Existing Insulin Therapies

Abstract

The insulin hormone is normally synthesized and stored as insulin--zinc hexameric aggregates in pancreatic beta cells. After release into the blood stream, the insulin complex dissociates into biologically active monomeric and dimeric forms which interact at insulin receptors to affect metabolic action. The aim of exogenously administered insulin therefore is to simulate physiological insulin action based primarily on modification of the human insulin molecule. Insulin has a tendency for self-association into dimers or hexamers. Rapid dissociation of hexamers to monomers accelerates the time to onset of action, whereas retarding agents such as protamine, zinc, amino acid substitutions and site-specific mutagenesis are employed to delay absorption and hence prolong action [1].