title: The effect of p-chloromercuribenzoate on structure-binding relationships of muscarinic receptors in the rat cerebral cortex.
abstract: Muscarinic receptors in the rat cerebral cortex, reacted with p-chloromercuribenzoate (PCMB) under different conditions (Phase I and II), have modified binding sites. These exhibit remarkable changes in the structural dependence of the binding of drugs. In Phase I, the structure-binding profile of agonists for both the high and low affinity agonist sites are altered. In Phase II, the structure-binding profile of antagonists is also observed. In Phase II, the ability of potent agonists to discriminate between sub-classes of agonist binding sites is eliminated. There is also a loss of heterogeneity in the binding of the selective antagonist pirenzepine. Of the 16 agonists examined, only pilocarpine has a heterogeneous binding profile in Phase II, the dispersity of binding being increased. The changes in binding properties of the receptors are discussed in terms of general theories of drug-receptor interactions.
mesh_terms: D000818:Animals; D002540:Cerebral Cortex / Q000187:drug effects* / Q000378:metabolism; D002729:Chloromercuribenzoates / Q000494:pharmacology*; D004347:Drug Interactions; D066298:In Vitro Techniques; D018727:Muscarinic Antagonists; D010862:Pilocarpine / Q000378:metabolism; D051381:Rats; D011976:Receptors, Muscarinic / Q000187:drug effects* / Q000378:metabolism; D020245:p-Chloromercuribenzoic Acid
chemical_list: D002729:Chloromercuribenzoates; D018727:Muscarinic Antagonists; D011976:Receptors, Muscarinic; D010862:Pilocarpine; D020245:p-Chloromercuribenzoic Acid