Influencia do ciclo estral sobre as respostas hormonais de ratas submetidas a estresse

AUTOR(ES)
DATA DE PUBLICAÇÃO

1998

RESUMO

Right atria isolated from female rats submitted to three footshoek or swimming sessions showed changes on sensitivity to eateeholamines, when the stress sessions were applied during estrus, metestrus and diestrus (Diestrus Group), without changes when they were applied at diestrus, proestrus and estrus (Estrus Group). The aim of this work was to analyse the serie levels of eortieosterone, progesterone and estradiol from rats submitted to the same protocols to evaluate the influence of the estrous eyc1e on the hormonal responses to footshoek and swimming stress, and to verify the relationship between these hormonal responses and the development of changes on the sensitivity to eateeholamines in right atria from stressed female rats sacrificed at diestrus, but not at estrus. We observed an increase of eortieosterone and progesterone in the serum from rats submitted to footshoek stress, without changes on the levels of estradiol, at both groups Diestrus and Estrus. However, swimming stress induced higher increase in eortieosterone levels from rats sacrificed at diestrus than at estrus. In both groups, there were similar increases on progesterone levels. After swimming stress, female rats sacrificed at diestrus didn t show any variation in the serie levels of estradiol. On the other hand, estradiol serie levels increased at Estrus group, without change at Diestrus group. The time-course of the changes in the serie levels of eortieosterone and progesterone were not different between Diestrus and Estrus group, after footshoek stress. However the levels of estradiol decreased after the first footsehoek session in rats from the Diestrus group. In rats from the Estrus group, footshoek stress didn t indueed any changes in the levels of this hormone, except for an increase in the moming of the second stress session. However, this increase probably was induced by the estrous eyc1e sinee the animals were at postures phase. We also nalyzed the anxiety levels of control female rats. Anxiety levels were lower during proestrus than during distrust. We suggest that the increase on cortieosterone and progesterone levels with a decrease on estradiollevels could induce the changes on sensitivity to eateeholamines in right atria from female rats submitted to foot shock stress and sacrificed at diestrus. On the other hand, these changes are prevented in stressed female rats sacrificed at estrus when the increase on corticosterone and progesterone levels occurred without changes on estradiollevels, and during proestrus, when anxiety levels are lower

ASSUNTO(S)

rato ciclo sexual

ACESSO AO ARTIGO

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