceração Entre as diferentes pressões de extração utilizadas no método de SCCO2, o maior teor de valepotriatos foi apresentado pela fração obtida na pressão de 90 bar. Todos os extratos mostraram o mesmo perfil qualitativo de valepotriatos. Flavonóides também foram obtidos através de maceração por ultrassom em metanol. A dose letal mediana dos valepotriatos obtidos por maceração por ultrassom foi de 42±3 mg/kg, i.p. Esta mesma solução extrativa, na dose de 10 mg/kg, v.o. (gavage), foi inefetiva no labirinto em cruz elevado e tempo de sono barbitúrico, sugerindo a ausência de propriedades ansiolíticas e hipnótico-sedativas. Resultados similares foram obtidos com a solução extrativa enriquecida em flavonóides. Valtrato, acevaltrato, 1-b-acevaltrato, diavaltrato e o flavonóide codificado como B6 não apresentaram ligação ao sítio benzodiazepínico do complexo receptor GABAA, nem ao receptor serotonérgico (5HT1A) viii na faixa de concentração de 1-100 μM. Os valepotriatos inibiram a atividade da enzima Na+K+-ATPase na faixa de concentração micromolar. A fração de valepotriatos obtida por SCCO2 (10 mg/kg, gavage) foi efetiva no teste da natação forçada, sem interferir na atividade locomotora espontânea, sugerindo uma atividade do tipo antidepressiva. Em conclusão, a extração por fluido supercrítico com dióxido de carbono mostrou-se eficiente para a obtenção de frações enriquecidas em valepotriatos e estas substâncias representam uma nova classe química com atividade inibitória não seletiva da enzima Na+K+ATPase, e com atividade do tipo antidepressiva. / Species of the genus Valeriana are traditionally used to treat anxiety, irritability and sleep disorders. The World Health Organization indicates pharmaceutical preparations of V. officinalis as an alternative to benzodiazepine drugs for treating anxiety and insomnia. Volatile oil, valepotriates, flavonoids and lignan have been suggested as active substances of the Valeriana genus. However pharmacological studies on isolated compounds are scarce. Species of Valeriana native to Rio Grande do Sul have been studied regarding their chemical composition being Valeriana glechomifolia the species with highest valepotriate’ contents. In this study different methods of extraction of valepotriates from aerial parts of V. glechomifolia were compared, and valepotriate’ enriched extracts were tested in mice models of sedation, anxiety and depression. Isolated valepotriates were submitted to binding to benzodiazepine and 5HT1A receptors, and assayed for the Na+K+ATPase inhibitory activity. The extraction by supercritical carbon dioxide (SCCO2) was carried out at 40 oC under 90, 120, 150 or 200 bar affording higher valepotriates contents than maceration with dichloromethane and ultrasound. The highest valepotriates yielding was obtained with SCCO2 (40 oC , 90 bar). All extracts presented the same qualitative valepotriate’ profile. Flavonoids were also obtained from methanol extracts. The median lethal dose of valepotriates obtained by maceration was determined as 42±3 mg/kg, i.p. This valepotriate’ enriched extract (10 mg/kg, p.o., gavage) was ineffective in the elevated plus maze and barbiturate sleeping time tests suggesting that it does not present anxiolitic or hypnotic-sedative properties. Similar results were obtained with flavonoids’ enriched extract. Valtrate, acevaltrate, 1-b-acevaltrate, diavaltrate and the flavonoid named B6 did not bind to benzodiazepine site of receptor GABAA complex neither to serotonergic receptor (5HT1A) at 1-100 μM. The valepotriates inhibited the Na+K+ATPase activity at micromolar concentration range. The valepotriates fraction obtained by SCCO2 (10 mg/kg, gavage) was effective in the forced swimming test without interfering with the spontaneous locomotor activity suggesting that it presents an antidepressant-like activity. In conclusion the extraction by supercritical carbon dioxide is valuable to obtain valepotriates enriched fractions; and valepotriates seem to represent new chemical entities with no selective inhibitory activity of Na+K+ATPase, as well as with antidepressant-like activity.

Tratamentos alternativos para a depressão humana vêm sendo realizados pela homeopatia e fitoterapia, por meio do Hypericum perforatum (Hp), dinamizado ou extrato, respectivamente. Experimentalmente, o desamparo aprendido é proposto como modelo animal de depressão, o que permite seu uso para o teste de substâncias potencialmente antidepressivas. Assim, foram realizados dois experimentos para verificar se o Hp em preparação homeopática e fitoterápica impediriam o desamparo aprendido em animais. No Experimento 1, foram utilizados 96 ratos Wistar, machos, distribuídos em doze grupos (n=8), expostos às fases choque e teste, separadas por 24h. Os grupos foram manipulados em tríades, tratados com choques (60, 1,0 mA, VT 60s, 10s máx.) controláveis (C), incontroláveis (I) ou nenhum choque (N). Após esse tratamento, as tríades receberam 5 gotas, v.o. de: Hp 30CH, Hp 200CH e 0CH (veículo - solução hidroalcóolica a 5%), três vezes, com intervalo de 0, 19 e 23h após o término da fase choque. A quarta tríade não recebeu substância (sd) e foi utilizada para comparação em ambos os experimentos. No teste, todos os sujeitos foram submetidos a uma contingência de fuga, com 30 choques, semelhantes aos anteriores, em uma shuttlebox. No Experimento 2, foram utilizados 72 ratos com as mesmas características, distribuídos em nove grupos (n=8). Os equipamentos foram os mesmos e o procedimento foi semelhante ao do Experimento 1, com diferença apenas na fase de administração da droga, sendo que cada tríade recebeu extrato de Hp i.p., 1ml/kg, nas doses: 0mg/kg (veículo - solução hidroalcóolica a 5%), 15 mg/kg e 30 mg/kg, 22 horas após o término da fase choque. Os resultados mostraram que apenas o Grupo I da Tríade sd apresentou desamparo aprendido. No Experimento 1, as substâncias não produziram efeito sobre os grupos N e C, enquanto os grupos I tiveram redução das latências, sendo o efeito mais significativo com Hp 200CH. O tratamento 0CH produziu uma pequena redução das latências gerais, embora não suficiente para abolir o desamparo. Os resultados do Experimento 2 mostraram que os grupos N e C não sofreram efeito das substâncias, enquanto os grupos I tiveram redução da suas latências, sendo o efeito maior com Hp 0 mg/kg. Esses resultados sugerem que o veículo não era farmacologicamente inerte, comprometendo os demais resultados do Hp. Conclui-se que os efeitos de tratamentos da homeopatia e fitoterapia precisam ser mais investigados para que uma afirmação da sua eficácia tenha mais confiabilidade. / Alternative treatments for the human depression have been conducted in the homeopathy and phytoterapy, through Hypericum perforatum (Hp), dynamized or extract, respectively. Experimentally, learned helplessness is proposed as an animal model of depression, which permits its use to test the effects of potential antidepressants. Two experiments were conducted to investigate whether Hp, either in homeophatic and or in phytotherapic preparation, can prevent the occurrence of learned helplessness in animals. In the Experiment 1, 96 male Wistar rats were divided into 12 groups (n=8) exposed to treatment and test phases, separated by 24 hours. Groups were divided into triads exposed to controllable shocks (C), uncontrollable shocks (I) or no shocks (N). After that, Hp was administered orally (five drops) to each triad in one of three dynamizations – 30CH, 200CH and 0CH (vehicle - hydroalcoholic solution 5%) – three times: 0, 19, and 23 hours after treatment with shocks. The fourth triad didn’t receive drug (sd) and it was used in both experiments. In the test phase, all the animals were exposed to an escape contingency in a shuttlebox. In the Experiment 2, 72 rats were divided into 9 groups (n=8). Equipments were the same and procedure was similar to Experiment 1, with the exception of drug administration. Extract of Hp was administered, i.p., 1 ml/kg, in one of three concentrations for each triad – 0 mg/kg (vehicle – hydroalcoholic solution 5%), 15 mg/kg and 30 mg/kg - 22 hours after treatment with shocks. Results showed that, among the groups that were not administered pharmacological treatment, only Group I did not learn to escape, an indication of learned helplessness. In Experiment 1, among the groups that were administered Hp in homeopathic preparation, groups N and C were not affected, while response latencies for groups I decreased, with a stronger effect with 200CH. Treatment with 0CH caused a small reduction of general latencies, although it wasn’t suficient to prevent helplessness. In Experiment 2, results showed that Hp in phytotherapic administration didn’t affect groups N and C, while the latencies of Group I were reduced, with a stronger effect with Hp 0mg/kg. These data suggest that the vehicle wasn’t inert pharmacologically, which casts doubt on the results that involved Hp. In conclusion, more studies will be necessary to attest the efficacy of homeopathic and phytotherapic treatment.

Electroconvulsive therapy (ECT) effectively treats depression by administration of repeated seizure-inducing electrical stimuli. Sprague-Dawley rats were administered 6 electroconvulsive shocks (ECS) over 2 weeks, and in vivo single unit extracellular electrophysiological activity was recorded after 48 hours. Overall firing activity in the locus coeruleus and ventral tegmental area was unchanged, suggesting the therapeutic efficacy of ECT may not be attributed to increased norepinephrine and dopamine release. There were more spontaneously active neurons in the substantia nigra pars compacta (SNc), indicating greater dopamine tone in the nigrostriatal motor pathway, which may contribute to alleviation of psychomotor retardation. In the facial motor nucleus (FMN), locally administered norepinephrine, but not serotonin, facilitated greater glutamate-induced firing, which may contribute to improved facial motricity. Current results indicate that repeated ECS enhances postsynaptic norepinephrine neurotransmission in the FMN and SNc dopamine neurotransmission, which could represent the mechanism behind the alleviation of depressive symptoms including psychomotor retardation.

Electroconvulsive therapy (ECT) effectively treats depression by administration of repeated seizure-inducing electrical stimuli. Sprague-Dawley rats were administered 6 electroconvulsive shocks (ECS) over 2 weeks, and in vivo single unit extracellular electrophysiological activity was recorded after 48 hours. Overall firing activity in the locus coeruleus and ventral tegmental area was unchanged, suggesting the therapeutic efficacy of ECT may not be attributed to increased norepinephrine and dopamine release. There were more spontaneously active neurons in the substantia nigra pars compacta (SNc), indicating greater dopamine tone in the nigrostriatal motor pathway, which may contribute to alleviation of psychomotor retardation. In the facial motor nucleus (FMN), locally administered norepinephrine, but not serotonin, facilitated greater glutamate-induced firing, which may contribute to improved facial motricity. Current results indicate that repeated ECS enhances postsynaptic norepinephrine neurotransmission in the FMN and SNc dopamine neurotransmission, which could represent the mechanism behind the alleviation of depressive symptoms including psychomotor retardation.

Depressive disorders are among the most frequent psychiatric diseases in the Western world with prevalence between 9% and 18%. Poor compliance and inappropriate antidepressant discontinuation invokes long-term morbidity, and appear linked to hippocampal shrinkage. Despite major advances in pharmacological treatment of the illness over the past 3040 years, currently available agents have distinct shortfalls both in clinical efficacy and in maintenance of response. This implies a greater long-term morbidity with significant impact on the patient, the patient's family as well as economic implications to health care managers and providers. The major reason for this state of affairs is our poor understanding of the neurobiology of depression and hence, of antidepressant (AD) action. AD drugs are thus not addressing the crucial neurobiological target underlying the illness, and new strategies and treatments are urgently needed. In recent years, depression has been associated with disturbances in excitotoxic glutamatergic activity, yet this has not been systematically evaluated. While the role of neurotransmitters such as serotonin, noradrenaline and dopamine has been extensively studied, new evidence suggests a role for the unique neurotransmitter nitric oxide (NO). Nitric oxide (NO), is activated by glutamatergic systems in various limbic and other regions of the brain, and has recently also been implicated in anxiety and affective disorders. Of special interest is the putative role of NO in cellular memory, synaptic plasticity and cell survival, all-important processes in the neuropathology and neurodevelopment of depression. Recent clinical studies have provided evidence of the role of the NO-pathway in depression, while preclinical studies have demonstrated the anxiolytic and antidepressant actions of nitric oxide synthase (NOS)-inhibitors. Moreover, NO interacts with other classical transmitters that have a regulatory role on mood, particularly the monoamines, as well as glutamate and gammaaminobutyric acid (GABA). In the current study the role of the NO-cGMP pathway in AD action was investigated, after chronic imipramine (IMI) and after IMI withdrawal, using a learned helplessness paradigm. Behavioural changes, hippocampal NOS activity and cGMP accumulation was determined together with pharmacological manipulation of the NO-cGMP pathway. Chronic IMI, 15 mg/kg/day intraperitoneal (ip) administration induced a pronounced reduction in swim immobility time in the forced swim test (FST), with no effect on horizontal or vertical locomotor activity. These behavioural changes were accompanied by a significant reduction in NOS enzyme activity and cGMP accumulation. In order to confirm the involvement of the NO-cGMP pathway in the AD action of IMI, chronic (3 weeks) IMI treatment was followed by an acute withdrawal of 7 days. Acute withdrawal, after chronic IMI treatment, resulted in a significant increase in swim immobility time and an increase in NOS enzyme activity and cGMP levels. In fact, NOS activity was raised above that of control, not just higher than the effect of chronic IMI. In order to assess the possible role of the NMDA-NO-cGMP pathway in AD withdrawal, the NMDA receptor antagonist, memantine, and the NOS/guanylyl cyclase (GC) inhibitor, methylene blue (MB), were administered during the 7 day IMI withdrawal period. Memantine (5 mg/kg/d ip), during the 7 day IMI withdrawal period, significantly reversed the increase in immobility time evoked after IMI withdrawal. This was accompanied by a significant reduction in NOS enzyme activity and a tendency to decrease cGMP levels. This data confirms that the antidepressant action of IMI, as well as IMI withdrawal, is associated with actions on the NMDA-GIu-NO-cGMP pathway. Particularly. IMI withdrawal evokes an increase in glutamate activity that is responsible for NOS activation. During the 7 day IMI withdrawal period, MB (15 mg/kg/d ip) also significantly reversed the increased immobility time after IMI withdrawal and was accompanied by a tendency to decrease NOS enzyme activity and cGMP levels in the rat hippocampus, however statistical significance was not reached. Although not emphatic, this data implies a possible role of the NO-cGMP pathway in AD action and AD withdrawal. In order to determine whether the observed IMI withdrawal effects on the NO-cGMP pathway may occur through an initial destabilisation in the serotonergic system, the 5-HT2a/2c receptor antagonist, ritanserin (4 mg/kg/d ip), was administered during the IMI withdrawal period. These studies revealed that antidepressant withdrawal evokes an increase in 5-HT2-mediated activity, and that antidepressant-induced NOS activation after withdrawal has its origin in serotonergic hyperactivity. Clearly, this is supportive of a distinct relationship between the NO and serotonergic system in antidepressant response. On its own, ritanserin was found to increase NOS and cGMP levels, yet during IMI withdrawal this response was lost, suggesting that IMI withdrawal alters the response to a 5-HT2a/2c receptor antagonist, which may have major clinical implications. In conclusion, the AD action of IMI, as well as chronic IMI withdrawal, involves actions on the NO-cGMP pathway. Withdrawal of ADS is associated with a loss of AD efficacy together with an increase in release of NO and cGMP. The NMDA antagonist, memantine, and the NOS/GC inhibitor, MB, reversed these responses therefore suggesting that the NMDA-GIu-NO-cGMP pathway may be a new putative target in understanding the neurobiology of AD action. Finally, NOS activation following withdrawal suggest that inappropriate withdrawal during the treatment of depression may mediate neurodegenerative pathology observed in recurrent depression, possibly by severely increased hippocampal NOS activity which is toxic to neurons. / Thesis (M.Sc. (Pharmacology))--North-West University, Potchefstroom Campus, 2005.

Genetic factors have been shown to be involved in etiology of a poor response to the antidepressant treatment with sufficient dosage and duration. Our goal was to identify the role of polymorphisms in the poor response to the treatment. To this end, 5 functional polymorphisms in 109 patients diagnosed with unipolar, major depressive disorder are analyzed. Due to the small sample size, exact conditional tests are utilized to analyze the contingency table. The data analysis involves: (1) Exact test for conditional independence in a high dimensional contingency table; (2) Marginal independence test; (3) Exact test for three-way interactions. The efficiency of program always limits the application of exact test. The appropriate methods for enumerating exact tables are the key to improve the efficiency of programs. The algorithm of enumerating the exact tables is also introduced.

Evidence suggests that selective serotonin reuptake inhibitors (SSRIs, a class of antidepressant medications) may contribute to increased breast cancer risk by stimulating the secretion of prolactin, a potential tumour promoter. The main objective of this study was to determine breast cancer risk associated with the duration, dosage and timing of SSRI use among women, with control for a limited set of confounders. This thesis project, conducted within the context of a population-based two-stage case-control study, consisted of a record linkage study utilizing three Saskatchewan health services databases. Cases included 1,273 women with primary breast cancer diagnosed between January 1, 2003 and December 31, 2005, and controls consisted of 12,730 subjects randomly selected from the province’s population registry. Data on SSRI use was compiled from the Saskatchewan prescription drug plan database. Information on a limited set of established risk factors for breast cancer that may confound this relationship was ascertained from the population registry and the prescription database. Cases and controls were similar in terms of age, total number of consecutive years eligible for prescription coverage and indicators of socioeconomic status. Compared to controls, cases were more likely to be married and to have used hormone therapy and/or oral contraceptives. Compared to nonusers, results indicated that the use of SSRIs for three or more years (as estimated by having filled 36 or more prescriptions for all SSRIs combined during the main exposure window more than two years prior to index date) was not associated with an increased risk of breast cancer (OR= 1.08, 95% CI: 0.74-1.58), controlling for age, marital status, oral contraceptive and hormone therapy use. In addition, no suggestion of increased risk was detected for long-term exposures to individual SSRIs (24 or more prescriptions filled during the main exposure window) and in relation to total combined SSRI use 2-7 years and more than seven years prior to index date. However, these risk estimates may have been affected by potential sources of information bias and confounding. In summary, these results do not provide evidence to suggest that the risk of breast cancer is increased with the use of SSRIs. / Thesis (Master, Community Health & Epidemiology) -- Queen's University, 2008-01-08 13:51:38.74