Chronic central versus peripheral ouabain, blood pressure, and sympathetic activity in rats. Hypertension 23: 1087–1090

Abstract To assess whether chronic ouabain administration causes hypertension by increasing sympathetic activity, we recorded arterial blood pressure and heart rate at rest and after ganglionic blockade in conscious Wistar rats following 10 to 14 days of central or peripheral administration of ouabain. Intracerebroventricular or intravenous infusion of ouabain (10 fig/d for both) as well as subcutaneous ouabain pellets (releas-ing 25 fig ouabain/d per pellet) increased mean arterial pressure by 20 to 30 mm Hg and heart rate by 40 to 60 beats per minute. Ouabain pellets increased blood pressure and heart rate in a dose-related manner. After 2 weeks of all ouabain treatments, ouabainlike activity in plasma was not changed but increased significantly in hypothalamus and adre-nals. Ouabainlike activity in the adrenals was increased more The relation between high sodium intake andhypertension in salt-sensitive hypertensive ratsis complex and not yet understood. We hav