Properties and regulation of the T lymphocyte insulin receptor.
Primary human T lymphocytes that have been mitogen activated in chemically defined medium express cell surface insulin receptors. The receptor is identical to other mammalian insulin receptors in binding properties, including: pH dependency, ligand affinity, hormone specificity, and cooperative interactions. Scatchard plots are curvilinear and a ligand-induced increase in dissociation, the property normally associated with "negative cooperativity", is kinetically demonstrable. In vitro insulin treatment of the receptor-negative, resting T lymphocyte slightly enhances the degree of insulin binding which emerges following cellular activation. Insulin treatment of receptor-positive lymphoblasts results in insulin receptor "down-regulation". These findings indicate that T lymphoblast insulin receptor concentrations are not significantly influenced by insulin before their emergence but are dramatically regulated by insulin following their appearance at the cell surface.
D000818:Animals; D005934:Glucagon / Q000502:physiology; D006801:Humans; D066298:In Vitro Techniques; D007328:Insulin / Q000031:analogs & derivatives / Q000502:physiology; D008934:Mitogens / Q000494:pharmacology; D011384:Proinsulin / Q000502:physiology; D011972:Receptor, Insulin / Q000502:physiology*; D013552:Swine; D013601:T-Lymphocytes / Q000502:physiology*
D007328:Insulin; D008934:Mitogens; C024339:insulin, desoctapeptide-; D005934:Glucagon; D011384:Proinsulin; D011972:Receptor, Insulin