He X R, Shi L, Wang W H, Yao T
Department of Physiology, Shanghai Medical University.
Sheng Li Xue Bao. 1992 Jun;44(3):215-21.
The experiments were performed in rats anaesthetized with alpha-chloralose and urethane. Intracerebroventricular administration of hypertonic saline (icv. HS) resulted in an increase in renal plasma flow rate, glomerular filtration rate, urine flow rate, urinary sodium excretion, urinary potassium excretion, and osmolar clearance, and a decrease in free water clearance. These responses were abolished in hypophysectomized rats, but were not significantly affected by intravenous injection of vasopressin (VP) receptor (V1 and V2) antagonist. The urinary dopamine (DA) excretion did not change significantly after icv. HS. Moreover, administration of benserazide, an inhibitor of the enzyme L-aromatic amino acid decarboxylase that converts L-dopa to DA, did not attenuate the diuresis and natriuresis induced by icv. HS. These results suggest that the renal responses upon stimulation of the brain osmoreceptor are dependent on the integrity of the hypophysis, while the VP and DA are not essential to these renal responses. The hypophysial factors responsible for the icv. HS-induced renal responses remain to be explored.
实验在使用α-氯醛糖和乌拉坦麻醉的大鼠身上进行。脑室内注射高渗盐水（icv. HS）导致肾血浆流速、肾小球滤过率、尿流率、尿钠排泄、尿钾排泄和渗透清除率增加，而自由水清除率降低。这些反应在垂体切除的大鼠中消失，但静脉注射血管加压素（VP）受体（V1和V2）拮抗剂对其无显著影响。icv. HS后尿多巴胺（DA）排泄无显著变化。此外，给予苄丝肼（一种将左旋多巴转化为DA的L-芳香族氨基酸脱羧酶抑制剂）并未减弱icv. HS诱导的利尿和利钠作用。这些结果表明，刺激脑渗透压感受器时的肾脏反应依赖于垂体的完整性，而VP和DA对这些肾脏反应并非必不可少。负责icv. HS诱导的肾脏反应的垂体因子仍有待探索。
