Effects of intraventricular and intraspinal 6-hydroxydopamine on blood pressure of renal hypertensive rats.

6-Hydroxydopamine (6-OH-DA) was administered into the lateral brain ventricle of normal rats and of rats with renal hypertension produced by unilateral clipping of the renal artery, and was also administered into the spinal cord of normal rats. Intraventricular administration of 6-OH-DA prevented the development of renal hypertension in rats, but was ineffective in developed renal hypertension. The development of renal hypertension was not affected by pretreatment with intraspinal injection of 6-OH-DA, which produced a marked reduction only in spinal cord noradrenaline. These data suggest that brain adrenergic neurones may participate in the production of renal hypertension but the noradrenergic projections in the spinal cords are not essential for this process.