A procedure for within-trial repeated measurement of gastric emptying in the rat.

A double sampling procedure, developed originally for investigation of liquid phase gastric emptying in humans, is adapted for use in the rat. The double sampling technique permits repeated measurement of gastric volume, allowing a determination of a time course of emptying in a single experimental session. Further, the method allows determination of the amount of gastric secretion, volume emptied into the intestines, and amount of initial gastric load remaining in the stomach. Experiments are presented which: demonstrate the utility of the technique; validate its accuracy in determining gastric volume; indicate the stability of measurements obtained with this procedure; and indicate a procedure for quantitative evaluation of data obtained with this technique. The limitations of the double sampling method are also discussed.