Alteration in the Sarcolemmal Na⁺-K⁺ Pump of Hindquarters Resistance Arteries in Doca-Salt Rats

Abstract

It has been suggested that a circulating inhibitor of the Na⁺-K⁺ pump contributes to the development and maintenance of DOCA-salt hypertension. However, the discordant results have been reported as to whether the sarcolemmai Na⁺-K⁺ pump in DOCA-salt hypertension is inhibited. Furthermore, no study has examined alteration in the sarcolemmal Na⁺-K⁺ pump of the true resistance arteries. We examined hindquarters vasoconstriction induced by ouabain (10⁻³ M) in the vascularly isolated hindquarters of the DOCA-salt treated or control rats, which were perfused with Krebs-Henseleit solution. Hindquarters vasoconstriction induced by ouabain (10⁻³ M) was greater in the prehypertensive and hypertensive DOCA-salt rats than in the corresponding control rats (p > 0.01). We also examined hindquarters vasoconstriction induced by ouabain (10⁻³ M) in the vascularly isolated hindquarters of the normal assay rats which

Key Words:

• Na⁺-K⁺ pump
• circulating pump inhibitor
• ouabain
• DOCA-salt hypertension