Centrally administered neuropeptide Y fails to increase food intake but enhances hypoalgesia in spontaneously hypertensive rats

Abstract The effects of intracerebroventricular (i.c.v.) administration of neuropeptide Y (NPY 1–36 ) on food intake and pain sensitivity in hot plate test were studied in spontaneously hypertensive rats (SHRs) and in normotensive Wistar-Kyoto (WKy) rats. In satiated SHRs NPY 1–36 failed to significantly increase intake at doses that produced a strong effect in satiated WKy rats (0.25–1.25 nmol). Conversely, both NPY 1–36 and the C-terminal fragment NPY 13–36 , a putative selective agonist for the Y 2 -receptor for NPY, enhanced the spontaneously occurring hypoalgesia of SHRs, having no effect in WKy rats. The present results indicate that the NPY central systems involved in the control of regulatory functions are differently tuned in SHRs and WKy rats, suggesting possible involvement of these systems in the genesis of hypertension.