Effect of viscosity of test meals on gastric emptying in dogs.

In five dogs gastric emptying of low, medium and high viscosity meals was measured via a duodenal cannula. The rate of emptying depended on the viscosity of the test meals: the time for half emptying was 4.5 +/- 2.2 min with the low viscosity liquid meal (1 centipoise), 28.9 +/- 9.5 min with the test meal of medium viscosity (10(5) centipoise), and 43 +/- 11.8 min with the test meal of high viscosity (10(6) centipoise). The emptying curves of the medium and high viscosity meals were sigmoid, whereas the curve representing the emptying of the low viscosity liquid meal followed an exponential pattern. Results indicate that the viscosity of the meal is an important factor for the rate of gastric emptying.