PT  - JOURNAL ARTICLE
AU  - KLOOG, YOEL
AU  - HERON, DAVIS S.
AU  - KORCZYN, AMOS D.
AU  - SACHS, DAN I.
AU  - SOKOLOVSKY, MORDECHAI
TI  - Muscarinic Acetylcholine Receptors in Albino Rabbit Iris-Ciliary Body
DP  - 1979 May 01
TA  - Molecular Pharmacology
PG  - 581--587
VI  - 15
IP  - 3
4099  - http://molpharm.aspetjournals.org/content/15/3/581.short
4100  - http://molpharm.aspetjournals.org/content/15/3/581.full
SO  - Mol Pharmacol1979 May 01; 15
AB  - The binding of tritium-labeled N-methyl-4-piperidyl benzilate to homogenates of irisciliary body complex of albino rabbits was investigated. The binding exhibited all the characteristics typical of binding to the muscarinic acetylcholine receptor: it was saturable, of high affinity, and could be reduced by muscarinic non-labeled ligands whereas nonmuscarinic drugs had no such effect. Hill coefficients were approximately 1 for the antagonists and less than 1 for the agonists. Equilibrium experiments indicated the existence of a single population of binding sites (0.44 pmol/irisciliary body). The formation of at least two types of ligand receptor complexes had to be assumed, however, to explain the kinetics of [3H]-N-methyl-4-piperidyl benzilate binding. The simplest model which fits the experimental findings consists of a fast binding step followed by a slow isomerization of the receptor-ligand complex, as previously suggested by us for the muscarinic receptor in the mouse brain. ACKNOWLEDGMENT M. Sokolovsky is an established investigator of the Chief Scientist’s Bureau, Ministry of Health, Israel. The skillful technical assistance of Mrs. Ronit Galron is gratefully acknowledged.