Insulin binding in adipocytes from patients with a phaeochromocytoma (PH) approached that of the controls (C) at low and higher concentrations of unlabeled insulin. The apparent receptor affinity was unchanged (ED50: PH 0.50×10−9M and C0.60×10−9M). Scatchard analysis of the binding data using the negative cooperative model revealed a 46% decrease in the total number of receptors together with no changes in both K−e (PH 0.55×109M−1 and C 0.36×109M−1) and K−f (PH 0.13×109 M−1 and C 0.07×109 M−1). According to the two site model, an altered proportion in the two classes of insulin binding sites was detected. This was accompanied by a catecholamine-desensitization of the adipocytes to the antilipolytic action of insulin. These events could represent a final situation of a chronic and endogeneous regulation by high levels of catecholamines of insulin receptors in human adipose tissue.
Chronic and endogenous regulation of insulin receptors by catecholamines in adipocytes from patients with a phaeochromocytoma
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M. C. Carranza, M. A. Simón, A. Torres, C. Calle; Chronic and endogenous regulation of insulin receptors by catecholamines in adipocytes from patients with a phaeochromocytoma. Biosci Rep 1 April 1990; 10 (2): 201–207. doi: https://doi.org/10.1007/BF01116579
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