Leite, C. M.
Anselmo-Franci, J. A.
Total Authors: 4
 Univ Sao Paulo, Fac Med Ribeirao Preto, Dept Fisiol, BR-14040904 Sao Paulo - Brazil
 Univ Sao Paulo, Fac Odontol Ribeirao Preto, Dept Fisiol Morfol & Estomatol, Neuroendocrinol Lab, BR-14040904 Sao Paulo - Brazil
 Univ Sao Paulo, Fac Ciencias Farmaceut Ribeirao Preto, BR-14040904 Sao Paulo - Brazil
Total Affiliations: 3
STRESS-THE INTERNATIONAL JOURNAL ON THE BIOLOGY OF STRESS;
Web of Science Citations:
Adrenal progesterone secretion increases along with corticosterone in response to stress in male and female rats to modulate some stress responses. Here we investigated the role of sex steroids in sex differences in the progesterone response to 60 min of restraint stress in adult male and female rats. Comparisons between males and females in the progesterone response were evaluated in parallel with corticosterone responses. From day 5 to 7 after gonadectomy, female and male rats were treated with estradiol or testosterone, respectively (OVX-E and ORCH-T groups), or oil (OVX and ORCH groups). Female rats in proestrus, intact and 7 d adrenalectomized (ADX) male rats were also studied. At 10: 00 h, blood samples were withdrawn via an implanted jugular cannula before (-5 min), during (15, 30, 45, 60 min) and after (90 and 120 min) restraint stress to measure plasma progesterone and corticosterone concentrations by radioimmunoassay. Intact male and proestrus female rats exhibited similar progesterone responses to stress. Gonadectomy did not alter the amount of progesterone secreted during stress in female rats but decreased secretion in male rats. Unlike corticosterone, the progesterone response to stress in females was not influenced by estradiol. In males, testosterone replacement attenuated the progesterone and corticosterone responses to stress. Basal secretion of progesterone among intact, ORCH and ADX males was similar, but ADX-stressed rats secreted little progesterone. Hence, the gonads differently modulate adrenal progesterone and corticosterone responses to stress in female and male rats. The ovaries enhance corticosterone but not progesterone secretion, while the testes stimulate progesterone but not corticosterone secretion. (AU)