The role of insulin-receptor interactions in regulation of nutrient utilization by skeletal muscle and adipose tissue: a review.

Abstract

Animal growth is a direct function of tissue growth. Tissue growth in turn is dependent upon the rate and extent of hypertrophy and hyperplasia of cells comprising the respective tissues. Cellular enlargement occurs as the result of nutrient uptake by the cell and the balance between anabolic and catabolic processes that regulate accretion of component and structural material of the cell. It is quite clear that the availability, uptake and intracellular metabolism of nutrients are markedly affected by the endocrine system. This review discusses the role of insulin-receptor interactions in the regulation of nutrient uptake and utilization by myofibers and adipocytes. Binding of insulin to specific receptors on the plasma membrane of target cells is important because of its role in mediation of hormone action. Although insulin binding is essential for hormone action, binding may not represent the rate-limiting step on the action of insulin. Recent evidence suggests that insulin is internalized by target cells. However, the physiological role of insulin internalization has not been elucidated. A better understanding of the basic mechanisms by which insulin and other hormones regulate nutrient utilization by skeletal muscle and adipose tissue during growth may lead to improvements in growth rates and the efficiency with which dietary components are used for tissue growth.