RT Journal Article SR Electronic T1 Immunological detection of muscarinic receptor subtype proteins (m1-m5) in rabbit peripheral tissues. JF Molecular Pharmacology JO Mol Pharmacol FD American Society for Pharmacology and Experimental Therapeutics SP 459 OP 462 VO 40 IS 4 A1 Dörje, F A1 Levey, A I A1 Brann, M R YR 1991 UL http://molpharm.aspetjournals.org/content/40/4/459.abstract AB Employing subtype-specific antisera, we have measured the relative levels of five muscarinic receptor subtype proteins (m1-m5) in rabbit peripheral tissues. Immunoprecipitation assays demonstrated the presence of four distinct receptor proteins (m1-m4), which showed notable differences in their tissue distribution. Significant amounts of m5 receptors were not detected in any of the tissues examined. High levels of m1 receptors were found in sympathetic ganglia and submaxillary gland. The m1 receptor was the predominant subtype in vas deferens. Muscarinic receptors of the m2 type were present in varying proportions in all tissues examined, being the major subtype in sympathetic ganglia, ileum, and uterus and the only subtype detected in rabbit atrium. The m3 receptor protein was abundant in submaxillary gland but was not detected at appreciable levels in other tissues studied. Receptors of the m4 type represented a major subtype in peripheral lung and were also present, although at lower levels, in uterine and ileal tissues.