Insulin binding to circulating monocytes and erythrocytes in patients with non-insulin-dependent diabetes in the young

¹²⁵I-insulin binding to circulating monocytes and erythrocytes was carried out in 9 patients with non-insulin-dependent diabetes in the young (NIDDY), who belonged to families in which non-insulin-dependent diabetes was transmitted through 3 generations. The diabetics had a decreased mean maximum specific binding to monocytes 2.1 (1.1-4.1%) compared to 4.0 (2.6-6.2%) in their age, sex and weight matched reference subjects. This decreased binding was primarily due to a decrease in receptor number as all diabetics had normal affinity values (2-10 ng/ml). We have attributed the decreased binding in NIDDY to the down regulatory effect of the basal hyperinsulinemia (23.6 ± 3.2 vs 11.7 ± 0.5 μU/ml). By contrast the maximum specific binding to erythrocyte was similar in both groups (9.7 ± 0.5; 8.9 ± 0.5%; p > 0.5).