A Comparison of Isomers and Congeners of Phenylpropanolamine (PPA) and Norpseudoephedrine on Gastric Retention and Food Intake in Rats

Program year: 1996/1997Digitized from print original stored in HDRThe purpose of this study was to compare the action of various drugs on gastric retention (Experiment 1) and food intake (Experiment 2). The subjects were 79 Sprague-Dawley male albino rats. (Experiment 1 = 40), (Experiment 2 = 39). In Experiment 1, the rats consumed a pellet meal and were then injected (IP) with saline or either (30 mg/kg) of l-PPA, d-PPA, 1- norpseudoephedrine or d-norpseudoephedrine. The rats treated with saline, d-norpseudoephedrine, l-norpseudoephedrine and d-PPA exhibited a marked clearance of food. The rats treated with 1- PPA detained a large portion of the test meal, indicating that 1- PPA is indeed effective in the inhibition of gastric emptying. In Experiment 2, the rats were first injected (IP) with saline or either (30 mg/kg) of l-PPA, d-PPA, l-norpseudoephedrine or dnorpseudoephedrine. After injection, the rats consumed a pellet meal. The rats treated with d-PPA exhibited a normal amount of grams consumed. The rats treated with l-norpseudoephedrine and d-norpseudoephedrine displayed a small but not significant decline in food intake. The l-PPA drug group demonstrated a significant reduction in food intake. This data concludes that l-PPA is not only effective in gastric inhibition, but effective in the reduction of food intake and that the former may mediate the latter as well