Johnson M D, Cavender R K
Department of Physiology, West Virginia University Health Sciences Center, Morgantown 26506.
Am J Physiol. 1992 Jan;262(1 Pt 1):E100-4. doi: 10.1152/ajpendo.1992.262.1.E100.
The present experiments were designed to determine whether blockade of endogenous opiate receptors with naloxone would suppress renin release induced by circulating epinephrine or by reductions of renal perfusion pressure. In the first series of experiments, anesthetized dogs were prepared with a flow probe around the left renal artery and a catheter in the left renal vein, permitting measurement of renin secretion before, during, and after 15-min infusions of epinephrine (50 ng.kg-1.min-1 iv). The epinephrine infusions were conducted either before or after blockade of opiate receptors with naloxone (1 mg/kg iv). Naloxone failed to alter the renin secretory response to intravenous epinephrine infusion. In a second series of experiments, anesthetized dogs were uninephrectomized and prepared with a constrictor cuff around the left renal artery and a renal arterial catheter distal to the cuff. After control measurements of renal perfusion pressure and plasma renin activity (PRA), the cuff was constricted at 15-min intervals to produce controlled stepwise reductions of renal perfusion pressure ranging from 15 to 90 mmHg. One-half of the animals was pretreated with naloxone (1 mg/kg iv). Naloxone pretreatment had no effect on the PRA response to reduced renal perfusion pressure at any pressure. The data fail to support the hypothesis that endogenous opioid peptides are modulators in the control of renin release.
本实验旨在确定用纳洛酮阻断内源性阿片受体是否会抑制循环肾上腺素或肾灌注压降低所诱导的肾素释放。在第一组实验中，对麻醉的狗进行如下准备：在左肾动脉周围放置流量探头，在左肾静脉插入导管，以便在静脉输注肾上腺素（50 ng·kg-1·min-1）15分钟的过程中及前后测量肾素分泌。在使用纳洛酮（1 mg/kg静脉注射）阻断阿片受体之前或之后进行肾上腺素输注。纳洛酮未能改变静脉输注肾上腺素时的肾素分泌反应。在第二组实验中，对麻醉的狗进行单侧肾切除，并在左肾动脉周围放置收缩套囊，在套囊远端插入肾动脉导管。在对肾灌注压和血浆肾素活性（PRA）进行对照测量后，每隔15分钟收缩一次套囊，使肾灌注压逐步控制性降低，范围为15至90 mmHg。一半的动物预先用纳洛酮（1 mg/kg静脉注射）处理。纳洛酮预处理对任何压力下肾灌注压降低时的PRA反应均无影响。这些数据不支持内源性阿片肽是肾素释放控制中的调节因子这一假说。
