Physiological significance of Na+/K(+)-ATPase activity in the central nervous system and endogenous sodium-pump inhibitors in the neural regulation of arterial blood pressure.

In anesthetized Sprague-Dawley rats, cerebrolateral ventricular administration of potassium chloride solutions (KCl, 0.375-1.25 μmol, i.c.v.) produced concentration-dependent reductions in the arterial blood pressure and heart rate. These responses were significantly attenuated by prior i.c.v.-administration ouabain, a selective inhibitor of the Na + pump, and by endothelin (ET-1), an endogenous peptide that is present in the CNS, suggesting that this peptide may participate in the neural regulation of arterial pressure via modulation of Na + -pump activity