Intracerebroventricularly administered pertussis toxin blocks the central vasopressor action of neuropeptide Y(13-36) in the awake unrestrained male rat.

The effects of intracerebroventricular (i.v.t.) injections of pertussis toxin (PTX) (10 micrograms/30 microliters, 48 h) were studied on the cardiovascular actions of i.v.t. administered neuropeptide Y(13-36) (NPY(13-36)) as evaluated in the awake unrestrained male rat. The vasopressor action of NPY(13-36) in the peak dose of 3000 pmol per rat was significantly inhibited by pretreatment by PTX. Pertussis toxin treatment alone significantly reduced the baroreceptor reflex elicited by L-phenylephrine. The results are compatible with the view that G-proteins mediate the central vasopressor actions of NPY(13-36) and thus probably are involved in NPY Y2-receptor transduction in cardiovascular areas of the brainstem.