Effect of estrogen on cardiovascular responses to psychological stress in rats

雌激素对大鼠心理应激心血管反应的影响

基本信息

批准号：
13670064
负责人：
MORIMOTO Keiko
金额：
$ 2.3万
依托单位：
Nara Women's University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2002
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13670064/
关键词：
psychological stress estrogen blood pressure Corticotrophin releasing hormone (CRH)plasma norepinephrine plasma epinephrine telemetry system heart rate Corticotrophin releasing hormone(CRH)脳室内投与 α-helical CRH エストロゲン補充性差循環反応

项目摘要

Estrogens are reported to have cardiovascular protective effects, but the mechanisms underlying these effects are not well defined. We investigated the sex difference in stress-induced cardiovascular responses and the effect of estrogen on these responses in free-moving adult rats. Furthermore, we assessed the central role of estrogen on the effect of corticotrophin-releasing hormone (CRH) in stress-induced cardiovascular responses.Four groups of rats, which consisted of male (M), normal female (NF), ovariectomized+placebo-treated (P) and ovariectomized+estrogen-treated (E) groups, were used in this experiment.1. Psychological stress was induced by cage-switch stress. After rats were placed in the novel environment, blood pressure and heart rate significantly increased. Blood pressure elevation was attenuated significantly in the NF group compared with the M group. Ovariectomy diminished the sex difference of blood pressure response to the stress.2. In the M group blood pressure elevat … More ion during cage-switch stress, which was repeated 60 min daily, was weakened on the 2nd and the 3rd days compared with the 1st day, but not in the NF group.2. The blood pressure responses were suppressed significantly in the E group compared with the P group during cage-switch and restraint stress. The plasma norepinephrine response induced by cage-switch stress was attenuated significantly in the E group.3. In unstressed NF, P and E group rats, the intracerebroventricular (I.C.V.) injection of CRF-41 (10 μg) increased blood pressure and heart rate. However, there were no significant differences between 3 groups.4. The I.C.V.injection of a-helical CRH (9-41), a CRH-41 receptor antagonist, did not attenuated the stress-induced hypertension in the 3 groups of female rats.These results suggest that estrogen may influence blood pressure regulation during stress in suppressing the activation of a sympathetic nervous tone in female rat. The mechanisms responsible for the greater resistance to these stresses in the NF and E group should be investigated further. Less

据报道，雌激素具有心血管保护作用，但这些作用的机制尚未明确，我们研究了压力引起的心血管反应的性别差异以及雌激素对自由活动的成年大鼠的影响。雌激素对促肾上腺皮质激素释放激素（CRH）在应激诱导的心血管反应中的作用的核心作用。四组大鼠，包括雄性（M）、正常雌性（NF）、卵巢切除+安慰剂治疗（P）和本实验采用去势+雌激素治疗组。 1．转笼应激引起的心理应激，将大鼠置于新环境后，血压和心率升高明显减弱。与 M 组相比，NF 组显着减少了血压对应激反应的性别差异。2. 重复 60 次后，M 组血压升高。分钟每天，与第1天相比，第2天和第3天减弱，但在NF组中没有减弱。2．与P组相比，E组在转笼和束缚应激期间血压反应被显着抑制。 E组大鼠笼开关应激引起的血浆去甲肾上腺素反应明显减弱。3． (I.C.V.) 注射 CRF-41 (10 μg) 会增加血压和心率，但 3 组之间没有显着差异。 4. I.C.V. 注射 a-helical CRH (9-41)，一种 CRH-41。受体拮抗剂，并没有减轻 3 组雌性大鼠的应激性高血压。这些结果表明，雌激素可能通过抑制交感神经张力的激活来影响应激期间的血压调节。应该进一步研究 NF 组和 E 组雌性大鼠对这些应激具有更强抵抗力的机制。