Influência da restrição alimentar associada ou não à privação de sono paradoxal na arquitetura de sono e comportamento sexual de ratos machos
Arquivos
Data
2008
Autores
Alvarenga, Tathiana Aparecida Fernandes 
Orientadores
Tufik, Sergio
Tipo
Dissertação de mestrado
Título da Revista
ISSN da Revista
Título de Volume
Resumo
A restrição alimentar (RA) é caracterizada pela redução da quantidade total de alimento ingerido, e tem sido utilizada espontaneamente por muitos indivíduos para aumentar a expectativa de vida. Embora a diversidade de benefícios provocados pela baixa ingestão calórica tenha sido muito estudada, as conseqüências da RA no
padrão de sono e na resposta sexual em modelos animais ainda permanecem como uma área pouco estudada. Por outro lado, a privação de sono, uma condição cada vez mais prevalente na nossa sociedade, resulta em efeitos adversos ao organismo, exceto pela ação antidepressiva e por aumentar os reflexos genitais em ratos. Nesse sentido, o objetivo do presente estudo foi analisar a arquitetura de sono (Artigo 1), avaliar os reflexos genitais (Artigo 2), e por fim, o comportamento sexual e o perfil hormonal (Artigo 3) em ratos submetidos à RA. A partir do desmame, ratos machos Wistar foram distribuídos em 2 grupos: a) mantido com ração ad libitum (AD), e b)
submetidos a RA (6 gramas diárias de ração/animal). Essa quantidade de ração foi aumentada em 1g/semana até totalizar 15g na idade adulta. Para realização dos experimentos referentes ao Artigo 1, foram implantados eletrodos para registro de sono (72 horas). Quanto ao padrão de sono, a RA acarretou marcantes alterações na distribuição do ciclo vigília-sono em virtude do aumento do tempo de sono durante o
período escuro e diminuição durante a fase clara, efeito oposto ao padrão normal apresentado por esses animais. Para os experimentos referente ao Artigo 2, os animais foram submetidos à privação de sono paradoxal (PSP) pelo método da plataforma múltipla durante 96 horas e desafiados com administração aguda de salina ou cocaína antes da avaliação dos reflexos genitais. Verificou-se que os
animais submetidos a RA crônica e posteriormente a PSP não apresentaram um aumento de reflexos genitais mesmo quando desafiados com cocaína. Para os experimentos de comportamento sexual (Artigo 3), os animais também foram submetidos à PSP ou mantidos em gaiolas de moradia. Foi observada uma diminuição da motivação e do desempenho sexual em ambos os grupos PSP (RA e
AD) comparados ao grupo CTRL. No entanto, a RA minimizou os efeitos da PSP, uma vez que somente o grupo RA-PSP não apresentou uma diminuição do número de ejaculações. Em relação às dosagens hormonais observamos que ambos os grupos submetidos à PSP tiveram as concentrações de testosterona diminuídas em
relação aos respectivos grupos controles, enquanto que a progesterona apresentou um aumento significativo somente no grupo RA-PSP em relação ao grupo RA-CTRL. Nossos resultados demonstram que a RA acarretou marcantes alterações na distribuição do ciclo vigília-sono, e que embora a RA promova efeitos positivo como de aumentar a longevidade, quando associada a uma situação de falta de sono
diminui a resposta sexual.
Food restriction (FR) can be characterized by the reduction of total food intake and has been exercised by many as a means to increase life span. Although the plethora of benefits that low calorie ingestion promotes has been thoroughly examined, the consequences of FR on the sleep pattern and in sexual response in animal models remain to be investigated. It is fact that sleep derivation leads to adverse physiological effects, among which are anti-depressive action and increase of genital reflexes in rats. Thus, the current investigation purported to examine the sleep architecture (Article 1), assess genital reflexes (Article 2), and lastly, observe the sexual behavior and hormonal profile (Article 3) of rats submitted to FR. Once weaned, male Wistar rats were distributed into 2 groups: a) kept with chow ad libitum (AD), and b) those submitted to FR (6 grams of chow daily). The amount of chow was increased 1g/week up to 15g in adulthood. For the experiments described in Article 1, electrodes were implanted for sleep recording (72h). In regards to the sleep pattern, FR led to marked alterations in the distribution of the sleep/wake cycle because of the longer period of sleep in the dark period and reduction of sleep in the light period, a scenario opposite to the normal pattern in these animals. For the experiments of Article 2 the animals were submitted to paradoxical sleep deprivation (PSD) by the multiple platform method for 96h and challenged with acute administration of saline solution or cocaine prior to the assessment of genital reflexes. It was found that the chronic FR animals that underwent PSD did not present increase of genital reflexes not even when challenged with cocaine. For the sexual behavioral studies (Article 3) the animals were also submitted to PSD or kept in home cages. A decrease in motivation and sexual performance was observed in both groups (FR and AD) when compared to controls. However, FR minimized the PSD effects as it was only the FR-PSD group that did not present reduction in the number of ejaculations. As for hormonal concentrations it was verified that both groups submitted to PSD had their testosterone concentrations reduced in relation to their respective controls, while progesterone increased significantly only in the FR-PSD group when compared to the FR-CTRL group. Our results show that FR led to marked alterations in the distribution of the sleep/wake cycle and that although FR does promote positive effects like longer lifespan, it reduces sexual response when associated to shortage of sleep.
Food restriction (FR) can be characterized by the reduction of total food intake and has been exercised by many as a means to increase life span. Although the plethora of benefits that low calorie ingestion promotes has been thoroughly examined, the consequences of FR on the sleep pattern and in sexual response in animal models remain to be investigated. It is fact that sleep derivation leads to adverse physiological effects, among which are anti-depressive action and increase of genital reflexes in rats. Thus, the current investigation purported to examine the sleep architecture (Article 1), assess genital reflexes (Article 2), and lastly, observe the sexual behavior and hormonal profile (Article 3) of rats submitted to FR. Once weaned, male Wistar rats were distributed into 2 groups: a) kept with chow ad libitum (AD), and b) those submitted to FR (6 grams of chow daily). The amount of chow was increased 1g/week up to 15g in adulthood. For the experiments described in Article 1, electrodes were implanted for sleep recording (72h). In regards to the sleep pattern, FR led to marked alterations in the distribution of the sleep/wake cycle because of the longer period of sleep in the dark period and reduction of sleep in the light period, a scenario opposite to the normal pattern in these animals. For the experiments of Article 2 the animals were submitted to paradoxical sleep deprivation (PSD) by the multiple platform method for 96h and challenged with acute administration of saline solution or cocaine prior to the assessment of genital reflexes. It was found that the chronic FR animals that underwent PSD did not present increase of genital reflexes not even when challenged with cocaine. For the sexual behavioral studies (Article 3) the animals were also submitted to PSD or kept in home cages. A decrease in motivation and sexual performance was observed in both groups (FR and AD) when compared to controls. However, FR minimized the PSD effects as it was only the FR-PSD group that did not present reduction in the number of ejaculations. As for hormonal concentrations it was verified that both groups submitted to PSD had their testosterone concentrations reduced in relation to their respective controls, while progesterone increased significantly only in the FR-PSD group when compared to the FR-CTRL group. Our results show that FR led to marked alterations in the distribution of the sleep/wake cycle and that although FR does promote positive effects like longer lifespan, it reduces sexual response when associated to shortage of sleep.
Descrição
Citação
ALVARENGA, Tathiana Aparecida Fernandes. Influência da restrição alimentar associada ou não à privação de sono paradoxal na arquitetura de sono e comportamento sexual de ratos machos. 2008. 138 p. Dissertação (Mestrado em Ciências) - Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, 2008.