Differential effects of the kappa opioid receptor on the melanocortin antagonist agouti-related protein
Williams, Sara Elizabeth
MetadataShow full item record
This study investigated the effects of Nor-BNI co-administered and administered 24h after AgRP into the lateral ventricle (ICV) and the 3rd ventricle on AgRP induced feeding. Male Sprague Dawley rats were fitted with ICV or 3rd ventricle cannulas, then injected with 1nmol AgRP followed by 6.3nmol Nor-BNI co-administered or administered 24h after AgRP. Lateral ventricle Nor-BNI co-administered with AgRP significantly suppressed AgRP induced feeding at 24 h (p=0.0001). Lateral ventricle Nor-BNI administered 24h after AgRP showed no significant effect on AgRP induced feeding at any time point. 3rd ventricle Nor-BNI co-administered with AgRP significantly reduced sustained AgRP induced hyperphagia at 6, 24, 48, and 72h. 3rd ventricle Nor-BNI injected 24h after AgRP significantly reduced food intake at 48h after Nor-BNI injection compared to AgRP (p=0.026). These results along with prior research suggest that [nu]-opioid receptors may be involved in the prolonged feeding intake of AgRP in the 3rd ventricle.