Anti-alprenolol anti-idiotypic antibodies bind to beta-adrenergic receptors and modulate catecholamine-sensitive adenylate cyclase.
Rabbit antibodies induced against alprenolol, a potent beta-adrenergic antagonist, bind to other antagonists, and, with less avidity, to catecholamine agonists. Anti-idiotypic antibodies were raised against the anti-alprenolol immunoglobulins. The anti-idiotypic antibodies specifically bind and agglutinate turkey erythrocytes; this is not observed for human agglutinate turkey erythrocytes; this is not observed for human or sheep erythrocytes, which are devoid of beta-adrenergic receptors. The anti-idiotypic antibodies compete with (--)-[3H]-dihydroalprenolol for binding on the beta-adrenergic receptors on purified turkey erythrocyte membranes. The binding to the membrane-bound receptors is prevented by preincubation of the anti-idiotypic antibodies with their immunogen, the antialprenolol immunoglobulins. The binding to the receptor is not merely passive: the anti-idiotypic antibodies stimulate basal adenylate cyclase activity [ATP pyrophosphate-lyase (cyclizing), EC 4.6.1.1] and enhance adenylate cyclase activation by catecholamine. These observations support the notion that antiidiotypic antibodies may constitute an "internal image" of the original antigen and may mimic its biological effects.
D000262:Adenylyl Cyclases / Q000378:metabolism*; D000526:Alprenolol / Q000276:immunology*; D000818:Animals; D000888:Antibodies, Anti-Idiotypic; D000937:Antigen-Antibody Reactions; D004910:Erythrocyte Membrane; D007130:Immunoglobulin Idiotypes; D011941:Receptors, Adrenergic / Q000276:immunology*; D011943:Receptors, Adrenergic, beta / Q000276:immunology*; D014422:Turkeys
D000888:Antibodies, Anti-Idiotypic; D007130:Immunoglobulin Idiotypes; D011941:Receptors, Adrenergic; D011943:Receptors, Adrenergic, beta; D000526:Alprenolol; D000262:Adenylyl Cyclases