Burich R L
J Gerontol. 1975 Sep;30(5):539-45. doi: 10.1093/geronj/30.5.539.
The activities of renal lactate and malate dehydrogenases, glutaminase, and Na-K-ATPase were determined in aging male C57BL/6 mice. Urine concentrating ability in these mice and renal response to metabolic acidosis were also studied. Total enzyme activities were measured in vitro in tissue homogenates from mice that were 120, 400, 500, 600, 700, and 800 days old. Urine concentrating ability was determined in these mice prior to sacrifice. Lactate and malate dehydrogenase activities decreased between 120 and 700 days with only male dehydrogenase activity increasing between 700 and 800 days. Age did not affect glutaminase or Na-K-ATPase activities and urine concentrating ability was decreased only at 700 days. Both urine ammonia excretion and renal glutaminase activity increased at 120 and 600 days in response to metabolic acidosis. However, only 5 of 12 animals tested at 600 days survived the acid stress for a full 7 days.
测定了衰老雄性C57BL/6小鼠肾脏中乳酸脱氢酶、苹果酸脱氢酶、谷氨酰胺酶和钠钾ATP酶的活性。还研究了这些小鼠的尿液浓缩能力以及肾脏对代谢性酸中毒的反应。在体外测量了120、400、500、600、700和800日龄小鼠组织匀浆中的总酶活性。在处死这些小鼠之前测定其尿液浓缩能力。乳酸脱氢酶和苹果酸脱氢酶活性在120至700天之间下降，只有雄性脱氢酶活性在700至800天之间增加。年龄不影响谷氨酰胺酶或钠钾ATP酶活性，尿液浓缩能力仅在700天时下降。在120和600天时，尿液氨排泄和肾脏谷氨酰胺酶活性均因代谢性酸中毒而增加。然而，在600天测试的12只动物中，只有5只在酸应激下存活了整整7天。
