The kappa opioid receptor, ingestive behaviors and the obese mouse (ob/ob)

Recent studies have suggested a role for the kappa opiate receptor and its endogenous ligand, dynorphin, in the central regulation of appetite. In this study we found that the ob/ob mouse was mildly resistant to the ability of three kappa agonists, viz. butorphanol, tifluadom, and ketocyclazocine to induce food intake. In addition, we could find no change in ir-dynorphin levels in 7 areas for the central nervous system. These findings do not provide evidence for a role of kappa opioid feeding system in the pathogenesis of obesity in the ob/ob mouse.