Both carbachol (10(-4)-10(-3) mol/l) and cholecystokinin octapeptide (CCK-8) (10(-8)-10(-6) mol/l) significantly stimulated the release of pepsinogen from rabbit gastric mucosa maintained in organ culture (213-216% and 143-261% of control, respectively, p less than 0.05-0.01). The secretion was not affected by removing Ca2+ from the culture medium with ethylene glycol tetra-acetic acid. Verapamil failed to inhibit the secretion of pepsinogen induced by the drugs in ordinary culture medium containing Ca2+. In contrast, nicorandil (10(-6)-10(-4) mol/l) attenuated the release of pepsinogen by the drugs in a dose dependent manner, regardless of the presence or absence of Ca2+ in the culture medium. W-7 (10(-6)-10(-4) mol/l) and W-5 (10(-5) and 10(-4), or 10(-6) mol/l) reduced significantly the secretion of pepsinogen induced by carbachol (53-71% and 63-81% of control, respectively, p less than 0.05-0.01) and that by CCK-8 (49-67% and 66-76% of control, respectively, p less than 0.01) in the Ca2+ containing medium. However, W-7 did not show significant inhibition of cyclic adenosine monophosphate (cAMP) and forskolin induced pepsinogen secretion. These findings indicate that the calmodulin messenger branch that is activated by a rise of intracellular Ca2+ mobilised in cytosol from its intracellular, but not extracellular, source plays a critical role in pepsinogen secretion induced by carbachol and CCK-8. It seems likely that an increase in cAMP in cytosol does not provoke any calmodulin mediated pepsinogen secretion.
Statistics from Altmetric.com
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.