Danesh S, Walker L A
Department of Pharmacology, School of Pharmacy, University of Mississippi, University.
J Pharmacol Exp Ther. 1988 Feb;244(2):640-5.
Systemic administration of morphine in rats produces an anti-natriuretic effect that is at least partially dependent on renal nerves. The present studies were carried out in order to assess the renal response to central administration of morphine. Male Sprague-Dawley rats were surgically prepared with arterial, venous and bladder cannulas. In addition, a guide cannula was placed into the lateral ventrical and secured to the surface of the skull. Experiments were carried out at least 3 days after surgery. Renal clearance measurements were 30 min each. After a basal period, morphine sulfate (4 micrograms/4 microliters) or vehicle was injected into the lateral cerebral ventricle. Two clearance measurements were obtained, followed by central administration of naloxone HCl (4 micrograms/4 microliters) or vehicle and two more clearance periods. Morphine administration had no effect on blood pressure or heart rate but caused a sharp reduction in sodium excretion (3200 +/- 958 vs 970 +/- 158 nEq/100 g/min in period 5; P less than .05). This response was reversed by the addition of naloxone (3280 +/- 583 nEq/100 g/min in period 5; P less than .05). Furthermore, morphine had no effect on renal plasma flow and glomerular filtration rate. Naloxone increased the renal plasma flow and glomerular filtration rate in morphine-treated rats, whereas it had no effect in controls. It is concluded that central administration of morphine in conscious rats enhances renal tubular sodium reabsorption by an opiate receptor-dependent mechanism.
给大鼠全身注射吗啡会产生抗利尿钠作用，这种作用至少部分依赖于肾神经。进行本研究是为了评估大鼠对中枢注射吗啡的肾脏反应。雄性Sprague-Dawley大鼠通过手术植入动脉、静脉和膀胱插管。此外，将一根引导插管插入侧脑室并固定在颅骨表面。实验在手术后至少3天进行。每次肾清除率测量为30分钟。在基础期后，将硫酸吗啡（4微克/4微升）或赋形剂注入侧脑室。获得两次清除率测量值，随后中枢注射盐酸纳洛酮（4微克/4微升）或赋形剂，并再进行两个清除期。注射吗啡对血压或心率没有影响，但导致钠排泄急剧减少（第5期为3200±958对970±158纳当量/100克/分钟；P＜0.05）。加入纳洛酮后这种反应逆转（第5期为3280±583纳当量/100克/分钟；P＜0.05）。此外，吗啡对肾血浆流量和肾小球滤过率没有影响。纳洛酮增加了吗啡处理大鼠的肾血浆流量和肾小球滤过率，而对对照组没有影响。结论是，对清醒大鼠中枢注射吗啡通过一种阿片受体依赖性机制增强肾小管钠重吸收。
