title: Effects of papaverine on carbachol- and high K+ -induced contraction in the bovine abomasum.
abstract: The effects of papaverine on carbachol (CCh) -and high K(+)- induced contraction in the bovine abomasum were investigated. Papaverine inhibited CCh (1 µM) -and KCl (65 mM) -induced contractions in a concentration-dependent manner. Forskolin or sodium nitroprusside inhibited CCh-induced contractions in a concentration-dependent manner in association with increases in the cAMP or cGMP contents, whereas papaverine increased cGMP contents only at 30 µM. Changes in the extracellular Ca(2+) from 1.5 mM to 7.5 mM reduced verapamil-induced relaxation in high K(+)-depolarized muscles, but papaverine-induced relaxation did not change. Furthermore, papaverine (30 µM) and NaCN (300 µM) decreased the creatine phosphate contents. These results suggest that the relaxing effects of papaverine on the bovine abomasum are mainly due to the inhibition of aerobic energy metabolism.
authors.affiliation: Laboratory of Veterinary Pharmacology, School of Veterinary Medicine, Nippon Veterinary and Life Science University, 7-1 Kyonan-cho 1-chome, Musashino, Tokyo 180-8602, Japan.
authors.forename: Takeharu
authors.initials: T
authors.lastname: Kaneda
authors.forename: Erika
authors.initials: E
authors.lastname: Saito
authors.forename: Hidenori
authors.initials: H
authors.lastname: Kanda
authors.forename: Norimoto
authors.initials: N
authors.lastname: Urakawa
authors.forename: Kazumasa
authors.initials: K
authors.lastname: Shimizu
mesh_terms: D000018:Abomasum / Q000187:drug effects*; D000276:Adjuvants, Immunologic / Q000494:pharmacology; D000818:Animals; D002217:Carbachol / Q000494:pharmacology*; D002417:Cattle; D018679:Cholinergic Agonists / Q000494:pharmacology; D005576:Colforsin / Q000494:pharmacology; D009119:Muscle Contraction / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects; D020030:Nitric Oxide Donors / Q000494:pharmacology; D009599:Nitroprusside / Q000494:pharmacology; D010208:Papaverine / Q000494:pharmacology*; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology; D011188:Potassium / Q000494:pharmacology*
chemical_list: D000276:Adjuvants, Immunologic; D018679:Cholinergic Agonists; D020030:Nitric Oxide Donors; D010726:Phosphodiesterase Inhibitors; D009599:Nitroprusside; D005576:Colforsin; D002217:Carbachol; D010208:Papaverine; D011188:Potassium