Neurohumoral Factors Involved in the Pathogenesis of Hypertension

Abstract

The sodium, potassium activated adenosine triphosphatase (Na⁺, K⁺-ATPase) is present in most animal cells. This membrane-embedded enzyme is responsible for the active transport of sodium and potassium across the plasma membrane. The resulting concentration gradients largely determine resting membrane potential and participate in cell volume homeostasis. The cardiac glycoside ouabain and its derivatives such as strophantidin can specifically inhibit the Na⁺, K⁺-ATPase allowing the sodium and potassium gradients to dissipate. The existence of a specific binding site for these plant alkaloids raises the possibility of the existence of an unknown digitalis-like compound which would regulate the activity of the enzyme through this binding site.