EFFECTS OF SECRETAGOGUES ON OXYGEN-CONSUMPTION, AMINOPYRINE ACCUMULATION AND MORPHOLOGY IN ISOLATED GASTRIC GLANDS

A recently developed method to isolate gastric glands from the rabbit gastric mucosa (Berglindh and Obrink, 1976) was used to study the effects of some common gastric secretagogues. Three parameters were investigated: Respiratory activity; Intraglandular accumulation of the weak base aminopyrine; Quantitative morphology of the parietal cells. The following substances were tested: histamine cyclic AMP [cAMP], dibutyryl cAMP [db-cAMP], aminophylline, carbachol and pentagastrin. The strongest effect was obtained with db-cAMP which dose-dependently stimulated the respiration up to 200%, increased the aminopyrine accumulation 80% and altered the parietal cell morphology from a typically resting to a typically stimulated state. cAMP also stimulated the respiration but was about 10 times less effective on a molar basis than the dibutyryl form. Histamine, like db-cAMP, stimulated the respiration in a dose-dependent manner and strongly increased the aminopyrine accumulation. The morphological changes were not of the same magnitude as after db-cAMP. Aminophylline, tested only for respiratory activity, stimulated the O2 consumption moderately. Carbachol induced a transient increase in both the O2 consumption and in the aminopyrine accumulation with a peak value after approximately 15 min for both, but gave no significant morphological alterations. Pentagastrin was incapable of inducing changes in any of the 3 parameters. Aminopyrine also accumulated approximately 50 times in unstimulated, morphologically resting glands. There might be acid sites already in resting glands.