Panerai A E, Casanueva F, Martini A, Mantegazza P, Di Giulio A M
Endocrinology. 1981 Jun;108(6):2400-2. doi: 10.1210/endo-108-6-2400.
This study was conducted in order to further understand whether the effect of opiates on growth hormone and prolactin release was exerted centrally or at least in part peripherally. Male rats were treated with morphine-HCl after pretreatment with saline with either the opiate antagonist naloxone-HCl or the quaternary derivative naloxone methyl bromide (Naloxone-Br), the latter of which does not cross the blood brain barrier. Morphine-HCl elicited a clear cut increase in prolactin and growth hormone release after pretreatment with naloxone-Br, but not after pretreatment with naloxone-HCl. Naloxone-Br, however, was able to inhibit the effect of morphine when administered directly in the brain ventricles. To further confirm these results, we administered the quaternary derivative morphine-methyl-iodide (morphine-I), which unlike morphine-HCl, does not cross the blood brain barrier. Morphine-I was ineffective in eliciting growth hormone and prolactin release when administered peripherally, but was effective when administered intraventricularly.
进行本研究是为了进一步了解阿片类药物对生长激素和催乳素释放的影响是通过中枢作用，还是至少部分通过外周作用来实现的。雄性大鼠先用生理盐水预处理，随后分别用阿片拮抗剂盐酸纳洛酮或季铵衍生物甲基溴化纳洛酮（纳洛酮 - Br）进行处理，后者不能穿过血脑屏障。在用纳洛酮 - Br预处理后，盐酸吗啡能引起催乳素和生长激素释放明显增加，但在用盐酸纳洛酮预处理后则不然。然而，当直接注入脑室时，纳洛酮 - Br能够抑制吗啡的作用。为了进一步证实这些结果，我们给予了季铵衍生物甲基碘化吗啡（吗啡 - I），它与盐酸吗啡不同，不能穿过血脑屏障。外周给药时，吗啡 - I在引发生长激素和催乳素释放方面无效，但脑室给药时则有效。
