Inhibitory Mechanism of Papaverine on Carbachol-Induced Contraction in Bovine Trachea

Abstract

Abstract. We have demonstrated that the relaxing mechanism of papaverine in phasic muscles such as ileum, urinary bladder, and uterus is different from tonic muscles such as aorta. In this study, we examined the inhibitory mechanism of papaverine on carbachol ( ] i level induced by papaverine or dibutyryl-cAMP. These results suggested that the relaxing mechanism of papaverine in the bovine trachea is mainly due to increases of cAMP content by inhibiting phosphodiesterase and the mechanism is partially involved in the activation of BK channel by cAMP.

Effect of essential oil of Anthemis mauritiana Maire & Sennen flowers on intestinal smooth muscle contractility

“…It causes relaxation by multiple mechanisms, but mainly via the intracellular accumulation of cAMP and/or cGMP, by inhibiting phosphodiesterase, by having effects on Ca ++ movement and inhibition of mitochondrial respiration, although in ileal smooth muscle it is largely due to the last mechanism (Kaneda et al, 1998(Kaneda et al, , 2005. Thus the inhibitory effect of EOAM on the carbachol concentration-response was like a noncompetitive antagonism attenuating the maximum response (Hajhashemi et al, 2000;Gilani et al, 2005).…”

Effects of Papaverine on Twitches in Mouse Diaphragm

“…In the muscle strips, cAMP and cGMP contents were measured by enzyme immunoassay as reported previously [11] . After the muscles had been electrically stimulated for 5 min, papaverine or 3-isobutyl-1-methylxanthine (IBMX) was added to the organ bath for 20 min.…”

“…Although these different mechanisms have been proposed, efforts to compare and evaluate the 3 concepts in various smooth muscles have been neglected.We recently reported that papaverine inhibits smoothmuscle contraction mainly by the accumulation of cAMP and/or cGMP due to the inhibition of PDE in tonic muscle, such as rat aorta [10] and bovine trachea [11] , but by inhibiting mitochondrial respiration in phasic muscle, such as guinea pig ileum [10] , urinary bladder [12] and rat uterus [13] . Based on these studies, we have proposed that the mechanism by which papaverine causes relaxation is related to the accumulation of cAMP and/or cGMP contents in tonic muscles and inhibition of mitochondrial respiration in phasic muscles.…”

Ibudilast-Induced Decreases in Cytosolic Ca2+ Level and Contraction in Rat Aorta

“…In the muscle strips, cAMP or cGMP content was measured by enzyme immunoassay as reported previously (11). The muscles were incubated with PE (1 µM) for 15 min, and then ibudilast or 3-isobutyl-1-methylxanthine (IBMX) was added and incubation continued for 10 min.…”