Red Blood Cell Insulin Binding Studies in Reye's Syndrome Survivors and Families

Abstract

RBC insulin binding was examined in Reye's survivors and families of affected patients to determine whether their previously reported hyperinsulinemic responses to oral glucose are accompanied by alterations in insulin binding and could contribute to the hypercatabolism seen in this disorder. The mean (125I)-insulin binding to 3 X 10(9) RBC's was 5.7 +/- SEM 0.4 percent in survivors compared to 6.6 +/- 0.3 in siblings (p less than .05) and 6.6 +/- 0.4 in control children (p = .05). Sex and maturity differences were found with higher binding values in men than women as well as higher values in men than boys. Receptor numbers in survivors were comparable to control values. Average affinities varied widely. Plasma insulin levels were low in the fathers (9 +/- SEM 1.4 uU/ml compared to 18.3 +/- 1.8 for control men and 20 +/- 4.5 for mothers of affected patients). The acute syndrome is accompanied by hypercatabolism in the presence of increased plasma insulin levels and familial clustering of cases and recurrences are known to occur. Reduction in insulin binding may play a role in the acute disease if such is shared by more traditionally hormone-responsive cells.