Weaver C J, Johnson M D
Department of Physiology, West Virginia University, Morgantown 26506.
Am J Physiol. 1990 Sep;259(3 Pt 1):E432-6. doi: 10.1152/ajpendo.1990.259.3.E432.
Reduction of renal perfusion is followed by increases in plasma renin activity (PRA) and arterial pressure. The present experiments were designed to determine if an opiate antagonist would alter pressor or renin responses to acute reduction of renal arterial pressure (RAP) in anesthetized rats. Male Sprague-Dawley rats were anesthetized with Inactin, and an adjustable constrictor device was placed around the abdominal aorta proximal to the renal arteries. One-half of the animals were pretreated with the opiate antagonist naloxone (2 mg/kg iv), and the other one-half were pretreated with saline vehicle. The abdominal aorta was then constricted to reduce RAP by 25% (measured as femoral arterial pressure) in one-half of the animals in each pretreatment group. Compared with vehicle pretreatment, naloxone pretreatment did not alter the PRA response to aortic constriction; however, naloxone did attenuate the pressor response. We conclude that 1) the PRA response to acute reduction of renal arterial pressure is not dependent on an opiate mechanism in the rat, and 2) attenuation of the pressor response to aortic constriction by naloxone in intact rats is not secondary to a suppression of the PRA response.
肾灌注减少后，血浆肾素活性（PRA）和动脉压会升高。本实验旨在确定阿片拮抗剂是否会改变麻醉大鼠对肾动脉压（RAP）急性降低的升压或肾素反应。雄性Sprague-Dawley大鼠用氯胺酮麻醉，在肾动脉近端的腹主动脉周围放置一个可调节的收缩装置。将动物的一半用阿片拮抗剂纳洛酮（2mg/kg静脉注射）预处理，另一半用生理盐水载体预处理。然后在每个预处理组的一半动物中收缩腹主动脉，使RAP降低25%（以股动脉压测量）。与载体预处理相比，纳洛酮预处理并未改变对主动脉收缩的PRA反应；然而，纳洛酮确实减弱了升压反应。我们得出结论：1）大鼠对肾动脉压急性降低的PRA反应不依赖于阿片机制；2）纳洛酮对完整大鼠主动脉收缩升压反应的减弱并非继发于对PRA反应的抑制。
