乳腺灌注必需氨基酸对奶山羊血液生化指标及GHR和IGF-IR mRNA表达量的影响

THE EFFECT OF PERFUSE AMINO ACID ON BLOOD BIOCHEMICAL INDEXS AND CORRELATED HORMONES MRNA EXPRESSION DAIRY GOAT

本试验旨在研究阴外动脉乳蛋白前体物浓度的变化对奶山羊阴外动脉中血液生化指标及对乳腺组织相关激素受体mRNA表达量的影响。选用2周岁3周岁,体重、产奶量相近,并且安装有阴外动脉和乳静脉血插管的关中奶山羊3只,采用3×3拉丁方设计。利用酪蛋白氨基酸模式确定阴外动脉氨基酸灌注量,分别灌注氨基酸缺失量0%（0g/d）、100%（6.8g/d）、120%（8.2g/d）,在灌注前后分别采集动静脉血浆和乳腺组织,测定动静脉血浆中总蛋白、白蛋白、尿素氮、葡萄糖和总胆固醇及乳腺组织GHR和IGF-IR的mRNA表达量。结果表明,两处理组血液中的总蛋白含量极显著高于对照组（P〈0.01）,而白蛋白、葡萄糖和总胆固醇含量显著高于对照组（P〈0.05）,尿素氮含量高于对照组但差异不显著（P〉0.05）。灌注前后采集乳腺组织提取总mRNA,荧光定量PCR发现,灌注氨基酸组GHR和IGF-IR mRNA的表达量极显著高于对照组（P〈0.01）。说明动脉血液中乳蛋白前体物浓度的升高有效地提高了血液中生化指标的含量及乳腺组织中GHR和IGF-IR mRNA的表达量,有利于乳的合成。

The experiment conducted to study the effect of milk protein precursors concentration variation of external pudic artery on blood biochemical indexs and related hormone receptor mRNA expression of mammary gland tissue.Three 23 years old milk goats were chose,which have nearly body weight and milk yield,with the vessel intubation of external pudic artery and milk vein.Perfused amino acid mixture 0g/d、6.8g/d、8.2g/d,through external pudic artery to every goat and every day.AtV blood plasma and mammary gland tissue were collected before and after perfusion,total protein,albumin,urea nitrogen,glucose,total cholesterol in the blood plasma and the mRNA expression of GHR and IGF-IR in the mammary gland tissue were measured.The result showed,which compared with control group,the total protein contents of treatment groups has very significant higher than control group（P〈0.01）,the albumin,glucose and total cholesterol contents have significant higher than control group（P〈0.05）,urea nitrogen contents of treatment groups was higher than control group but has no significant difference（P〉0.05）.Collected mammary gland tissue to extract total mRNA,after the fluorescent quantitation PCR we found,the expression of GHR and IGF-IR mRNA at post-perfusion have very significant higher than ante-perfusion（P〈0.01）,indicated that the elevation of milk protein precursors concentration in arterial blood improved the contents of biochemical indexs and related hormone receptor mRNA expression efficiently,this is profit to milk synthesis.