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The effects of papaverine and forskolin on the cAMP (A) or papaverine and SNP on the cGMP (B) contents of the bovine abomasum. Preparations were precontracted with 1 µM CCh and then treated with the specified agents for 10 min. The control was treated with vehicle instead of these agents. Each point represents the mean of 4 experiments. Vertical bars indicate the SEM. * and **: Significant difference from each respective control, with P<0.05 and P<0.01, respectively.
Source publication
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...
Contexts in source publication
Context 1
... of Papaverine, forskolin and SNP on cAMP and cGMP contents: In the presence of CCh (1 µM), forskolin (3 and 10 µM) increased the cAMP contents in a concentration- dependent manner, but papaverine (10 and 30 µM) did not change cAMP contents (Fig. 2A). By contrast, SNP (1 and 10 µM) increased cGMP contents in a concentration-dependent manner, but only the higher concentration of papaverine (30 µM) increased the cGMP contents, and this dose induced maximum relaxation (Fig. ...
Context 2
... of Papaverine, forskolin and SNP on cAMP and cGMP contents: In the presence of CCh (1 µM), forskolin (3 and 10 µM) increased the cAMP contents in a concentration- dependent manner, but papaverine (10 and 30 µM) did not change cAMP contents (Fig. 2A). By contrast, SNP (1 and 10 µM) increased cGMP contents in a concentration-dependent manner, but only the higher concentration of papaverine (30 µM) increased the cGMP contents, and this dose induced maximum relaxation (Fig. ...
Citations
... It is also well known that the trachea is one of the organ, which has animal species difference for drug reaction [11,19]. We have continued research on the agents related to signal transduction of cAMP and cGMP in bovine and porcine smooth muscle [6][7][8][9]. ...
... In the bovine trachea, cAMP content was measured by enzyme immunoassay, as reported previously [7]. The trachea was incubated with imidazole (300 µM) or vehicle for 10 min. ...
The mechanism of imidazole-induced contraction on the bovine tracheal smooth muscle was investigated. Imidazole induced muscle contraction in a concentration-dependent manner on bovine, porcine and guinea-pig tracheas, but not in rat or mouse. In bovine tracheas, imidazole was cumulatively applied and induced muscle tension and increasesd intracellular Ca2+ level in a concentration -dependent manner. Imidazole, even at 300 μM, the concentration at which maximum contractile response occurs, did not significantly increase in cAMP content relative to control. Atropine inhibited imidazole-induced contraction at a concentration- dependent manner and pretreatment of hemicholinium-3 almost abolished imidazole-induced contraction. Conversely, pretreatment of tripelennamine, indomethacin or tetrodotoxin did not affect imidazole-induced contraction. Acetylcholine or eserine induced contraction in bovine, porcine, guinea pig, rat and mice trachea in a concentration -dependent manner. However, there was little difference in the rank order of maximum contraction of these agents. Imidazole-induced contraction was greater in bovine trachea compared to the other species tested. Further, cAMP did not appear to play a role in imidazole- induced contraction, suggesting other mechanisms, such as the release of endogenous acetylcholine.
