Correlation between insulin receptor binding in isolated fat cells and insulin sensitivity in obese human subjects

Abstract

This study examined the relationship between receptor binding of insulin in a metabolically significant target tissue in vitro and sensitivity to insulin in vivo in obese human subjects. Specific insulin binding was measured at 24°C in isolated enlarged fat cells obtained from 16 patients, by observing the effect of increasing concentrations of unlabeled insulin on the binding of [125I]insulin. Scatchard plots of the binding data were curvilinear with an upward concavity, similarly shaped, and essentially parallel. Kinetic studies on the dissociation of [125I]insulin from fat cells indicated that these curvilinear Scatchard plots could be explained by the presence of site:site interactions o..