Effect of temperature of perorally administered phenol red solution on gastric emptying in the rat.

Phenol red solutions of 5,25 and 45 degress C were administered perorally to rats. 15, 30 and 45 min after administration the rats were sacrificed and the residue of phenol red in the stomach and in the small intestine determined. Precent phenol red dose recovered from the stomach versus time was found to follow first-order kinetics. The data show a decrease of gastric emptying with increasing temperature of the phenol red solution administered.