J. Geibel et al., GASTRIN-STIMULATED CHANGES IN CA2-CELLS DEPENDS ON ADENOSINE 3',5'-CYCLIC-MONOPHOSPHATE LEVELS( CONCENTRATION IN PARIETAL), Gastroenterology, 109(4), 1995, pp. 1060-1067
Background & Aims: The parietal cell has secretory receptors for hista
mine and acetylcholine, whereas the functional nature of the gastrin/c
holecystokinin B receptor is controversial. This study in isolated gas
tric glands investigates the cholecystokinin B receptor-induced intrac
ellular calcium concentration ([Ca](i)) response in enterochromaffin-l
ike (ECL) and parietal cells as a function of adenosine 3',5'-cyclic m
onophosphate pathways. Methods: The responses of [Ca](i) in ECL and pa
rietal cells of perfused rabbit or rat calcium orange-loaded gastric g
lands were determined using confocal microscopy. ECL cells were identi
fied by position, size, and autofluorescence and parietal cells by pos
ition and size. Results: Gastrin (1 mu mol/L) produced an elevation of
[Ca]i levels in both ECL and parietal cells. In the presence of 100 m
u mol/L cimetidine, the ECL cell response to gastrin was not affected
but the [Ca](i) response of the parietal cell was abolished. With dibu
tyryl adenosine 3',5' phosphate in addition to cimetidine, the respons
e of the parietal cell [Ca](i) to gastrin was restored in both the rat
and rabbit. Conclusions: The [Ca](i) response of the parietal but not
the ECL cell to the addition of gastrin seems to depend on the presen
ce of normal or elevated intracellular adenosine 3',5'-cyclic monophos
phate levels. Therefore, H-2 receptor activity may be permissive for t
he effect of gastrin on parietal cell function.