title: Subpopulations of human T lymphocytes. XII. In vitro effect of agents modifying intracellular levels of cyclic nucleotides on T cells with receptors for IgM (T mu), IgG (T gamma), or IgA (T alpha).
abstract: Purified peripheral blood T lymphocytes were incubated with inducers of cyclic nucleotides and examined for the numbers of T cells with receptors for IgM (T mu), IgG (T gamma), or IgA (T alpha). Isoproterenol and theophylline, agents known to increase cAMP levels at 10(-3) to 10(-6) M concentrations, significantly decreased the number of T mu cells but had no effect on T gamma or T alpha cell numbers. This effect of isoproterenol could be completely blocked by a beta-adrenergic blocking agent, propranolol. Receptors for IgM on T mu cells regenerated after treatment with theophylline when cells were washed and further incubated at 37 degrees C over a period of 12 to 24 hr in the absence of theophylline. Phenylephrine, at 10(-3) to 10(-6) M concentrations, significantly increased the numbers of T mu cells but had no effect on T gamma or T alpha cell numbers. The effect of phenylephrine could be completely blocked with an alpha-adrenergic blocking agent, phentolamine. The significance of the results are discussed.
mesh_terms: D006801:Humans; D007070:Immunoglobulin A / Q000276:immunology*; D007074:Immunoglobulin G / Q000276:immunology*; D007075:Immunoglobulin M / Q000276:immunology*; D007545:Isoproterenol / Q000494:pharmacology; D009712:Nucleotides, Cyclic; D010646:Phentolamine / Q000494:pharmacology; D010656:Phenylephrine / Q000494:pharmacology; D011433:Propranolol / Q000494:pharmacology; D011961:Receptors, Fc / Q000096:biosynthesis*; D013601:T-Lymphocytes / Q000145:classification* / Q000276:immunology; D013806:Theophylline / Q000494:pharmacology
chemical_list: D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D009712:Nucleotides, Cyclic; D011961:Receptors, Fc; D010656:Phenylephrine; D011433:Propranolol; D013806:Theophylline; D007545:Isoproterenol; D010646:Phentolamine