Prilusky J, Deis R P
J Endocrinol. 1975 Dec;67(3):397-401. doi: 10.1677/joe.0.0670397.
The effect of L-DOPA on milk ejection and on prolactin release during 30 min of suckling was studied in lactating rats. Various doses of L-DOPA (1-25, 2-5, 5 and 10 mg/100 g body wt) were injected i.p. 30 min before the suckling period. Control rats were injected with 0-9% NaCl solution only. An inhibition of milk ejection proportional to the dose of drug administered was obtained. The dose of 10 mg completely blocked milk ejection but 1-25 mg had no effect. A normal milk-ejection response was obtained with a small dose of oxytocin injected immediately before nursing into mothers treated with 10 mg L-DOPA, indicating that the blocking effect was not due to a lack of mammary gland response. In control mothers, serum prolactin levels increased from 67-2 +/- 25-9 (S.E.M.) to 950-3 +/- 118-7 ng/ml after a 30 min suckling period. L-DOPA (5 and 10 mg) prevented the release of prolactin induced by suckling, but 1-25 and 2-5 mg L-DOPA had no effect. The results indicate that oxytocin and prolactin release induced by suckling in lactating rats is inhibited by an increase of catecholamines at the hypothalamic-hypophysial axis.
在泌乳大鼠中研究了左旋多巴对哺乳30分钟期间乳汁排出及催乳素释放的影响。在哺乳前30分钟腹腔注射不同剂量的左旋多巴（1 - 25、2 - 5、5和10毫克/100克体重）。对照大鼠仅注射0.9%氯化钠溶液。获得了与给药剂量成比例的乳汁排出抑制作用。10毫克剂量完全阻断了乳汁排出，但1 - 25毫克没有效果。在用10毫克左旋多巴处理的母亲哺乳前立即注射小剂量催产素可获得正常的乳汁排出反应，这表明阻断作用不是由于乳腺缺乏反应。在对照母亲中，哺乳30分钟后血清催乳素水平从67.2±25.9（标准误）升高到950.3±118.7纳克/毫升。左旋多巴（5和10毫克）可阻止哺乳诱导的催乳素释放，但1 - 25和2 - 5毫克左旋多巴没有效果。结果表明，下丘脑 - 垂体轴儿茶酚胺增加会抑制泌乳大鼠哺乳诱导的催产素和催乳素释放。
