Shiraishi T, Morimoto S, Itoh K, Miyashita Y, Kitano S, Nabata T, Inoue T, Morita R, Taniguchi K, Fukuo K
Department of Geriatric Medicine, Osaka University Medical School.
Nihon Ronen Igakkai Zasshi. 1991 May;28(3):371-6. doi: 10.3143/geriatrics.28.371.
We studied the influence of aging on the stimulatory effect of parathyroid hormone (PTH) to (Ca2+ + Mg2+)-ATPase activity of rabbit renal basolateral membrane (BLM). Stimulated by PTH, (Ca2+ + Mg2+)-ATPase activity of BLM from aged rabbits was lower than those from young rabbits. However, the stimulatory effect of cyclic AMP (cAMP) showed no differences in terms of (Ca2+ + Mg2+)-ATPase activity in BLM from aged and young rabbits. As cAMP production in BLM caused by PTH stimulation was not measured, it is unclear whether cAMP production is different in BLM from young and aged rabbits. From these results, we concluded that in BLM from aged rabbit, the lower effect of PTH on (Ca2+ + Mg2+)-ATPase is due to lower production of cAMP or some other disorder of the PTH signal transduction mechanism. As (Ca2+ + Mg2+)-pump plays an important role in Ca2+ reabsorption in kidney, its lower activity in aged rabbit may be one reason for aberration of renal calcium handling.
我们研究了衰老对甲状旁腺激素（PTH）刺激兔肾基底外侧膜（BLM）的（Ca2+ + Mg2+）-ATP酶活性的影响。在PTH刺激下，老年兔BLM的（Ca2+ + Mg2+）-ATP酶活性低于年轻兔。然而，环磷酸腺苷（cAMP）的刺激作用在老年兔和年轻兔BLM的（Ca2+ + Mg2+）-ATP酶活性方面没有差异。由于未测定PTH刺激引起的BLM中cAMP的产生，尚不清楚年轻兔和老年兔BLM中cAMP的产生是否不同。从这些结果中，我们得出结论，在老年兔的BLM中，PTH对（Ca2+ + Mg2+）-ATP酶的作用较低是由于cAMP产生较低或PTH信号转导机制的其他一些紊乱。由于（Ca2+ + Mg2+）泵在肾脏Ca2+重吸收中起重要作用，其在老年兔中的活性较低可能是肾钙处理异常的一个原因。
