Gastrin potentiates histamine-stimulated aminopyrine accumulation in isolated rat parietal cells.
Rat gastric mucosal cells, containing 25-35% parietal cells, were obtained by a modified isolation procedure involving protease, ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid, and mechanical treatments. Parietal cell responsiveness to secretagogues was assessed by the accumulation of the weak base [14C]aminopyrine in intracellular acidic compartments. Histamine, without phosphodiesterase inhibitors, dose dependently stimulated aminopyrine accumulation with an effective concentration producing 50% of maximal response of 13 microM and a maximal effective dose of 100 microM. Pentagastrin and rat gastrin-17 alone were ineffective but potentiated dose dependently the action of 100 microM histamine. The mean potentiating effect varied from 32 to 70% for 100 nM pentagastrin and from 36 to 95% for 100 nM rat gastrin-17. Pentagastrin (100 nM) also potentiated the effect of 1 mM dibutyryladenosine 3',5'-cyclic monophosphate (cAMP) by 44%, but it did not increase further the stimulation by carbachol. The potentiating effect of pentagastrin on histamine- and dibutyryl cAMP-stimulated aminopyrine accumulation was also observed after enrichment of parietal cells to 65-85%. The endogenous histamine was insufficient to stimulate acid production. Therefore gastrin appears to have a direct action also in rat parietal cells.
Cabero
J L
JL
Department of Medical and Physiological Chemistry, Uppsala University, Sweden.
Li
Z Q
ZQ
Mårdh
S
S
D000632:Aminopyrine / Q000378:metabolism*; D000818:Animals; D003994:Bucladesine / Q000378:metabolism; D005753:Gastric Mucosa / Q000166:cytology / Q000378:metabolism; D005755:Gastrins / Q000494:pharmacology*; D006632:Histamine / Q000378:metabolism / Q000494:pharmacology*; D009994:Osmolar Concentration; D010295:Parietal Cells, Gastric / Q000378:metabolism*; D051381:Rats
D005755:Gastrins; D000632:Aminopyrine; D003994:Bucladesine; D006632:Histamine