Effect of adding albumin to solutions of secretin on pancreatic volume and bicarbonate response.

In six conscious dogs with gastric and pancreatic Thomas fistulas, we studied the pancreatic bicarbonate response to intravenous bolus injections of synthetic secretin dissolved either in 5 ml of 0.15 M NaCl alone or in the same amount of NaCl to which dog albumin had been added, to give a 0.1% solution. The pancreatic bicarbonate (micromol . 10 min-1) response to the four lowest doses of secretin (12.5, 25, 50, 100 ng . kg-1) used was significantly (p less than 0.05) higher when secretin was dissolved in NaCl plus albumin than in NaCl alone. The pancreatic response to higher doses of secretin (200, 400, 800, 1600 ng . kg-1) was not significantly altered by the addition of albumin. The D50 of secretin was about 2.6 times greater in the absence than in the presence of albumin. This study suggests that albumin should be added to dilute solutions of secretin to preserve biological activity.