NPY-Y1 receptor antisense injected centrally in rats causes hyperthermia and feeding

The central actions of neuropeptide Y antisense oligodeoxynucleotide (aNPY) and NPY-Y1 receptor antisense (aNPY-Y1) on body temperature (Tb), feeding and body weight of unrestrained rats were determined by the repeated intracerebroventricular (i.c.v.) injection of 0.5 microgram doses. aNPY-Y1 caused intense phasic rises in Tb, lowered body weight and caused transient feeding. aNPY increased food intake paradoxically, accompanied by a gain in body weight but did not affect Tb. Circadian activity was unaffected by either antisense oligodeoxynucleotide, and the mismatched NPY (mNPY) was without effect. These results show that NPY-Y1 receptors underlie the central thermolytic action of NPY, since aNPY-Y1 induces hyperthermic responses. Overall, the functional reduction in NPY activity by aNPY might cause a compensatory de novo synthesis of NPY in structures remote from the ventricles to augment feeding behavior.