Data is accumulating indicating that impaired insulin action predisposes to increased vascular smooth muscle (VSM) tone, the hallmark of hypertension associated with diabetes. During the last several years, it has been established that VSM is an insulin-sensitive tissue like skeletal muscle and adipocytes. Investigators have shown that insulin regulates VSM intracellular cation metabolism through attenuating effects on inward calcium (Ca2+) currents and by direct effects on VSM cells (VSMCs) Na+, K+-ATPase pump expression and activity and that insulin and IGF-I stimulate glucose uptake in VSMCs. Furthermore, recent data suggest that IGF-I, like insulin, attenuates cytosolic calcium [Ca2+]i transients and vasoconstrictive responses. IGF-I, like insulin, also stimulates the production of nitric oxide from both the endothelium and VSMCs. IGF-I and insulin are structurally related, share receptors, and have similar postreceptor actions. Unlike insulin, which must transverse the endothelium before acting on VSMCs in vivo, IGF-I is synthesized by VSMCs. Thus, it is likely that IGF-I has more relevance than insulin in regulating physiological parameters in VSMCs.
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ROLE OF INSULIN ACTION IN THE DEVELOPMENT OF ATHEROSCLEROSIS|
July 01 1996
Effects of Insulin and IGF-I on Vascular Smooth Muscle Glucose and Cation Metabolism
James R Sowers
James R Sowers
Departments of Medicine and Physiology, Wayne State University School of Medicine
Detroit, Michigan
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Address correspondence and reprint requests to Dr. James R. Sowers, Professor of Medicine and Physiology, Director, Division of Endocrinology, Metabolism and Hypertension, Wayne State University School of Medicine, UHC-4H, 4201 St. Antoine, Detroit, MI 48201
Citation
James R Sowers; Effects of Insulin and IGF-I on Vascular Smooth Muscle Glucose and Cation Metabolism. Diabetes 1 July 1996; 45 (Supplement_3): S47–S51. https://doi.org/10.2337/diab.45.3.S47
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