Impaired insulin-induced RNA synthesis secondary to a genetically defective insulin receptor

The stimulation of glucose uptake and RNA synthesis by insulin was studied in cultured fibroblasts from patients with an inherited affinity defect of the insulin receptor. Additional cell cultures were set up of two patients with Alstrøm syndrome, a genetic disease with insulin resistance but normal insulin receptor, and of eight healthy individuals. In receptor-defective patients we found a corresponding defect of the insulin-mediated stimulation of RNA synthesis but a normal stimulation of glucose uptake. We conclude that both postreceptor effects are controlled by different insulin-directed mechanisms.