| pubmed-article:11561743 | pubmed:abstractText | To compare the inhibitory effects of a new group of smooth muscle relaxants, the potassium channel openers cromakalim and pinacidil, with those of oxybutynin on detrusor muscle stimulation in animals. Detrusor strips of guinea pigs (n=16) and rabbits (n=20) were mounted in organ bath for recording of isometric tension. Alpha,beta-methylene ATP (10(-7), 10(-6), 10(-5) M), carbachol (10(-6), 10(-5), 3 x 10(-5), 5 x 10(-5) M) and transmural electrical-field stimulation (TES) were applied and concentration-response curves in the absence or presence of cromakalim (10(-6), 10(-5) M), pinacidil (10(-5), 5 x 10(-5) M) and oxybutynin (10(-5), 5 x 10(-5) M) were generated. All curves were displaced to the right in a concentration-dependent manner. The order of potency of inhibition was as follows: alpha,beta-methylene ATP (pinacidil>oxybutynin>cromakalim in guinea pigs; pinacidil>cromakalim>oxybutynin in rabbits); TES (pinacidil>cromakalim>oxybutynin in guinea pigs; cromakalim>oxybutynin>pinacidil in rabbits); carbachol (oxybutynin>pinacidil>cromakalim in guinea pigs; oxybutynin>cromakalim>pinacidil in rabbits). Cromakalim and pinacidil mainly inhibited purinergic-induced (alpha,beta-methylene ATP and TES) detrusor contractions. | lld:pubmed |
