“…The ACh-induced contraction of endothelium-removed preparations was significantly protected against the phenoxybenzamine-effect only by pretreatment with pFHHSiD (2 gM; Figure 7b and (Armstead et al, 1988;Hu & El-Fakahany, 1990) and PD142505 (Schwarz et al, 1994) (Duckles, 1988). However, in arterial preparations derived from either the dog or cat (Rubanyi et al, 1987;Dauphin & Hamel, 1990;Alonso et al, 1991) (Furchgott & Zawadzki, 1980;Angus et al, 1983), several of the autoradiographic or radioligand binding studies failed to detect the presence of muscarinic receptors on endothelial cells of blood vessels (Stephenson et al, 1988;Yamada et al, 1990;De Michele et al, 1991). In contrast, autoradiographic investigations in the rabbit thoracic aorta (Tsukahara et al, 1989) and radioligand binding experiments performed in the bovine thoracic aorta (Brunner & Kukovetz, 1991;Traish et al, 1994) have shown the presence of M1 and/or M3 receptors on endothelial cells.…”