The Effect of I.C.I. 50,123 (Pentapeptide) on Acid Secretion in Man

Abstract

The effect of I.C.I. 50,123 (pentapeptide) on acid secretion in man was investigated in 36 patients. It is presumed that continuous intravenous infusion of I.C.I. 50,123 (pentapeptide) in a dose of 0.1 μg/kg/minute produces maximal acid output. Administration of a larger dose sometimes causes decrease in acid production. I.C.I. 50,123 (pentapeptide) administered intravenously in a dose of 0.1 μg/kg/minute produces approximately the same acid output as does histamine given intravenously in a dose of 0.7 μg/kg/minute. In most cases maximal acid output after infusion of I.C.I. 50,123 (pentapeptide) occurs in the second 15-minute period. After histamine maximal acid output is attained a little later—in the third or fourth 15-minute period. Side-effects after intravenous administration of I.C.I. 50,123 (pentapeptide) were in only one case of such severity that the test had to be broken off. It is concluded that I.C.I. 50,123 (pentapeptide) given intravenously in a dose of 0.1 μg/kg/minute is adequate for evaluation of the maximal acid output in man.

Index-words:

• Stomach
• gastric juice
• gastrin
• gastric acidity determination