Centre for Biodiscovery and School of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand.
J Proteomics. 2012 Jul 19;75(14):4429-35. doi: 10.1016/j.jprot.2012.04.019. Epub 2012 Apr 24.
The liver and the mammary gland have complementary metabolic roles during lactation. Glucose synthesized by the liver is released into the circulation and is taken up by the mammary gland where major metabolic products of glucose include milk sugar (lactose) and the glycerol backbone of milk fat (triglycerides). Hepatic synthesis of glucose is often accompanied by β-oxidation in that organ to provide energy for glucose synthesis, while mammary gland synthesizes rather than oxidizes fat during lactation. We have therefore compared enzyme abundances between the liver and mammary gland of lactating Friesian cows where metabolic output is well established. Quantitative differences in protein amount were assessed using two-dimensional differential in-gel electrophoresis. As predicted, the abundances of enzymes catalysing gluconeogenesis and β-oxidation were greatest in the liver, and enzyme abundances in mammary tissue were consistent with fat synthesis rather than β-oxidation.
在哺乳期，肝脏和乳腺具有互补的代谢作用。肝脏合成的葡萄糖被释放到循环中，并被乳腺摄取，葡萄糖的主要代谢产物包括乳糖果糖（乳糖）和乳脂肪的甘油骨架（甘油三酯）。肝脏合成葡萄糖通常伴随着该器官中的β-氧化，以为葡萄糖合成提供能量，而在哺乳期，乳腺合成而不是氧化脂肪。因此，我们比较了产奶的弗里生牛的肝脏和乳腺之间的酶丰度，这些牛的代谢产物已经确定。使用二维差异凝胶电泳评估了蛋白质含量的定量差异。正如预测的那样，催化糖异生和β-氧化的酶的丰度在肝脏中最高，而乳腺组织中的酶丰度与脂肪合成而不是β-氧化一致。
