Papel do zinco sobe a fertilidade e função testicular de ratos expostos ao tabaco
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Data
2008-02-18
Autores
Garcia, Patrícia Carvalho [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
Aproximadamente um terço da população mundial é tabagista. Devido ao fato de ser um carcinógeno que causa mutações nas células somáticas, o tabaco pode afetar a saúde reprodutiva masculina. No homem o tabagismo é um fator de risco para o desenvolvimento de diversas enfermidades urológicas, embora o mecanismo exato de atuação seja ainda desconhecido. Por outro lado, ao analisarmos os aspectos reprodutivos, verificamos que o zinco é essencial para a espermatogênese como um co-fator de metaloenzimas envolvidas na transcrição do DNA, na expressão dos receptores esteróides e na síntese protéica, bem como apresenta ação anti-oxidante e anti-apoptótica. Com base nestas informações, o objetivo do presente trabalho consistiu em analisar o papel do zinco sobre a fertilidade e função testicular de ratos expostos ao tabaco. Ratos Wistar com 60 dias de idade (n=10/grupo) foram divididos em quatro grupos G1 (grupo controle), G2 (expostos a fumaça do tabaco-20 cigarros/dia), G3 (grupo controle suplementado com zinco-20mg/Kg cloreto de zinco diariamente por gavagem) e G4 (expostos a fumaça do tabaco e suplementados com zinco). A duração do tratamento foi de oito semanas. Ao final do experimento foram avaliados os seguintes parâmetros: massa corporal, peso úmido dos órgãos da reprodução e da glândula adrenal, concentração plasmática de testosterona, função testicular (análise seminal e produção diária de espermatozóides), fertilidade e comportamento sexual. As respostas farmacológicas da musculatura lisa genital acessória masculina (vesícula seminal e ducto deferente) a drogas autonômicas e danos no DNA do espermatozóide foram também avaliados. Os resultados foram comparados entre si pela análise de variância não-paramétrica, para modelo com dois fatores, complementada com teste de comparações múltiplas de Tukey, p<0,05...
About one-third of the world's male population smokes tobacco daily. Considering the larger number of men worldwide who smoke, and that cigarette is a known somatic cells mutagen and carcinogen, there is a major concern that smoking may adversely affect male reproductive health. For men the smoking is a risk factor for the development of a variety of urological diseases, although the exact mechanism of action is still unknown. Furthermore, when we look at the reproductive issues, we found that zinc is essential for spermatogenesis as a cofactor of metalloenzyme involved in the transcription of DNA, the expression of steroid receptors and protein synthesis. In addition, zinc presents anti-oxidant and anti-apoptotic actions. Based on this information, the purpose of this study was to examine the role of zinc on fertility and testicular function in rats exposed to tobacco. Male Wistar rats were divided into four groups (10/group): Control (G1), Cigarette smoke (G2), Zinc (G3: Zn 20mg/kgdaily by gavages) and Zinc/cigarette (G4). The treatment was applied during eight weeks. After finishing the treatment, the following parameters were analyzed: body weight, wet weight of the reproductive organs and the adrenal gland; plasma testosterone concentration, testicular function (seminal analysis and daily production of spermatozoa); fertility and sexual behavior. The pharmacological responses of male accessory genital smooth muscle (vas deferens and seminal vesicle) to autonomic drugs and DNA damage in the spermatozoa were also evaluated. The results were compared by non-parametric analysis of variance, for model with two factors, and the test for multiple comparisons of Tukey was applied when necessary , p<0.05. The exposure to cigarette smoke decreased the concentration of testosterone parallel to a decrease in the concentration, morphology, and motility of spermatozoa. As a result of these... (Complete abstract click electronic access below)
About one-third of the world's male population smokes tobacco daily. Considering the larger number of men worldwide who smoke, and that cigarette is a known somatic cells mutagen and carcinogen, there is a major concern that smoking may adversely affect male reproductive health. For men the smoking is a risk factor for the development of a variety of urological diseases, although the exact mechanism of action is still unknown. Furthermore, when we look at the reproductive issues, we found that zinc is essential for spermatogenesis as a cofactor of metalloenzyme involved in the transcription of DNA, the expression of steroid receptors and protein synthesis. In addition, zinc presents anti-oxidant and anti-apoptotic actions. Based on this information, the purpose of this study was to examine the role of zinc on fertility and testicular function in rats exposed to tobacco. Male Wistar rats were divided into four groups (10/group): Control (G1), Cigarette smoke (G2), Zinc (G3: Zn 20mg/kgdaily by gavages) and Zinc/cigarette (G4). The treatment was applied during eight weeks. After finishing the treatment, the following parameters were analyzed: body weight, wet weight of the reproductive organs and the adrenal gland; plasma testosterone concentration, testicular function (seminal analysis and daily production of spermatozoa); fertility and sexual behavior. The pharmacological responses of male accessory genital smooth muscle (vas deferens and seminal vesicle) to autonomic drugs and DNA damage in the spermatozoa were also evaluated. The results were compared by non-parametric analysis of variance, for model with two factors, and the test for multiple comparisons of Tukey was applied when necessary , p<0.05. The exposure to cigarette smoke decreased the concentration of testosterone parallel to a decrease in the concentration, morphology, and motility of spermatozoa. As a result of these... (Complete abstract click electronic access below)
Descrição
Palavras-chave
Fumo - Vicio, Fecundidade, Zinco, Tobacco, Fertility, Testicular function
Como citar
GARCIA, Patrícia Carvalho. Papel do zinco sobe a fertilidade e função testicular de ratos expostos ao tabaco. 2009. 92 f. Tese (doutorado) - Universidade Estadual Paulista, Faculdade de Medicina de Botucatu, 2009.