Navegando por Palavras-chave "Diferença entre sexos"

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    Efeitos da privação de sono sobre parâmetros cardiovasculares em ratos machos e fêmeas
    (Universidade Federal de São Paulo (UNIFESP), 2011-06-29) Tenório, Neuli Maria [UNIFESP]; Andersen, Monica Levy [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    Curtailment of sleep time is a characteristic of modern society, and the reciprocal association between duration of sleep and weight gain has been under scrutiny as of late. The consequences of such factors upon the cardiovascular system remain to be fully elucidated, particularly along a full life span. Moreover, the consequences of sleep deprivation may also be influenced by the gender. The current study thus purported to examine the impact of acute sleep deprivation associated to obesity in female Zucker rats of different ages (Paper 1) and to compare the effects of paradoxical sleep deprivation (PSD) and chronic sleep restriction (SR) in male and female eutrophic rats (Paper 2) upon the cardiovascular (Papers 1 and 2) and hormonal (Paper 2 ) parameters. For the experiments described in Paper 1 lean and obese female Zucker rats 3, 6, and 15 months old were distributed into either control groups (CTRL, homecage) or sleep deprived (SD). For the experiments of Paper 2 adult female and male Wistar rats were distributed in either control groups (CTRL, home-cage) or in Paradoxical Sleep Deprivation for 96h groups (PSD-96h) or Sleep Restriction for 21 days groups (SR 21 days). In both experiments the subjects were anesthetized according to respective SD protocol or equivalent time in the CTRL groups, after which a catheter was placed in their femoral artery and vein. The baroreflex sensibility index was measured by means of phenilephrine (bradicardiac response) and sodium nitroprussiate (taquicardiac response). For the experiments conducted for Paper 2 a different group of subjects was used for blood harvesting to assess the concentrations of adrenocorticotrophic hormone (ACTH). In Paper 1 we observed that obesity resulted in dysfunctional taquicardia in subjects from 3 months of age and on. At 6 and 15 months of age the bradicardiac and taquicardiac response were significantly smaller in obese subjects when compared to respective lean groups. At 15 months of age the interaction between obesity, SD and age caused the greatest consequences in the cardiovascular system as arterial. Results of Paper 2 show that the average arterial pressure was significantly higher in the SR group when compared to the CTRL group in both genders. In females, cardiac frequency was significantly higher after PSD when compared to respective controls. The SR protocol attenuated the vagal baroreflex response similarly in males and females. The sympathetic baroreflex response was attenuated in the PSD and SR groups, but in females this parameter was affected only after PSD. No significant difference in relation to gender was observed in any of the cardiovascular parameters. PSD did increase ACTH concentrations significantly when compared to controls of both genders. The body of results yielded by both studies suggests that different periods of lost sleep lead to specific consequences in cardiovascular and hormonal parameters, and such effects were similar in male and female rat subjects.