Antihypertensive compounds that modulate the Na-K pump.

Area of Science:

• Nephrology
• Cardiology
• Pharmacology

Background:

• Hypertension is linked to impaired kidney sodium excretion, associated with adducin mutations or increased endogenous ouabain (EO).
• Endogenous ouabain (EO) and mutated adducin activate renal Na/K-ATPase, contributing to hypertension and potential cardiac complications.

Purpose of the Study:

• To develop and evaluate a novel antihypertensive agent, PST 2238, targeting specific alterations in renal Na/K-ATPase function.
• To assess PST 2238's efficacy in normalizing blood pressure and preventing cardiovascular complications in hypertensive models.

Main Methods:

• PST 2238 was administered orally to genetic rat models (MHS, OS) and tested in cultured renal cells (NRK) with mutated adducin or EO.
• Effects on blood pressure, renal Na-K pump expression/activity, and cardiac/kidney weights were measured.
• Gene expression related to OU-dependent growth pathways was analyzed.

Main Results:

• PST 2238 lowered blood pressure in MHS and OS rats at low oral doses (0.1-10 micro g/kg).
• PST 2238 normalized Na-K pump activity in cultured cells and in vivo.
• PST 2238 prevented left ventricle and kidney hypertrophy in OS rats by antagonizing EO-induced gene activation.

Conclusions:

• PST 2238 is a novel antihypertensive agent with selective action on the renal Na-K pump.
• PST 2238 demonstrates potential in preventing hypertension-associated cardiovascular complications.
• The drug's mechanism involves modulating Na-K pump function and inhibiting OU-dependent growth pathways.