Intracerebroventricular beta-endorphin increases food intake of rats☆

Abstract B-Endorphin (B-END), met-enkepalin (M-ENK), and DAla 2 NMe 5 -met-enkephalinamide were administered intracerebroventricularly to rats and effects on the ingestion of a liquid diet were examined. B-END significantly increased food intake in a half-hour test at a dose of 200 ng/rat. Lower or higher doses did not affect food intake. Neither M-ENK or the synthetic enkephalin analog affected ingestion of the liquid diet. These findings demonstrate rapid action of an endorphin on food intake administered at a lower dose than has previously been reported and suggest a specificity for B-END in the endorphinergically mediated hyperphagic response.