Krasney J A, Carroll M, Krasney E, Iwamoto J, Claybaugh J R, Hong S K
Department of Physiology, School of Medicine and Biomedical Sciences, State University of New York, Buffalo 14214.
Am J Physiol. 1991 Jul;261(1 Pt 2):R188-97. doi: 10.1152/ajpregu.1991.261.1.R188.
Renal responses to low doses of atrial natriuretic peptide (ANP) may be potentiated during water immersion-induced central hypervolemia. To test this hypothesis, ANP was infused in awake dogs in doses of 0, 5, and 25 ng.kg-1.min-1 either when the dogs were in air or during head-out water immersion (WI) under thermoneutral conditions (37 degrees C). In general, there were greater diuretic (V) and natriuretic responses (UNaV) at the same level of plasma ANP in WI, with the slopes (or sensitivities) of V and UNaV in relation to plasma ANP levels being significantly increased during WI. Plasma renin activity decreased only during WI and was significantly correlated with both V and UNaV only during WI. Plasma and urinary arginine vasopressin levels were unchanged during WI. Infusion of ANP prevented the usual decline of hematocrit that occurs during WI. These results support the view that the renal sensitivity to ANP is augmented during the plasma volume expansion of WI. In addition, ANP may attenuate the transcapillary fluid shift that occurs during WI.
在水浸诱导的中枢性血容量过多期间，肾脏对低剂量心房利钠肽（ANP）的反应可能会增强。为了验证这一假设，在清醒犬处于空气中或在热中性条件（37摄氏度）下进行头露出水面的水浸（WI）时，分别以0、5和25 ng·kg-1·min-1的剂量输注ANP。一般来说，在WI时，相同血浆ANP水平下的利尿反应（V）和利钠反应（UNaV）更大，WI期间V和UNaV相对于血浆ANP水平的斜率（或敏感性）显著增加。血浆肾素活性仅在WI期间降低，且仅在WI期间与V和UNaV显著相关。WI期间血浆和尿中精氨酸加压素水平无变化。输注ANP可防止WI期间通常出现的血细胞比容下降。这些结果支持这样一种观点，即在WI引起的血浆容量扩张期间，肾脏对ANP的敏感性增强。此外，ANP可能会减弱WI期间发生的跨毛细血管液体转移。
