H+ production by isolated cells from human gastric mucosa

Gastric mucosal cells were isolated from human mucosa obtained at surgery. H+ production was indirectly estimated by 14C aminopyrine (AP) uptake. The maximal response to histamine occurred after 30 min of incubation whereas intrinsic factor (IF) secretion was maximal after only 7.5 to 15 min. According to the concentration response curve 10(-4) mol/1 histamine proved to be the most effective concentration, the response to which was completely inhibited by ranitidine. Carbachol, dibutyryl cAMP and IMX also enhanced AP uptake, IMX being even more powerful than histamine. Carbachol and IMX failed to potentiate the response to histamine. Parietal cell fractions enriched by a Percoll density gradient revealed a pronounced background stimulation so that additional stimulation by test agents was less effective than in non-fractionized cells.