Bdph was synthesized and yielded a light yellow oily substance according to the previously described method [14 ]. Its purity (99.8%) was analyzed by using high performance liquid chromatography and the structure is shown in Figure 1 [15 ]. 4-Aminopiridine (4-AP), atropine sulfate, α-chymotrypsin, diltiazem, glibenclamide (GBC), histamine diphosphate, indomethacin, nicardipine, nifedipine (Nif), pyrilamine maleate, tetraethylammonium bromide (TEA), and verapamil (Vrp) were purchased from Sigma-Aldrich, St. Louis, MO. U.S.A. Papaverine was purchased from Narcotics Bureau, Taipei, Taiwan. Cromakalim, methysergide, and FPL 557121 were gifts from SmithKline Beecham Pharmaceutical, U.K., Sandoz, Swiss, and Fisons, U.K., respectively.
Male Hartley guinea-pigs (250~400 g) were obtained from the Animal Center of the National Science Council (Taipei, Taiwan). The animals were housed in ordinary cages at 22 ± 1°C with a humidity of 50%~60% under a constant 12/12-h light/dark cycle and provided with food and water ad libitum. Under a protocol approved by the Animal Care and Use Committee of Taipei Medical University, the following in vitro experiments were performed.
Male Hartley guinea-pigs (250~400 g) were obtained from the Animal Center of the National Science Council (Taipei, Taiwan). The animals were housed in ordinary cages at 22 ± 1°C with a humidity of 50%~60% under a constant 12/12-h light/dark cycle and provided with food and water ad libitum. Under a protocol approved by the Animal Care and Use Committee of Taipei Medical University, the following in vitro experiments were performed.