Wu Y, Du J Z
Division of Neurobiology and Physiology, College of Sciences (Yuquan Campus), Zhejiang University, Hangzhou 310027, China.
Acta Pharmacol Sin. 2000 Nov;21(11):1035-8.
To investigate the effects of angiotensin II (Ang II) on corticotropin-releasing hormone (CRH) and argipressin (AVP) release from median eminence (ME) of hypothalamus during acute hypoxia in rats.
Simulated hypoxia was performed in a hypobaric chamber. CRH and AVP were determined by radioimmunoassay (RIA). Plasma corticosterone concentration was measured by fluorometry.
Ang II did not influence CRH release induced by hypoxia [CRH in group pretreated with Ang II (16 +/- 8) ng/ME vs control (15 +/- 4) ng/ME, both exposed to hypoxia with simulated altitude 7 km (8.2% O2)]. Ang II enhanced AVP release, from (5.7 +/- 1.6) ng/ME in control decreasing to (2.6 +/- 1.2) ng/ME (P < 0.05), meanwhile plasma corticosterone concentration was also increased markedly, from (356 +/- 58) in control to (536 +/- 134) micrograms/L plasma (P < 0.05), which was partly abolished by administration of AVP antiserum.
Ang II might stimulate hypothalamo-pituitary-adrenal axis (HPA) through activating AVP but not CRH release during acute hypoxia.
研究血管紧张素II（Ang II）对大鼠急性缺氧时下丘脑正中隆起（ME）促肾上腺皮质激素释放激素（CRH）和精氨酸加压素（AVP）释放的影响。
在低压舱内进行模拟缺氧。采用放射免疫分析法（RIA）测定CRH和AVP。用荧光法测量血浆皮质酮浓度。
Ang II不影响缺氧诱导的CRH释放[在海拔7 km（氧气含量8.2%）模拟缺氧条件下，Ang II预处理组的CRH为（16±8）ng/ME，对照组为（15±4）ng/ME]。Ang II增强AVP释放，从对照组的（5.7±1.6）ng/ME降至（2.6±1.2）ng/ME（P<0.05），同时血浆皮质酮浓度也显著升高，从对照组的（356±58）μg/L血浆升至（536±134）μg/L血浆（P<0.05），给予AVP抗血清可部分消除这种升高。
在急性缺氧期间，Ang II可能通过激活AVP而非CRH释放来刺激下丘脑-垂体-肾上腺轴（HPA）。
