BINDING OF PHENYLCYCLOHEXYLGLYCOLOYL ESTER OF HYDROXYETHYLDIMETHYLHYDRAZONIUM (COMPOUND VUFB-3113) TO MUSCARINIC RECEPTORS IN RAT-HEART, SALIVARY-GLAND AND CEREBRAL-CORTEX

Phenylcyclohexylglycoloylester of hydroxyethyldimethylhydrazonium (compound VUFB-3113) has been shown earlier to have a strong antimuscarinic effect on smooth muscle. Its affinity to muscarinic binding sites in homogenates of rat heart ventricles (M2 subtype), submandibular salivary gland (M3 subtype) and brain cortex (predominantly M1 subtype) has now been investigated in radioligand displacement experiments using (H-3)quinuclidinyl benzilate ((H-3)QNB) as a relatively non-specific muscarinic ligand. VUFB-3113 inhibited the binding of (H-3)QNB with pK(i) values of 8.17, 8.73, and 8.52 in the heart, salivary gland, and brain cortex, respectively. It is concluded that the compound has a high affinity for muscarinic binding sites without strong preference for any of the M1-M3 subtypes.