Heap R B, Fleet I R, Hamon M, Brown K D, Stanley C J, Webb A E
Endocrinol Exp. 1986 Aug;20(2-3):101-18.
In this paper we examine the ability of the mammary gland to remove from circulating blood three compounds which differ in their physico-chemical and structural properties. Mammary extraction of progesterone, oestrone sulphate and epidermal growth factor (EGF) is similar at peak lactation in goats, but the proportion of labelled infusate that is transferred into milk is greater for oestrone sulphate and EGF than progesterone which is rapidly metabolised by mammary tissue. The kinetics of transfer of progesterone, oestrone sulphate and EGF from blood into milk show that transcellular processes are involved, and on the basis of earlier hypotheses and new information reported here the results indicate the probable importance of simple and facilitated diffusion pathways for progesterone and oestrone sulphate, and secretory mechanisms for oestrone sulphate and EGF. Although evidence is lacking for a direct effect of hormones in milk on mammary function, their concentration in milk may reflect changes in local regulation of mammary secretion. Considerable practical value is attached to the immunodiagnostic use of milk hormone concentrations to determine ovarian and placental endocrine activity during pregnancy in domestic ruminants.
在本文中，我们研究了乳腺从循环血液中清除三种理化性质和结构不同的化合物的能力。在山羊泌乳高峰期，孕酮、硫酸雌酮和表皮生长因子（EGF）的乳腺提取情况相似，但与迅速被乳腺组织代谢的孕酮相比，硫酸雌酮和EGF转移到乳汁中的标记注入物比例更高。孕酮、硫酸雌酮和EGF从血液转移到乳汁的动力学表明，涉及跨细胞过程，根据此前的假说和本文报道的新信息，结果表明简单扩散和易化扩散途径对孕酮和硫酸雌酮可能很重要，而硫酸雌酮和EGF则通过分泌机制转移。尽管缺乏乳汁中激素对乳腺功能有直接影响的证据，但它们在乳汁中的浓度可能反映乳腺分泌局部调节的变化。利用乳汁激素浓度进行免疫诊断以确定家养反刍动物孕期卵巢和胎盘内分泌活动具有相当大的实用价值。
