The effects of L-alanine and acetylcholine on membrane potential, 45Ca2+ and 86Rb+ efflux and amylase secretion in the isolated mouse pancreas.
A comparative study was made of the effects of acetylcholine (ACh) and the neutral amino acid L-alanine on membrane potential, 45Ca2+ and 86Rb+ fractional efflux, and amylase secretion in segments of the isolated mouse pancreas. Both ACh and L-alanine evoked similar dose-dependent depolarizations of pancreatic acinar cells. ACh, but not L-alanine, caused a marked reduction in input resistance and evoked electrical uncoupling of acinar cells at high concentrations. Measurements of 45Ca2+ release from pre-labelled tissue showed that ACh increased the fractional efflux of 45Ca2+ whereas L-alanine had no such effect. Both ACh and L-alanine stimulated the release of 86Rb+ from pre-labelled tissues. The L-alanine-evoked 86Rb+ efflux was markedly reduced by pre-treatment with 10(-3) M ouabain which had no effect on the ACh-induced response. L-alanine had no significant effect on amylase secretion whereas ACh elicited a marked increase in amylase output. These results show that although both ACh and L-alanine evoke depolarization of the pancreatic acinar cell membrane, the mechanisms underlying their actions on the cells are different.
D000109:Acetylcholine / Q000494:pharmacology*; D000409:Alanine / Q000494:pharmacology*; D000681:Amylases / Q000378:metabolism*; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002132:Calcium Radioisotopes; D066298:In Vitro Techniques; D008564:Membrane Potentials / Q000187:drug effects; D051379:Mice; D010179:Pancreas / Q000378:metabolism*; D011868:Radioisotopes; D012413:Rubidium / Q000378:metabolism*
D002132:Calcium Radioisotopes; D011868:Radioisotopes; D000681:Amylases; D012413:Rubidium; D000109:Acetylcholine; D000409:Alanine; D002118:Calcium