Subtypes of muscarinic receptors in cultured explants of the hippocampus of the rat.
Using the tritiated, muscarinic antagonist quinuclidinyl benzilate ([3H]QNB) as a ligand, muscarinic receptors have been identified and characterized in intact, cultured explants of the hippocampus of the rat. Competition studies with scopolamine and oxotremorine indicated a certain heterogeneity in the population of muscarinic receptors, whereas atropine and pirenzepine competed with [3H]QNB in a manner consistent with only one binding site for these substances. Thus, the observed heterogenity does not fit in with the M1/M2 receptor concept. Extended studies, with the aim of determining to what extent these putative subtypes of receptors are functional, would be of interest.
Waser
P G
PG
Institute of Pharmacology, Zürich, Switzerland.
Rimvall
K
K
D000818:Animals; D001667:Binding, Competitive; D006624:Hippocampus / Q000032:analysis*; D010095:Oxotremorine / Q000378:metabolism; D011813:Quinuclidinyl Benzilate / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D011976:Receptors, Muscarinic / Q000032:analysis*; D012601:Scopolamine / Q000378:metabolism
D011976:Receptors, Muscarinic; D010095:Oxotremorine; D011813:Quinuclidinyl Benzilate; D012601:Scopolamine