Normal insulin binding to cultured fibroblasts from patients with lipoatrophic diabetes

Confluent fibroblasts were assayed for insulin binding to determine whether there was an inherent abnormality in receptor function to explain the insulin resistance of lipoatrophic diabetes (LD). Cells from three patients and four controls were compared for confluent density, receptor saturation, specific and non-specific binding and the concentration of unlabelled hormone producing 50% competition for binding with labelled ligand. Cells from patients with LD did not differ significantly in any of these characteristics from the controls. These findings indicate that there is not a basic defect in insulin receptors of LD patients. A secondary disruption of binding, e.g. by a circulating factor, remains possible.