整体情况下,吗啡及其他吗啡类物质能抑制促性腺激素的分泌,而鸦片拮抗剂如纳络酮及纳曲酮可明显升高血清LH水平。后一作用被认为是由于鸦片拮抗剂阻断了内源性鸦片样物质在下丘脑水平的紧张性抑制作用。新近有报道,纳络酮可增加垂体门脉血中GnRH的水平。由于垂体前叶能形成大量鸦片肽而且在垂体前叶已发现具有鸦片类受体,这都提示鸦片类化合物可能通过局部作用调节垂体激 Overall, morphine and other morphine substances inhibit gonadotropin secretion, and opiate antagonists such as naloxone and naltrexone can significantly raise serum LH levels. This latter effect is thought to be due to the fact that opioid antagonists block the tonic inhibition of endogenous opioids at the level of the hypothalamus. It has recently been reported that naloxone can increase the level of GnRH in the portal blood of the pituitary gland. Since the anterior pituitary can form large amounts of opiate peptides and has been found to have opiate receptors in the anterior pituitary, this suggests that opiate compounds may modulate pituitary stimulation through local action