(-)threo-chlorocitric acid decreases sham feeding of sucrose in rats

The contribution of changes in rate of gastric emptying to the anorectic effect of (-)-threo-chlorocitric acid (chlorocitrate) was assessed by examining the effect of this drug in sham feeding rats, a preparation where gastric distention does not occur. Gavage administration of chlorocitrate (100-400 mg.kg-1) decreased sham and real feeding of 20% sucrose in a dose-related manner. In sham-feeding rats, the minimal effective dose was 200 mg.kg-1. The anorectic effect was evident at 60 min after 200 mg.kg-1 and 30 min after 400 mg.kg-1. In real-feeding rats, the minimal effective dose was 100 mg.kg-1 and for all doses tested the effect was apparent at the 15-min time point. In a second experiment, the effect of chlorocitrate (100-400 mg.kg-1) on gastric emptying of 20% sucrose was examined. Chlorocitrate (200 and 400 mg.kg-1) had a modest but significant inhibitory effect on gastric emptying; however, the effect was not dose-related. Inasmuch as chlorocitrate decreased sham feeding, its anorectic effect cannot be solely attributed to inhibition of gastric emptying. However, because chlorocitrate was more potent in the real-feeding condition relative to sham feeding, and the time course of the response in the two feeding conditions was different, part of chlorocitrate's anorectic effect may depend on postingestive cues such as gastric distention.