Cholinergic muscarinic receptors in rat cochlea.
Specific 3H-1-quinuclidinylbenzilate (3H-1-QNB) binding to rat cochlea homogenates occurs to a homogeneous class of binding sites with Kd = 0.13 +/- 0.01 nM and Bmax = 0.57 +/- 0.07 fmol per cochlea. Binding is stereoselectively inhibited by benzetimide enantiomers. Dexetimide was more effective than levetimide in displacing 3H-1-QNB from its binding sites (Ki = 4 x 10(-10) M and 6.5 x 10(-6) M, respectively). Pirenzepine inhibits 3H-1-QNB binding with low affinity (Ki = 2 x 10(-6) M), classifying the binding sites as muscarinic M2 receptors.
van Megen
Y J
YJ
Department of Otorhinolaryngology, University of Nijmegen, The Netherlands.
Klaassen
A B
AB
Rodrigues de Miranda
J F
JF
Kuijpers
W
W
D000818:Animals; D003051:Cochlea / Q000378:metabolism*; D011813:Quinuclidinyl Benzilate / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D011976:Receptors, Muscarinic / Q000378:metabolism*
D011976:Receptors, Muscarinic; D011813:Quinuclidinyl Benzilate