Grosvenor C E, Shyr S W, Crowley W R
Endocrinol Exp. 1986 Aug;20(2-3):223-8.
Prolactin (PRL) is present in the milk of lactating rats and, when ingested by the pups, can pass through the gut and enter the systemic circulation. The present study tested whether a suppression of normal milk PRL intake by the pups during early postpartum period affects the subsequent level of activity of the tuberoinfundibular dopamine (TIDA) system. Maternal plasma and milk PRL levels were depressed in lactating rats by daily injections of bromocriptine. Such treatment during postpartum days 2-5, but not during postpartum days 9-12, resulted in a marked suppression of DA turnover in the median eminence (ME), and in an elevation in plasma PRL concentration in the offspring when measured at 33-35 days of age. Simultaneous infusion of ovine PRL (oPRL) by osmotic minipump reversed the effects of neonatal bromocriptine. Catecholamine turnover in the neurointermediate lobe (NIL) was unaffected by any treatment. These results suggest that the normal activity of the TIDA system, but not that of the tuberohypophyseal DA system of the rat, may be impaired by a deficiency of PRL during a critical postpartum period.
催乳素（PRL）存在于哺乳期大鼠的乳汁中，幼崽摄入后可穿过肠道进入体循环。本研究检测了产后早期幼崽正常乳汁PRL摄入量的抑制是否会影响随后的结节漏斗多巴胺（TIDA）系统的活性水平。通过每日注射溴隐亭使哺乳期大鼠的母体血浆和乳汁PRL水平降低。在产后第2 - 5天而非产后第9 - 12天进行这种处理，导致正中隆起（ME）中多巴胺（DA）周转率显著降低，并且在33 - 35日龄时测量，后代血浆PRL浓度升高。通过渗透微型泵同时输注羊催乳素（oPRL）可逆转新生期溴隐亭的作用。神经中间叶（NIL）中的儿茶酚胺周转率不受任何处理的影响。这些结果表明，在关键的产后时期，PRL缺乏可能会损害大鼠TIDA系统的正常活性，但不会损害大鼠结节垂体多巴胺系统的正常活性。
