Shoji M, Share L, Crofton J T
Department of Physiology and Biophysics, University of Tennessee, Memphis.
Neuroendocrinology. 1989 Sep;50(3):327-33. doi: 10.1159/000125241.
We have studied in conscious unrestrained rats the role of angiotensin II receptors in the paraventricular nucleus (PVN) in the control of vasopressin secretion under basal conditions and after 24 h of water deprivation. In euhydrated rats, the microinjection rostral to the PVN of 1 and 5 ng of angiotensin II produced a transient, dose-dependent increase in the plasma vasopressin concentration. There was also a transient, but not dose-dependent, rise in mean arterial blood pressure (MABP), without a change in heart rate. However, the microinjection of angiotensin II into the PVN and sites caudal to it was without effect on the measured variables. In dehydrated rats, on the other hand, microinjection of 5 ng angiotensin II, both into the PVN and rostral to it, resulted in a prolonged increase in the plasma vasopressin concentration. The response from the rostral site was more rapid and was associated with an increased MABP. These findings suggest that angiotensin II receptors rostral to the PVN may participate in the control of vasopressin release in both euhydrated and dehydrated states, whereas angiotensin II receptors in the PVN are effective only following dehydration.
我们在清醒自由活动的大鼠中研究了室旁核（PVN）中血管紧张素II受体在基础条件下以及禁水24小时后对血管加压素分泌控制中的作用。在水分正常的大鼠中，向PVN嘴侧微量注射1纳克和5纳克血管紧张素II可使血浆血管加压素浓度产生短暂的、剂量依赖性升高。平均动脉血压（MABP）也有短暂但非剂量依赖性的升高，心率无变化。然而，向PVN及其尾侧部位微量注射血管紧张素II对所测变量无影响。另一方面，在脱水大鼠中，向PVN及其嘴侧注射5纳克血管紧张素II，可使血浆血管加压素浓度持续升高。嘴侧部位的反应更快，且与MABP升高有关。这些发现表明，PVN嘴侧的血管紧张素II受体可能在水分正常和脱水状态下均参与血管加压素释放的控制，而PVN中的血管紧张素II受体仅在脱水后才有效。
