Fan L, Archambault D, Chavez S, Aljabari A W, Quillen E W
Department of Obstetrics and Gynecology, McGill University, Montreal, Quebec, Canada.
Am J Physiol. 1994 Mar;266(3 Pt 2):R668-73. doi: 10.1152/ajpregu.1994.266.3.R668.
To investigate the role of the renal nerves in the control of renin secretion during pregnancy, we prepared sheep with one denervated kidney, bilateral renal vein catheters, and an inflatable aortic occluder. The renin secretory responses to step reductions of renal perfusion pressure (RPP) of the innervated and denervated kidneys were compared in eight nonpregnant and nine pregnant (115-130 days gestation) sheep in a normal conscious state. Nonpregnant sheep had average basal levels of mean arterial pressure (MAP) of 91 +/- 3 mmHg, plasma renin activities (PRA) of 2.3 +/- 0.4 ng ANG I.ml-1.3 h-1, and plasma angiotensin (ANG) concentrations of 8.4 +/- 1.1 pg/ml. Pregnant sheep had reduced levels (P < 0.01) of MAP (76 +/- 3 mmHg) but elevated levels of PRA (3.8 +/- 0.4 ng ANG I.ml-1.h 3-1; P < 0.5) and ANG II (12.0 +/- 1.6 pg/ml; P = 0.08). Four successively reduced levels of RPP were observed for 15 min each in both groups of sheep. In both groups, RPP was reduced to a final level of 51 +/- 2 mmHg. The renal venous-arterial difference of PRA (v-aPRA) from the innervated kidneys was increased as RPP was reduced. However, there was little response of v-aPRA to RPP in denervated kidneys. In nonpregnant sheep, the relationship between RPP and renin secretion rate was characterized by an initially slow phase, over which small reductions of RPP resulted in small increases in renin secretion. As RPP fell, this relationship became progressively steeper in nonpregnant ewes.(ABSTRACT TRUNCATED AT 250 WORDS)
为研究肾神经在孕期肾素分泌调控中的作用，我们对绵羊进行如下准备：一侧肾去神经，双侧肾静脉置管，并安置可充气的主动脉阻断器。在正常清醒状态下，比较了8只非孕绵羊和9只孕羊（妊娠115 - 130天）中，受神经支配和去神经支配的肾脏对肾灌注压（RPP）逐步降低的肾素分泌反应。非孕绵羊平均动脉压（MAP）基础水平为91±3 mmHg，血浆肾素活性（PRA）为2.3±0.4 ng ANG I·ml⁻¹·3 h⁻¹，血浆血管紧张素（ANG）浓度为8.4±1.1 pg/ml。孕羊MAP水平降低（P<0.01）至76±3 mmHg，但PRA（3.8±0.4 ng ANG I·ml⁻¹·h⁻¹；P<0.5）和ANG II（12.0±1.6 pg/ml；P = 0.08）水平升高。两组绵羊均观察到RPP依次降低4个水平，每个水平持续15分钟。两组中，RPP均降至最终水平51±2 mmHg。随着RPP降低，受神经支配肾脏的肾静脉 - 动脉PRA差值（v - aPRA）增加。然而，去神经支配的肾脏中v - aPRA对RPP几乎无反应。在非孕绵羊中，RPP与肾素分泌率的关系特征为初始阶段缓慢，在此阶段RPP的小幅降低导致肾素分泌的小幅增加。随着RPP下降，这种关系在非孕母羊中逐渐变得更陡峭。（摘要截断于250字）
