Two different types of electrogenic amino acid action on pancreatic acinar cells.

The electrogenic action of the basic amino acid, L-arginine, has been compared with the action of the neutral amino acids, L-alanine and glycine, in mouse pancreatic acinar cells. All three amino acids cause membrane depolarization, but while the reversal potential for the action of the neutral amino acids is close to the calculated value of the Na equilibrium potential (+30 mV) the reversal potential for the L-arginine effects is +7 mV. The neutral amino acids exhibit mutual inhibition, but L-arginine did not inhibit the L-alanine- or glycine-evoked depolarization nor did the neutral amino acids inhibit the action of L-arginine. While L-alanine markedly depressed acetylcholine-evoked depolarization, L-arginine had no such effect. It is concluded that there are at least two quite different types of electrogenic amino acid action in pancreatic acinar cells.