Effect of amino acids on H+ production by isolated rat parietal cells.
We investigated the hypothesis of a direct effect of amino acids on gastric parietal cells. [14C]aminopyrine uptake into isolated enriched rat parietal cells served as a quantitative index of H+ production. Cells were incubated in media containing 1 mM Ca2+ in the absence or presence of the phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine (IBMX), or 3 mM Ca2+ without IBMX. Under these different conditions, L-arginine, L-phenylalanine and L-tryptophan (10(-6) M to 3 X 10(-2) M) failed to alter basal [14C]aminopyrine uptake as well as the response to submaximal stimulation by histamine, forskolin, N6O2-dibutyryladenosine-3',5'-(cyclic)-phosphate (db cAMP) or carbachol. Pentagastrin failed to elicit an appreciable response in the presence and absence of 10(-3) M of all three amino acids studied. It is concluded that in vivo the potent stimulation of gastric acid secretion by L-arginine, L-phenylalanine and L-tryptophan is mediated by other than direct mechanisms.
Schmidtler
J
J
Department of Internal Medicine II, Technical University of Munich, FRG.
Schepp
W
W
Schusdziarra
V
V
Classen
M
M
D000596:Amino Acids / Q000502:physiology*; D000632:Aminopyrine / Q000493:pharmacokinetics; D000818:Animals; D005260:Female; D005744:Gastric Acid / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D010295:Parietal Cells, Gastric / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains
D000596:Amino Acids; D000632:Aminopyrine