Lorenzi M, Tsalikian E, Bohannon N V, Gerich J E, Karam J H, Forsham P H
J Clin Endocrinol Metab. 1977 Dec;45(6):1154-8. doi: 10.1210/jcem-45-6-1154.
In 6 normal subjects, L-dopa (500 mg PO) and apomorphine (0.6 mg sc) increased circulating growth hormone and suppressed prolactin levels in a parallel and quantitatively similar fashion, but only L-dopa induced a rise in plasma glucagon, glucose, and insulin levels. The failure of apomorphine to affect glucagon secretion, despite a substantial effect on growth hormone and prolactin, was also observed in insulin-dependent diabetics known to exhibit A-cell hyperresponsiveness to various stimuli. In view of the highly dissimilar molecular and pharmacologic characteristics of L-dopa and apomorphine, these data do not exclude a local dopaminergic effect of L-dopa at the pancreatic level, but strongly militate against a central dopaminergic pathway for glucagon stimulation.
在6名正常受试者中，左旋多巴（口服500毫克）和阿扑吗啡（皮下注射0.6毫克）以平行且在数量上相似的方式增加了循环生长激素水平并抑制了催乳素水平，但只有左旋多巴引起血浆胰高血糖素、葡萄糖和胰岛素水平升高。在已知对各种刺激表现出A细胞高反应性的胰岛素依赖型糖尿病患者中，也观察到阿扑吗啡尽管对生长激素和催乳素有显著影响，但未能影响胰高血糖素分泌。鉴于左旋多巴和阿扑吗啡在分子和药理学特性上高度不同，这些数据并不排除左旋多巴在胰腺水平存在局部多巴胺能效应，但有力地反对通过中枢多巴胺能途径刺激胰高血糖素分泌。
