Kara T C, Patnaik B K
Arch Gerontol Geriatr. 1982 Nov;1(3):219-27. doi: 10.1016/0167-4943(82)90023-1.
The SDH activity of cardiac muscle homogenates reached a peak level in the middle-aged lizards followed by a decline in the old. The inhibition of enzyme activity by oxaloacetate, a competitive inhibitor, declined with advancing age. Both salt and acid solubilities of cardiac muscle collagen declined with advancing age of the lizard. An age-related accumulation of total collagen was evident per organ basis but a reverse trend prevailed on the basis of relative value. Quantitative estimations revealed a loss of DNA in ageing heart; per organ basis the DNA content increased till the lizards were middle-aged showing no further change thereafter. On the other hand the RNA content and the RNA/DNA ratio of cardiac muscle declined between young and middle-aged followed by a rise in the old lizards. The protein content increased with rise in fresh weight of heart during ageing.
心肌匀浆的琥珀酸脱氢酶（SDH）活性在中年蜥蜴中达到峰值水平，随后在老年时下降。草酰乙酸作为竞争性抑制剂对酶活性的抑制作用随年龄增长而下降。蜥蜴心肌胶原蛋白的盐溶性和酸溶性均随年龄增长而下降。按器官计算，总胶原蛋白存在与年龄相关的积累，但按相对值计算则呈现相反趋势。定量估计显示，衰老心脏中的DNA有所损失；按器官计算，DNA含量在蜥蜴中年之前一直增加，此后不再变化。另一方面，心肌的RNA含量和RNA/DNA比值在幼年和中年之间下降，随后在老年蜥蜴中上升。衰老过程中心脏鲜重增加，蛋白质含量也随之增加。
