Effects of secretagogues on oxygen consumption, aminopyrine accumulation and morphology in isolated gastric glands

Abstract

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: 1) Respiratory activity; 2) Intraglandular accumulation of the weak base aminopyrine; 3) Quantitative morphology of the parietal cells. The following substances were tested: Histamine, 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, however, not of the same magnitude as after db-cAMP. Aminophylline, tested only for respiratory activity, stimulated the oxygen consumpation moderately. Carbachol induced a transient increase in both the oxygen consumption and in the aminopyrine accumulation with a peak value after approximately 15 minutes for both, but gave no significant morphological alterations. Pentagastrin, finally, was incapable of inducing changes in any of the three parameters. Aminopyrine was also found to accumulate approx. 50 times in unstimulated, morphologically resting glands. This seems to indicate that there might be acid sites already in resting glands.