Effects of Gastrin-releasing Peptide_(1-27) on Taste Responses in the Rat

摘要

Gastrin-releasing-peptide_(1-27) (GRP) has been implicated in the regulation of satiety and appetite in numerous paradigms. However, the specific site and mode of action of this gut-brain peptide has not been elucidated. The following experiment examined the effects of GPR on taste responses to sucrose in the behaving rat. A brief-exposure, multi-bottle gustometer was used to provide rats with momentary access to six different ocncentrations of sucrose in a single test session. This procedure has been used previously, resulting in monotonically increased licking behavior as concentrations of sucrose increase. Differing injection procedures were employed such that rats were tested immediately after i.p.injection or 5 min after i.p.injection of 5 nmol/kg body wt of GRP. Results indicate that GRP does reduce the oral reinforcing properties of socrose, but the effect is transient, diminishing significantly within 5 min after injection.