Abstract
The effect of secretin and pancreozymin on the secretion of electrolytes and enzymes into the duodenum has been studied in human subjects. The reproducibility of the response to secretin alone and to secretin plus pancreozymin was excellent, providing a period of about one month was allowed to elapse between tests. With short intervals between tests, some subjects showed marked ‘hypersensitivity’ to low doses of secretin. Pancreozymin (16 units per kg each hour) combined with a barely suprathreshold dose of secretin (0.25 units per kg each hour) elicited a bicarbonate response as great as the response to a high dose rate (4 units per kg each hour) of secretin alone. The potentiation involved a change in the mechanism of secretion of bicarbonate, since the chloride response to the combination of hormones was significantly less than the chloride response to secretin alone.