Effect of exogen pentagastrin on mastocyte degranulation, gastric cAMP and intragastric pH in Shay rats.

: The degranulation of mastocytes, gastric cAMP and intragastric pH after the administration of 125 micrograms/kg exogen pentagastrin in Shay rats was studied. The results showed a decrease in the number of mastocytes in the gastric mucous membrane in the first hour analysed with a highly significant increase afterwards. There was a significant increase in the values of cAMP which corresponded to an acidification of intragastric pH. From these results it may be deduced that the increase in the release of histamine, as reflected by the decrease in the number of mastocytes, provokes the increase in the gastric levels of cAMP, which would in turn be responsible for the increase in the acid secretion provoked by the administration of exogen pentagastrin.