The Action of Insulin on Target Tissues

 

The prompt action of insulin in the human body is the reduction of the blood glucose level and it is enhanced by the transport of glucose from the blood across the plasma membrane of the muscle and fat cells into the intracellular space. Insulin has also prompt action in converting the glycogen synthetase to an active form and it inhibits lipolysis. Because of this reason, in the peripheral tissues there is enhanced conversion of blood glucose into glycogen and lipids and an increased oxidation of glucose to carbon dioxide.

            Insulin is responsible for the promotion of protein synthesis from amino acids and enhances the induction of glucokinase and phosphofructokinase and suppresses the formation of certain enzymes in gluconeogenesis such as pyruvate carboxylase and fructose diphosphatase.  Insulin appears to have generalized action on the plasma membrane of its target cells, causing it to undergo changes that leads to enhanced entry not only of glucose but also of amino acids, lipids and potassium followed by increased biosynthesis of protoplasm and storage products.

Source :- Biochemistry Second Edition, The Molecular Basis of Cell Structure and Function, Albert L. Lehninger, The Johns Hopkins University School of Medicine, Page number 820-821.

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