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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| Institution: | 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 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
Ca2+ from 1.5 mM to 7.5 mM reduced verapamil-induced relaxation in high
K+-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 effects
of papaverine on the bovine abomasum are mainly due to the inhibition of aerobic energy
metabolism. |
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| Keywords: | abomasum cAMP cGMP creatine phosphate papaverine |
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