Pfeiffer A, Braun S, Mann K, Meyer H D, Brantl V
J Clin Endocrinol Metab. 1986 Jan;62(1):181-5. doi: 10.1210/jcem-62-1-181.
The present study was designed to investigate pituitary hormone responses to a kappa-opiate receptor agonist in man. Normal men were given the racemic benzomorphan kappa-agonist MR 2033 or its levorotatory isomer MR 2034 iv. Plasma levels of PRL and GH markedly increased after injection of 3.5 micrograms/kg MR 2033 or 1.9 or 3.8 micrograms/kg MR 2034. These effects of MR 2033 were blocked by the opiate antagonist naloxone (10 mg), thereby demonstrating their mediation by opiate receptors. The kappa-agonist did not change plasma levels of LH and FSH. The secretion of TSH was significantly suppressed by MR 2033 and MR 2034, but this action was not antagonized by pretreatment with naloxone. The suppression of plasma TSH was, however, stereospecific since the (+)-isomer, MR 2035, did not affect TSH secretion. These data indicate that kappa-opiate receptors are located on neuronal pathways regulating GH, TSH, and PRL secretion. The pattern of pituitary responses elicited by the kappa-agonist differs from that of mu-opioid agonists, indicating differential endocrine functions for the endogenous agonists.
本研究旨在调查人体中垂体激素对κ-阿片受体激动剂的反应。给正常男性静脉注射消旋苯并吗啡烷κ-激动剂MR 2033或其左旋异构体MR 2034。注射3.5微克/千克MR 2033或1.9或3.8微克/千克MR 2034后，血浆中催乳素（PRL）和生长激素（GH）水平显著升高。MR 2033的这些作用被阿片拮抗剂纳洛酮（10毫克）阻断，从而证明其通过阿片受体介导。κ-激动剂未改变促黄体生成素（LH）和促卵泡生成素（FSH）的血浆水平。MR 2033和MR 2034显著抑制促甲状腺激素（TSH）的分泌，但纳洛酮预处理不能拮抗此作用。然而，血浆TSH的抑制具有立体特异性，因为其（+）-异构体MR 2035不影响TSH分泌。这些数据表明κ-阿片受体位于调节GH、TSH和PRL分泌的神经通路上。κ-激动剂引发的垂体反应模式与μ-阿片类激动剂不同，表明内源性激动剂具有不同的内分泌功能。
