发育中绵羊心脏和肝脏中与丙酮酸和草酰乙酸代谢相关的酶的活性

Edwards E M, Dhand U K, Jeacock M K, Shepherd D A

Biochim Biophys Acta. 1975 Aug 13;399(2):217-27. doi: 10.1016/0304-4165(75)90253-6.

In order to assess whether the potential ability of heart ventricular muscle and liver to metabolise substrates such as alanine, aspartate and lactate varies as the sheep matures and its nutrition changes, the activities of the following enzymes were determined in tissues of lambs obtained at varying intervals between 50 days after conception to 16 weeks after birth and in livers from adult pregnant ewes: lactate dehydrogenase (EC 1.1.1.27), alanine aminotransferase (EC 2.6.1.2), pyruvate kinase (EC 2.7.1.40), pyruvate carboxylase (EC 6.4.1.1), phosphoenolpyruvate carboxykinase (GTP)(EC 4.1.1.32), malate dehydrogenase (EC 1.1.1.37), aspartate aminotransferase (EC 2.6.1.1) and citrate (si)-synthase (EC 4.1.3.7). 2. In the heart a most marked increase in alanine aminotransferase activity was found throughout development. During this period the activities of citrate (si)-synthase, lactate dehydrogenase and pyruvate carboxylase also increased. There were no substantial changes in the activities of aspartate aminotransferase, malate dehydrogenase or pyruvate kinase. Pyruvate kinase activities were five times greater in the heart compared with those found in the liver. No significant activity of phosphoenolpyruvate carboxykinase (GTP) was detected in heart muscle. 3. In the liver the activities of both alanine aminotransferase and aspartate aminotransferase increased immediately following birth although the activity of alanine aminotransferase was lower in livers of pregnant ewes than in any of the lambs. As with alanine aminotransferase the highest activities of lactate dehydrogenase were found during the period of postnatal growth. No marked changes were observed in malate dehydrogenase or citrate (si)-synthase activities during development. A small decline in pyruvate kinase activity occurred whilst the activities of pyruvate carboxylase and phosphoenolpyruvate carboxykinase (GTP) tended to rise during development.

为了评估随着绵羊成熟及其营养状况的变化，心室肌和肝脏代谢丙氨酸、天冬氨酸和乳酸等底物的潜在能力是否会发生变化，我们测定了受孕后50天至出生后16周不同时间点获取的羔羊组织以及成年怀孕母羊肝脏中以下酶的活性：乳酸脱氢酶（EC 1.1.1.27）、丙氨酸氨基转移酶（EC 2.6.1.2）、丙酮酸激酶（EC 2.7.1.40）、丙酮酸羧化酶（EC 6.4.1.1）、磷酸烯醇式丙酮酸羧激酶（GTP）（EC 4.1.1.32）、苹果酸脱氢酶（EC 1.1.1.37）、天冬氨酸氨基转移酶（EC 2.6.1.1）和柠檬酸（si）合酶（EC 4.1.3.7）。2. 在心脏中，整个发育过程中丙氨酸氨基转移酶活性有最显著的增加。在此期间，柠檬酸（si）合酶、乳酸脱氢酶和丙酮酸羧化酶的活性也有所增加。天冬氨酸氨基转移酶、苹果酸脱氢酶或丙酮酸激酶的活性没有实质性变化。心脏中的丙酮酸激酶活性是肝脏中的五倍。在心肌中未检测到磷酸烯醇式丙酮酸羧激酶（GTP）的显著活性。3. 在肝脏中，出生后丙氨酸氨基转移酶和天冬氨酸氨基转移酶的活性立即增加，尽管怀孕母羊肝脏中的丙氨酸氨基转移酶活性低于任何一只羔羊。与丙氨酸氨基转移酶一样，乳酸脱氢酶的最高活性出现在出生后生长阶段。发育过程中苹果酸脱氢酶或柠檬酸（si）合酶的活性没有明显变化。丙酮酸激酶活性略有下降，而丙酮酸羧化酶和磷酸烯醇式丙酮酸羧激酶（GTP）的活性在发育过程中趋于上升。