اثرات كربنوكسولون به عنوان مهار كننده كانال هاي GAP JUNCTION بر پاسخ هاي انقباضي عضلات صاف احشايي

The Effects of Carbenoxolone (a gap junction uncouples) on the Contractile Responses of the Isolated Rat vas Deferens.

the isolated rat colon and the isolated guinea pig ileum were studied. The main purpose of this study was to elucidate the possible involvement of gap junction channels (GJCs) in smooth muscle function. Carbenoxolone (0.1-200 µM) decreased contractile responses of the isolated rat vas deferens and colon to various stimuli in a concentration-dependent manner. Carbenoxolone also reduced both amplitude and frequency of the spontaneous mechanical activity of the isolated rat colon. A similar inhibitory effect of carbenoxolone (0.1-200 µM) was observed on contractile responses of the isolated guinea pig ileum to electrical field stimulation, acetylcholine and KCI. In the presence of carbenoxolone (10 1iM), contractile responses to L-NAME were reduced by about 65% and 80% of control in the isolated rat colon and the isolated guinea pig ileum, respectively. The present data, therefore, suggest an important role for modulation of intercellular communication via GJCs in regulating the tone of smooth muscles of rat vas deferens, rat colon and guinea pig ileum.