Robinson B H
Biol Neonate. 1976;29(1-2):48-55. doi: 10.1159/000240847.
The activities of key gluconeogenic enzymes in the liver of newborn guinea pigs delivered vaginally at term were monitored as a function of time following birth. The activities of glucose-6-phosphatase and fructose-1,6-diphosphatase did not show a significant increase over the first 72 h of life, neither did the activity of mitochondrial phosphoenolpyruvate carboxykinase. The mitochondrial enzyme pyruvate carboxylase and the cytosolic phosphoenolpyruvate carboxykinase (PEPCK) both increased significantly in the first 24 h postpartum. Mitochondrial protein and succinate dehydrogenase activities showed only slight increases in the 72-hour period. Rapid depletion of liver glycogen was evident in these animals following birth, but severe hypoglycaemia was not evident. Mitochondrial and cytosolic PEPCK showed similar kinetic behaviour with respect to their affinities for oxalacetate and divalent metal cation Mn++, though the mitochondrial enzyme would accept Mg++ as the divalent metal in place of Mn++. The role of the compartmented PEPCK activities is discussed.
对足月经阴道分娩的新生豚鼠肝脏中关键糖异生酶的活性，作为出生后时间的函数进行了监测。葡萄糖-6-磷酸酶和果糖-1,6-二磷酸酶的活性在出生后的头72小时内没有显著增加，线粒体磷酸烯醇式丙酮酸羧激酶的活性也没有增加。线粒体酶丙酮酸羧化酶和胞质磷酸烯醇式丙酮酸羧激酶（PEPCK）在产后头24小时内均显著增加。线粒体蛋白和琥珀酸脱氢酶的活性在72小时内仅略有增加。这些动物出生后肝脏糖原迅速消耗，但未出现严重低血糖。线粒体和胞质PEPCK对草酰乙酸和二价金属阳离子Mn++的亲和力表现出相似的动力学行为，尽管线粒体酶可以接受Mg++作为替代Mn++的二价金属。讨论了分隔的PEPCK活性的作用。
