| Abstract: | Conditioned taste aversion to threshold and suprathreshold concentrationsof sodium chloride, sucrose, and other sweeteners was measuredin obese and lean female Zucker rats. In the first experiment0.1M sodium chloride, 0.1M sucrose, or water was paired witha constant dosage of apomorphine hydrochloride (6.72 mg IP foreach rat). The magnitude of conditioned aversion to sucrose(0.1M and 0.316M) and sodium chloride (0.1M and 0.316M) followingthe initial conditioning trial was similar for obese and leanrats. However, repeated cycles of conditioning and extinctiontrials resulted in decreased sucrose intakes for obese ratsand increased sucrose intakes for lean rats. No changes in intakeoccurred with sodium chloride. In the second experiment 0.1M sucrose or water was paired withdoses of apomorphine hydrochloride based on each rat's bodyweight (30 mg/kg IP). The magnitude of aversion to sucrose (0.01M,0.0316M, 0.1M, 0.316M) and other sweetners (0.75M glucose, 0.1Msucrose, 0.001M sodium saccharin, and 0.025M sodium cyclamate)were similar for obese and lean rats. These data suggest thatrepeated testing with sucrose, rather than differences in sensorytaste factors, contributes to the previous reports of decreasedintake and sweet preference of obese rats. |
