Abstract
Smooth muscle cells isolated separately from the caecal circular smooth muscle layer of the guinea pig were used to investigate whether corticotropin releasing hormone (CRH) can inhibit directly the contraction produced by cholecystokinin octapeptide (CCK-8). In addition, the role of adenylate cyclase and guanylate cyclase in the direct inhibitory effect of CRH was examined. CRH inhibited the contractile response produced by 10 −9M CCK-8 in a concentration-dependent manner, with an IC 50 value of 0.16nM. An inhibitor of particulate guanylate cyclase and an inhibitor of soluble guanylate cyclase had no significant effect of the relaxation produced by CRH. In contrast, an inhibitor of adenylate cyclase and an inhibitor of cAMP-dependent protein kinase significantly inhibited the ralaxation produced by CRH. This is the first report demonstrating the direct inhibitory action of CRH on the isolated caecal smooth muscle cells via adenylate cyclase system.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call