小児インスリン依存性糖尿病における赤血球膜Na⁺, K⁺-ATPase活性の検討

抄録

Na⁺, K⁺-ATPase activity and insulin binding to erythrocytes were studied in insulin dependent diabetic children. The Na⁺, K⁺-ATPase activity (μg phosphate/hr/mg protein : mean±SD) of the well controlled group (N=11), the poorly controlled group (N=12) and age-matched controls (N=10) were 3.99±1.49, 2.18±1.07 and 3.79±0.98, respectively. Maximum% insulin binding (% : mean±SD) of the three groups were 5.9±1.1, 4.4±1.2 and 6.8±1.0, respectively. The Na⁺, K⁺-ATPase activity and maximum % insulin binding of the poorly controlled group were significantly lower than those of the well-controlled group and controls (p <0.01). Between the well controlled group and controls, there was no significant difference. The blood glucose and glycohemoglobin of the poorly controlled group were higher than those of the well-controlled group (p < 0.02 and p < 0.01, respectively), although the blood levels of free insulin were not different between them.
From these data, we speculated that insulin insensitivity was presented in the poorly controlled group and that the decrease of Na⁺, K⁺-ATPase activity in the poorly controlled IDDM was a consequence of the decrease of insulin binding to erythrocytes.