Aguilera G, Young W S, Kiss A, Bathia A
Section on Endocrine Physiology, National Institute of Child Health and Human Development, NIH, Bethesda, MD 20892, USA.
Neuroendocrinology. 1995 Apr;61(4):437-44. doi: 10.1159/000126866.
The possible role of angiotensin II (AII) in the control of the hypothalamic-pituitary-adrenal (HPA) axis was studied in the rat by examining the regulation and cellular localization of AII receptors in the paraventricular nucleus (PVN) of the hypothalamus and the effect of AII on corticotropin-releasing hormone (CRH) and vasopressin (VP) mRNA levels. In situ hybridization studies using cRNA 35S-labelled probes showed that while type 1 AII receptor (AT1) mRNA levels were high in the periventricular and parvicellular pars of the PVN, only very low levels were present in the magnocellular pars. A similar distribution of AT1 receptor binding in the periventricular, parvicellular and magnocellular divisions of the PVN was observed in autoradiographic studies in hypothalamic sections labelled with 125I[Sar1,Ile8]AII. In addition, AII receptor binding was clearly evident in nerve fibers adjacent to the PVN. Double-labelling hybridization using digoxigenin-labelled CRH, VP and oxytocin probes and 35S-labelled AT1 receptor cRNA probes showed AT1 receptor mRNA in cells stained for CRH mRNA, but not in VP or oxytocin cells. Four hours after a single intracerebroventricular (i.c.v.) injection of 50 ng AII in conscious rats, CRH mRNA levels in the PVN were increased by 43%, similar to the increases observed following acute stress by intraperitoneal (i.p.) injection of 1.5 M NaCl (76%). On the other hand, while i.p. hypertonic saline injection increased VP mRNA levels by 29% in the PVN and by 32% in the supraoptic nucleus, i.c.v. AII injection had no significant effect.(ABSTRACT TRUNCATED AT 250 WORDS)
通过检测下丘脑室旁核（PVN）中血管紧张素II（AII）受体的调节和细胞定位以及AII对促肾上腺皮质激素释放激素（CRH）和血管加压素（VP）mRNA水平的影响，研究了AII在大鼠下丘脑 - 垂体 - 肾上腺（HPA）轴调控中的可能作用。使用cRNA 35S标记探针的原位杂交研究表明，虽然PVN的室周部和小细胞部中1型AII受体（AT1）mRNA水平较高，但大细胞部中仅存在极低水平。在用125I[Sar1，Ile8]AII标记的下丘脑切片的放射自显影研究中，观察到PVN的室周、小细胞和大细胞区中AT1受体结合的类似分布。此外，在PVN相邻的神经纤维中AII受体结合明显可见。使用地高辛标记的CRH、VP和催产素探针以及35S标记的AT1受体cRNA探针进行的双重标记杂交显示，AT1受体mRNA存在于CRH mRNA染色的细胞中，但不存在于VP或催产素细胞中。在清醒大鼠单次脑室内（i.c.v.）注射50 ng AII后4小时，PVN中CRH mRNA水平增加了43%，类似于腹腔内（i.p.）注射1.5 M NaCl急性应激后观察到的增加（76%）。另一方面，虽然腹腔内注射高渗盐水使PVN中VP mRNA水平增加了29%，视上核中增加了32%，但脑室内注射AII没有显著影响。（摘要截于250字）
