The binding of [3H]telenzepine to muscarinic acetylcholine receptors in calf forebrain.

Telenzepine binds to calf brain muscarinic receptors with a selectivity for M1 receptors that is comparable to that exhibited by pirenzepine. Telenzepine has a 10-fold higher affinity than pirenzepine at these receptors and is equipotent with atropine. Because of its potency, selectivity and hydrophilicity, [3H]telenzepine is an excellent radioligand for binding to and monitoring M1 receptor binding sites. The kinetics of [3H]telenzepine binding are extremely slow, even at 37 degrees C.