CARDIOVASCULAR ACTIONS OF NEUROPEPTIDE-Y AND SOCIAL STRESS

The role of central neuropeptide Y (NPY) in the cardiovascular respons e to social stress was evaluated in freely moving rats using telemetry . In unstressed rats, intracerebroventricular (ICV) administration of NPY and the selective Y-1 receptor agonist [Leu(31), Pro(34)]-NPY decr eased blood pressure and heart rate, while the selective Y-2 agonist N PY13-36 transiently raised blood pressure. NPY and [Leu(31),Pro(34)]-N PY blunted elevations in blood pressure and pulse rate following expos ure to the resident-intruder procedure, an established social stress p aradigm. In contrast, the Y-2 agonist significantly augmented stress i nduced presser effects. These observations indicate that the hypotensi ve effects of ICV NPY appear to be mediated by the Y-1 receptor subtyp e and the NPY receptor subtypes may mediate opposing cardiovascular ac tions in response to stressful stimuli. (C) 1998 Elsevier Science Inc.