A role for central glucagon-like peptide-1 in temperature regulation

We have already established that central glucagon-like peptide-1 (GLP-1) has a role in the central control of food intake. In this study, experiments were conducted to establish the effect of acute intraperitoneal (i.p.) and intracerebroventricular (i.c.v.) administration of GLP-1 on temperature. Injection of 10 micrograms GLP-1 i.c.v. caused a significant reduction in temperature over the subsequent 2 h and reduced food intake as expected. Both effects were blocked by prior i.c.v. administration of the GLP-1 antagonist exendin 9-39 at a ratio of 30:1. Administration of 300 micrograms GLP-1 i.p. also reduced temperature over the 2 h following injection but had no effect on food intake. Administration of exendin 9-39 alone by the i.c.v. route had no effect on temperature. These results indicate that GLP-1 is a neuropeptide involved in the regulation of temperature. Furthermore, the mechanisms that mediate the effect on temperature may be different from those regulating food intake given the effect on temperature but not food intake of i.p. GLP-1.