Spencer R L, Deupree D, Hsiao S, Mosberg H I, Hruby V, Burks T F, Porreca F
Pharmacol Biochem Behav. 1986 Jul;25(1):77-82. doi: 10.1016/0091-3057(86)90233-9.
The effects of intracerebroventricular injection of mu (morphine), kappa (dynorphin-(1-13), ethylketocyclazocine, and U50,488H), and delta ([D-Pen2, D-Pen5]enkephalin) opioid agonists on water intake of 14 hr water deprived rats was studied. All agonists caused a dose related decrease in time spent drinking, with a rank order potency of dynorphin-(1-13) greater than morphine greater than ethylketocyclazocine greater than [D-Pen2, D-Pen5]enkephalin = U50, 488H. With the exception of morphine, all of the compounds increased the latency to begin drinking, but only at the highest doses tested. The rank order potency for this endpoint was dynorphin-(1-13) = ethylketocyclazocine greater than [D-Pen2, D-Pen5]enkephalin greater than U50, 488H. The potent inhibition of drinking following centrally-given dynorphin-(1-13), at doses that did not affect the latency to begin drinking, supports a role for endogenous dynorphin in the homeostatic control of water balance. This function may not be primarily mediated through activation of a kappa opioid receptor since dynorphin-(1-13) was 80-230 times more potent than the selective kappa agonist, U50,488H or ethylketocyclazocine.
研究了脑室内注射μ（吗啡）、κ（强啡肽 -（1 - 13）、乙基酮环唑辛和U50,488H）以及δ（[D - Pen2，D - Pen5]脑啡肽）阿片类激动剂对14小时禁水大鼠饮水量的影响。所有激动剂均导致饮水时间呈剂量依赖性减少，其效价顺序为强啡肽 -（1 - 13）＞吗啡＞乙基酮环唑辛＞[D - Pen2，D - Pen5]脑啡肽 = U50,488H。除吗啡外，所有化合物均增加了开始饮水的潜伏期，但仅在测试的最高剂量时出现。该终点的效价顺序为强啡肽 -（1 - 13） = 乙基酮环唑辛＞[D - Pen2，D - Pen5]脑啡肽＞U50,488H。在不影响开始饮水潜伏期的剂量下，中枢给予强啡肽 -（1 - 13）后对饮水的有效抑制支持内源性强啡肽在水平衡稳态控制中的作用。该功能可能并非主要通过κ阿片受体的激活介导，因为强啡肽 -（1 - 13）的效力比选择性κ激动剂U50,488H或乙基酮环唑辛强80 - 230倍。
