Effects of papaverine on carbachol- and high K+-induced
contraction in the bovine abomasum |
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| Authors: | Takeharu KANEDA Erika SAITO Hidenori KANDA Norimoto URAKAWA Kazumasa SHIMIZU |
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| Affiliation: | 1)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;2)School of Veterinary Nursing and Technology, Nippon Veterinary and Life Science University, 7–1 Kyonan-cho 1-chome, Musashino, Tokyo 180–8602, Japan |
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| Abstract: | The effects of papaverine on carbachol (CCh) -and high K+- induced contractionin the bovine abomasum were investigated. Papaverine inhibited CCh (1 µM)-and KCl (65 mM) -induced contractions in a concentration-dependent manner. Forskolin orsodium nitroprusside inhibited CCh-induced contractions in a concentration-dependentmanner in association with increases in the cAMP or cGMP contents, whereas papaverineincreased cGMP contents only at 30 µM. Changes in the extracellularCa2+ from 1.5 mM to 7.5 mM reduced verapamil-induced relaxation in highK+-depolarized muscles, but papaverine-induced relaxation did not change.Futhermore, papaverine (30 µM) and NaCN (300 µM)decreased the creatine phosphate contents. These results suggest that the relaxing effectsof papaverine on the bovine abomasum are mainly due to the inhibition of aerobic energymetabolism. |
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| Keywords: | abomasum cAMP cGMP creatine phosphate papaverine |
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