酮病、脂肪肝奶牛胰岛素受体mRNA丰度

选择自然发生的酮病奶牛、脂肪肝奶牛和正常围产期荷斯坦奶牛（对照）各5头，通过手术方法采取其肝脏样品，采用半定量RT—PCR方法检测了这3组奶牛肝胜样品胰岛素受体（InsR）mRNA丰度的变化。结果表明，酮痛奶牛InsRmRNA相对表达量低于正常对照奶牛，而高于脂肪肝奶牛；脂肪肝奶牛InsR mRNA相对表达量低于正常对照奶牛和酮病奶牛（P〈0．05）。可见，酮病奶牛InsR mRNA相对表达量下降，提示此有利于酮病奶牛糖异生和脂肪动员，从而缓解能量负平衡；脂肪肝奶牛InsR mRNA相对表达量降低，提示奶牛胰岛素应答显著减弱，此时奶牛可能发生了胰岛素抵抗。

Abundance of insulin receptor mRNA in ketosis and fatty liver cows

Five normal multiparous Holstein cows,five ketosis cows and five fatty liver cows were selected at random and used in the present study to determine the relationship between ketosis and fatty liver cows in abundance of InsR mRNA in tissues of liver by the way of RT-PCR. The results shown:Relative expression of InsR mRNA was lower in ketosis cows than in normal cows and higher than in fatty liver cows and ketosis(P<0.05),and was lower in fatty liver cows than in normal cows and ketosis(P<0.05).It is concluded that the lower expression of InsR mRNA in ketosis cows could be helpful to inhibiting fat mobilization and utilizing glucose,thereby relieve the negative energy balance.The lower expression of InsR mRNA in fatty liver cows indicates that these cows exist serious disturbance of insulin respondence and insulin resistance.