Hampshire J, Altszuler N
Am J Vet Res. 1981 Jun;42(6):1073-6.
Base-line values of plasma growth hormone (GH) are low in most species, requiring provocative tests to assess GH deficiency. Clonidine, an antihypertensive drug, and its analogue, xylazine, a sedative hypnotic, were found to stimulate GH secretion. Administration (IV) of clonidine to conscious healthy, dogs at doses of 30, 16.5, and 3 microgram/kg produced significant increases in plasma GH by 15 minutes and the effects subsided by 120 minutes. Plasma glucose concentration increased slowly with all doses, but less so and for shorter duration in dogs given the 3 microgram/kg dose. Xylazine increased plasma GH when injected at doses of 300 and 100 microgram/kg, but not at 30 microgram/kg. Plasma glucose increased only with the 300 microgram/kg dose. The alpha-adrenergic blocker, phentolamine, markedly attenuated these responses. Thus, both clonidine and xylazine, when used at appropriate doses, can stimulate GH secretion, with minimal effect on plasma glucose and without causing significant sedation.
大多数物种的血浆生长激素（GH）基线值较低，需要进行激发试验来评估GH缺乏情况。发现抗高血压药物可乐定及其类似物、镇静催眠药赛拉嗪可刺激GH分泌。对清醒健康犬静脉注射30、16.5和3微克/千克剂量的可乐定，15分钟时血浆GH显著升高，120分钟时作用消退。所有剂量的可乐定都使血浆葡萄糖浓度缓慢升高，但给予3微克/千克剂量的犬升高幅度较小且持续时间较短。赛拉嗪以300和100微克/千克剂量注射时可使血浆GH升高，但30微克/千克剂量时无此作用。仅300微克/千克剂量可使血浆葡萄糖升高。α-肾上腺素能阻滞剂酚妥拉明显著减弱了这些反应。因此，可乐定和赛拉嗪在适当剂量使用时均可刺激GH分泌，对血浆葡萄糖影响最小且不会引起明显镇静作用。
