A Secretin Test with High Doses of Secretin and Correction for Incomplete Recovery of Duodenal Juice

Abstract

Summary The duodenal response to about 8 units per kilogram of secretin was studied in 15 normal cases and 12 pancreatic disease cases. The total flow of duodenal juice was calculated from the dilution of radioactive vitamin B 12 , which was continuously infused into the duodenum. The dead space of the duodenum and the tube was calculated and found to be, on an average, about 30 ml. The mean duodenal secretion recovered immediately after 1 unit per kilogram of secretin was 65 ml per 15 min, or equal to the response obtained by Agren et al. in 1935 to 1937. 17 The corresponding value for the corrected secretion was, on an average, 80 ml per 15 min. The corrected secretion increased to 124 ml per 15 min after further 7.5 units per kilogram and dropped to the volume obtained after one standard dose of secretin after 60 min. The average volume in the normals during 60 min, after the high dose of secretin, was 3.15 ml per kilogram. Corrections for intestinal losses and body weight decreased the coefficient of variation from 29 to 17%. The maximal bicarbonate concentration did not rise significantly above the values reported for 1 unit per kilogram of secretin. It was 110 mEq per liter with a standard deviation of 15. Signs of exhaustion of the bicarbonate secretion, reported for animal experiments, occurred during different parts of the experiment. The mean total bicarbonate secretion calculated per 60 min amounted to 0.509 mEq per kilogram. The standard deviation was 0.107 mEq per kilogram. The total amylase production during 60 min was, on an average, equal to the amylase amount obtained with the thousand times less potent preparation from the years 1935 to 1942. The range of the total amylase outputs in 60 min was much greater than that of the bicarbonate. The coefficient of variation was 41% after correction for weight and intestinal losses. Total Cryptic activity and total amounts of lipase varied between the same limits as in an earlier material from 1935 to 1942. The correlation between amylase, lipase, and total Cryptic activity was poor. Twelve cases of pancreatitis were investigated. Six cases with malabsorption showed a marked decrease in the bicarbonate secretion and in the enzymes assayed. Of the other 6, 3 had a reduction in the maximal bicarbonate concentration and total bicarbonate output during 60 min; 2 of the latter also had a decrease in the total tryptic activity during 30 min, and 1 had a decrease of amylase.