本试验旨在研究阴外动脉乳成分前体物浓度的变化对奶山羊乳腺吸收及相关激素受体mRNA表达量的影响。选用2~3岁，体重、产奶量相近、安装有阴外动脉和腹部皮下静脉血插管的关中奶山羊3只，由阴外动脉灌注氨基酸和葡萄糖混合物，在灌注前后分别采集动静脉血浆、乳腺组织，测定动静脉血浆中总蛋白、白蛋白的含量及乳腺组织β-酪蛋白、催乳素受体、生长激素受体和类胰岛素生长因子Ⅰ的mRNA表达量。结果表明，与灌注前相比，乳成分前体物含量及乳腺对其的摄取量均提高（P<0.05）。乳腺组织中β-酪蛋白、生长激素受体和类胰岛素生长因子Ⅰ的mRNA表达量显著提高（P<0.05），催乳素受体的mRNA表达量极显著提高（P<0.01），说明阴外动脉灌注氨基酸、葡萄糖混合物可以显著地提高乳成分前体物的浓度，有效地刺激血液中激素发生变化，提高乳腺组织中相关受体mRNA的表达。

The experiment was conducted to study the effects of the milk component precursors (MCP) concentration in external pudendal artery on nutrients uptake in mammary gland and the expression of related hormone receptor mRNA in mammary tissues of dairy goat. Three dairy goats aged from 2 to 3 years with similar body weight and milk yield, and intubated in the external pudendal artery and the abdominal subcutaneous vein, were selected in this study. A mixture of amino acids and glucose was infused into the external pudendal artery. Arteriovenous plasma and mammary tissues were collected to measure the contents of total protein (TP), albumin (ALB) and the mRNA expression levels of β-casein, prolactin receptor (PRLR), growth hormone receptor (GHR) and insulin-like growth factor Ⅰ (IGF-Ⅰ) in mammary tissues. The result was showed as follows: the concentration of MCP in arteriovenous plasma and the ingestion by to the mammary gland were increased after infusion (P<0.05). The mRNA expression levels of β-casein (P<0.05), GHR (P<0.05), IGF-Ⅰ (P<0.05) and PRLR (P<0.01) in mammary tissues were significantly increased. The infusion increase of amino acids and glucose can increase the concentration of MCP, efficiently stimulate the changes of hormone in the blood, and elevate the expression of the related hormone receptor mRNA in mammary tissues.［Chinese Journal of Animal Nutrition, 2010，22（5）:1314-1319］