Effects of calcitonin gene-related peptide on food intake.

Recently, calcitonin gene-related peptide (CGRP), a product of alternative processing of RNA transcripts from the calcitonin gene, has been characterized. CGRP is present in a number of areas of the brain involved in modulating ingestive behaviors. We tested the effect of centrally administered CGRP on ingestive behaviors. ICV CGRP over a dose range of 1 to 10 micrograms suppressed food intake in 24 hr deprived rats and 20 and 10 micrograms decreased spontaneous nocturnal food intake. CGRP was less effective than calcitonin at suppressing food intake. Peripheral CGRP was less effective than centrally administered CGRP. Behaviorally, CGRP treated animals rested more, groomed less and ate less. Central CGRP (10 micrograms) did not alter circulating glucose levels. These results suggest that CGRP in high doses may be centrally active in regulating consummatory behaviors.