title: Beta-adrenergic receptors on human suppressor, helper, and cytolytic lymphocytes.
abstract: Using the radioligand beta-adrenergic blocker [125I]cyanopindolol (ICYP), we have characterized the beta-adrenergic receptors on Leu 3+ (T helper [TH]), Leu 2+, 9.3- (T suppressor [Ts]) and Leu 2+, 9.3+ (T cytolytic [Tc]) subsets of human lymphocytes. Peripheral blood T cells were isolated by rosetting, and then subsets were purified by their affinities to monoclonal antibodies against their Leu 3 and 9.3 markers. ICYP binding to the subsets was saturable with time and with concentration; the binding was stereoselective and reversible by beta-adrenergic antagonists. A biological response produced by beta agonists increased intracellular concentrations of cAMP and corresponded to the number of binding sites. Each subset of cells had a number of binding sites, which was characteristic for the given subset. The data indicate that the density of distribution of beta-adrenergic receptors was not homogeneous on the precursors of phenotypically and functionally distinct T cells (Ts approximately 2900, Tc approximately 1800 and TH approximately 750 binding sites). The displacement studies using beta-adrenergic agonists were performed on the cytolytic and suppressor T cell subsets, suggesting that the receptors were mainly of the beta-2 type. The immunobiological significance of such selective distribution of numbers and subtypes of beta-adrenergic receptors on distinct T cell subsets is under investigation.
mesh_terms: D004837:Epinephrine / Q000378:metabolism; D006801:Humans; D020120:Iodocyanopindolol; D007545:Isoproterenol / Q000378:metabolism; D009638:Norepinephrine / Q000378:metabolism; D010869:Pindolol / Q000031:analogs & derivatives / Q000378:metabolism; D011433:Propranolol / Q000378:metabolism; D011943:Receptors, Adrenergic, beta / Q000378:metabolism*; D013237:Stereoisomerism; D013602:T-Lymphocytes, Cytotoxic / Q000378:metabolism*; D006377:T-Lymphocytes, Helper-Inducer / Q000378:metabolism*; D050378:T-Lymphocytes, Regulatory / Q000378:metabolism*; D013997:Time Factors
chemical_list: D011943:Receptors, Adrenergic, beta; D020120:Iodocyanopindolol; D011433:Propranolol; D010869:Pindolol; D007545:Isoproterenol; D009638:Norepinephrine; D004837:Epinephrine