Junkergård J
Department of Physiology, Faculty of Veterinary Medicine, Swedish University of Agricultural Sciences, Uppsala.
Acta Physiol Scand. 1990 Jan;138(1):67-73. doi: 10.1111/j.1748-1716.1990.tb08813.x.
Previous evidence for cerebral sodium/angiotensin interaction concerning centrally mediated effects of angiotensin II (AII) provided the incitement to compare in goats effects of i.v. AII during sodium repletion (SR) with those obtained during mild sodium depletion (SD). The experiments were performed in the euhydrated as well as hyperhydrated animals, and AII was infused for 10 min at 40 pmol kg-1 min-1. It was confirmed that SD is associated with elevated plasma aldosterone concentration (PA) and (as regards aldosterone secretion) a sensitization of the adrenal cortex. In contrast to PA, the plasma cortisol (PC) response to i.v. AII was significantly reduced during SD, apparently due to diminished cerebral sensitivity to circulating AII. A similar SD-associated attenuation was observed during euhydration as regards release of arginine vasopressin (AVP) in response to i.v. AII, and during hyperhydration as regards the antidiuretic effect of the octapeptide. It was confirmed that the pressor effect of i.v. AII becomes markedly reduced during SD. However, in spite of this, the associated bradycardia remained the same during SR and SD, suggesting that SD also attenuated the centrally mediated chronotropic effect of AII.
先前有关脑钠/血管紧张素相互作用（涉及血管紧张素II（AII）的中枢介导作用）的证据促使人们在山羊中比较静脉注射AII在钠补充（SR）期间与轻度钠缺乏（SD）期间的效果。实验在水合正常以及水合过多的动物中进行，以40 pmol kg-1 min-1的速率静脉输注AII 10分钟。已证实，SD与血浆醛固酮浓度（PA）升高以及（就醛固酮分泌而言）肾上腺皮质的敏感性增加有关。与PA相反，在SD期间，静脉注射AII后血浆皮质醇（PC）反应显著降低，这显然是由于大脑对循环AII的敏感性降低所致。在水合正常期间，静脉注射AII后精氨酸加压素（AVP）的释放以及在水合过多期间八肽的抗利尿作用方面，观察到了类似的与SD相关的减弱。已证实，静脉注射AII的升压作用在SD期间明显减弱。然而，尽管如此，SR和SD期间相关的心动过缓保持不变，这表明SD也减弱了AII的中枢介导的变时作用。
