促甲状腺素释放激素与μ、δ和κ阿片受体的作用关系初步观察

Relationship between thyrotropin releasing hormone and effects of μ , δ and κ opioid receptors

本实验用豚鼠回肠，小鼠输精管和兔输精管为实验对象，用特异性阿片受体激动剂和拮抗剂为工具药，从定性，定量两方面研究了促甲状腺素释放激素（ＴＲＨ）与μ，δ，κ亚型阿片受体的关系。结果显示ＴＲＨ（０．０１ｍｍｏｌ／Ｌ）可拮抗Ｄ－丙２，Ｄ－亮５－脑啡肽（ＤＡＤＬＥ）抑制小鼠输精管的收缩反应，同时可使ＤＡＤＬＥ的对数浓度反应曲线（ＬＣＣＲＣ）右移，其拮抗参数ｐＡ２值为９．３，但ＴＲＨ不拮抗双氢埃托啡（ＤＨＥ）抑制豚鼠回肠及埃托啡（Ｅｔｏ）抑制兔输精管的收缩反应，对ＤＨＥ及Ｅｔｏ的ＬＣＣＲＣ无明显影响，结果提示ＴＲＨ拮抗阿片肽的作用有一定的受体亚型选择性。

The relationship between thyrotropin releasing hormone (TRH) and effects of μ , δ and κ opioid receptors was qualitatively and quantitatively studied using guinea pig ileum and mouse and rabbit vas deferens as the subjects and specific agonists and antagonists to opioid receptors as tool drugs. It was found that TRH (0.01 mmol/L) antagonized the inhibition of contraction of isolated mouse vas deferens by D Ala2 and D Leu5 enkephalin (DADLE) with a antagonizing parameter (pA2) of 9.3 to result in the right shift of the logarithm cumulative concentration response curve (LCCRC) of DADLE. But it did not antagonize the inhibition of the contraction of guinea pig ileum and rabbit vas deferens respectively by dihydroetorphine (DHE) and etorphine (Eto) to result in no significant changes of their LCCRC. These findings suggest that TRH selectively antagonize the subtypes of opioid receptors, which might be associated with only the δ opioid receptor.