A pattern for gastric emptying in mice.

Gastric emptying was studied in CD-1 mice weighing 15-30 g. Mice were fed a nonabsorbable test meal consisting of radioactive barium sulfate suspended in 1.5% methylcellulose. The amount of test meal remaining in the stomach was determined 1, 2, 5, and 10 min after the administration. The initial rates of emptying were significantly higher in the groups weighing 15-20 g body wt. In all groups, 50% of the radioactivity administered was emptied in less than 5 min. The gastric emptying figures obtained were adjusted to three general equations: exponential, hyperbolic, and parabolic. The best correlation coefficients were obtained with the parabola, although this pattern of emptying is not completely satisfactory because it has a minimum before the 10th min. The comparison of the exponential and hyperbolic patterns, in terms of both the correlation coefficients and the "starting indexes," showed that the hyperbola describes the data more closely. No sex differences were observed.