Central cardiovascular effects of nylidrin (buphenine)

The injection of small doses of nylidrin into the vertebral artery lowered blood pressure in chloralose-anesthetized cats. Cerebroventricular perfusion of nylidrin also decreased blood pressure and inhibited or modified cardiovascular reflexes. There was inhibition of the reflex bradycardia evoked by i.v. noradrenaline or angiotensin. Likewise the pressure increase due to bilateral carotid occlusion was diminished. The blood pressure decrease elicited by stimulation of the central stump of a cut vagus nerve was inhibited or reversed. The pattern of central cardiovascular effects of nylidrin seemed not compatible with its well known beta-sympathomimetic properties. Indirect evidence points to an interasction with central alpha-receptors.