Massry S G, Fadda G Z, Zhou X J, Chandrasoma P, Cheng L, Filburn C R
Department of Medicine, University of Southern California School of Medicine, Los Angeles.
Kidney Int. 1991 Oct;40(4):662-7. doi: 10.1038/ki.1991.258.
Available data indicate that insulin secretion is impaired with aging. Almost all the studies that examined insulin secretion by old animals did not take into consideration the state of renal function or the blood levels of parathyroid hormone (PTH). Old animals may have chronic renal failure (CRF) and secondary hyperparathyroidism, and both of these conditions impair insulin secretion. It is possible, therefore, that the impaired insulin secretion of aging is not due to old age per se, but rather to associated CRF and excess PTH. The present study examined this issue in adult (6 month old) and senescent rats (2 year old) with and without CRF and excess PTH. Senescent rats without CRF had normal renal function and normal blood levels of PTH, and the values were not different from those observed in adult rats. Creatinine clearance in senescent rats with CRF was significantly (P less than 0.01) lower and serum levels of PTH were significantly (P less than 0.01) higher than in senescent animals without CRF and than in the adult rats as well. Only the senescent rats with CRF displayed glucose intolerance during intravenous glucose tolerance test. For any given level of blood glucose, plasma insulin levels were lower in senescent rats with CRF than in the adult rat or senescent animals without CRF.(ABSTRACT TRUNCATED AT 250 WORDS)
现有数据表明，胰岛素分泌会随着衰老而受损。几乎所有检测老年动物胰岛素分泌的研究都未考虑肾功能状态或甲状旁腺激素（PTH）的血液水平。老年动物可能患有慢性肾衰竭（CRF）和继发性甲状旁腺功能亢进，而这两种情况都会损害胰岛素分泌。因此，衰老导致胰岛素分泌受损可能并非由于衰老本身，而是由于相关的慢性肾衰竭和甲状旁腺激素过量。本研究在有或无慢性肾衰竭和甲状旁腺激素过量的成年（6个月大）和衰老大鼠（2岁）中探讨了这个问题。没有慢性肾衰竭的衰老大鼠肾功能正常，甲状旁腺激素血液水平正常，这些值与成年大鼠中观察到的值没有差异。与没有慢性肾衰竭的衰老动物以及成年大鼠相比，患有慢性肾衰竭的衰老大鼠的肌酐清除率显著降低（P小于0.01），甲状旁腺激素血清水平显著升高（P小于0.01）。只有患有慢性肾衰竭的衰老大鼠在静脉葡萄糖耐量试验中表现出葡萄糖不耐受。对于任何给定的血糖水平，患有慢性肾衰竭的衰老大鼠的血浆胰岛素水平低于成年大鼠或没有慢性肾衰竭的衰老动物。（摘要截短至250字）
