[Detection of muscarinic receptors on cultivated endothelial cells]

In order to contribute to the verification of the hypothesis of Furchgott et al. that the effect of acetylcholine on blood vessels is mediated by factors produced by endothelial cells, the authors tried to provide evidence for the existence of muscarinic receptors on these cells. Using cultivated cells of the endothelium of calve aortas, a specific saturable binding of the potent muscarinic antagonist 3H-Quinuclidinyl benzilate and therewith the existence of muscarinic receptors on the cells could be demonstrated. Long time cultivation leads to the disappearance of the receptors.