Cardiovascular actions of central neuropeptide W in conscious rats

Neuropeptide W (NPW) is a novel hypothalamic peptide that activates the orphan G protein-coupled receptors, GPR7 and GPR8. Two endogenous molecular forms of NPW that consist of 23- and 30-amino acid residues were identified. Intracerebroventricular (i.c.v.) administration of NPW is known to suppress spontaneous-feeding at dark-phase and fasting-induced food intake and to decrease body weight and plasma growth hormone and to increase prolactin and corticosterone; however, little is known about its effect on other physiological functions. We examined the effects of i.c.v. administration of NPW30 (0.3 and 3 nmol) on the mean arterial pressure (MAP), heart rate (HR), and plasma norepinephrine and epinephrine in conscious rats. NPW30 (3 nmol) provoked increases in MAP (85.12+/-3.16 to 106.26+/-2.66 mm Hg) and HR (305.75+/-13.76 to 428.45+/-26.82 beats/min) and plasma norepinephrine (138.1+/-18.1 to 297.2+/-25.9 pg/ml) and epinephrine (194.6+/-21.4 to 274.6+/-22.7 pg/ml). Intravenously administered NPW30 (3 nmol) had no significant effects on MAP and HR. These results indicate that central NPW30 increases sympathetic nervous outflow and affects cardiovascular function.