Comparison of Synthetic and Natural Porcine Secretios on Human Pancreatic Secretion

Abstract

Abstract The effect of graded intravenous doses of synthetic porcine secretin (Squibb Institute for Medical Research, Princeton, N. J.) and natural porcine secretin (GIH, Karolinska Institutet, Stockholm, Sweden) on pancreatic secretion was examined in 6 healthy male subjects. Pancreatic secretion was also studied in 3 subjects after subcutaneous synthetic secretin. Calculated maximal response of bicarbonate output and secretin dose for one-half maximal response (D 50 ) were calculated for both synthetic and natural secretins from the means of the dose-response data. The dose-response curves with synthetic secretin and natural secretin were superimposable for: volume, bicarbonate concentration, and bicarbonate and protein output. The observed and calculated maximal responses for bicarbonate secretion were not significantly different between the two secretins. Subcutaneous synthetic secretin increased pancreatic secretion above basal for 3 hr. It was concluded that in man: (1) synthetic secretin and natural porcine secretin were of equal efficacy for bicarbonate secretion; (2) 1 µg of synthetic secretin was equivalent to approximately 3.86 U of natural secretin; (3) subcutaneous synthetic secretin was an effective stimulant of pancreatic bicarbonate secretion; (4) synthetic secretin was free of any observed side effects.