Tancer M E, Stein M B, Uhde T W
Biological Psychiatry Branch, National Institute of Mental Health, Bethesda, Maryland 20892.
Psychoneuroendocrinology. 1990;15(4):253-9. doi: 10.1016/0306-4530(90)90075-k.
To investigate the relationship between the plasma growth hormone (GH) response to provocative challenge with the hypothalamic peptide growth hormone-releasing factor (GRF) and the alpha 2-adrenergic agonist clonidine, we administered GRF (1 microgram/kg), clonidine (2 micrograms/kg), and placebo to 21 healthy normal controls (13 men and eight women). Both clonidine and GRF caused significant increases in plasma GH levels over baseline. The peak GH-responses to GRF and clonidine were similar (GRF = 8.7 +/- 6.7 ng/ml; clonidine = 6.5 +/- 5.9 ng/ml; Wilcoxon test: s = 361, z = -1.31, p = NS). The GH responses to GRF and clonidine were significantly correlated (rs = 0.62, n = 20, p = 0.004). Unexpectedly, we found that five of the 21 (26%) normal controls had no GH secretory response to either GRF or clonidine. There was a modest gender effect with clonidine (men greater than women; p less than 0.06) and a negative correlation between GH secretion and age with both GRF and clonidine. Neither GRF nor clonidine had an effect on cortisol levels (DRUG x TIME interaction: F(8,152) = 0.60, p = NS). These findings are consistent with animal studies suggesting that the GH response to clonidine is mediated by GRF. The age and gender effects underscore the importance of careful matching for these factors in studies measuring the GH secretory response.
为了研究血浆生长激素（GH）对下丘脑肽生长激素释放因子（GRF）激发试验的反应与α2 - 肾上腺素能激动剂可乐定之间的关系，我们对21名健康正常对照者（13名男性和8名女性）给予GRF（1微克/千克）、可乐定（2微克/千克）和安慰剂。可乐定和GRF均使血浆GH水平较基线显著升高。GRF和可乐定的GH峰值反应相似（GRF = 8.7±6.7纳克/毫升；可乐定 = 6.5±5.9纳克/毫升；Wilcoxon检验：s = 361，z = -1.31，p = 无显著性差异）。GRF和可乐定的GH反应显著相关（rs = 0.62，n = 20，p = 0.004）。出乎意料的是，我们发现21名正常对照者中有5名（26%）对GRF或可乐定均无GH分泌反应。可乐定存在适度的性别效应（男性大于女性；p < 0.06），且GRF和可乐定的GH分泌与年龄均呈负相关。GRF和可乐定对皮质醇水平均无影响（药物×时间交互作用：F(8,152) = 0.60，p = 无显著性差异）。这些发现与动物研究一致，提示可乐定的GH反应由GRF介导。年龄和性别效应强调了在测量GH分泌反应的研究中仔细匹配这些因素的重要性。
