Regulation of Na+-K+ pump activity in erythrocytes and blood pressure in anephric rats.
This study was designed to explore factors involved in the regulation of Na-K pumps in erythrocytes and blood pressure in anephric Sprague-Dawley female rats. Twenty-four hours following bilateral nephrectomy, the rats were given a 1-h infusion of 1 ml of either 0.9% or 5.4% saline, or 5% or 30% glucose. At the completion of the infusion, tail blood pressure was determined and blood was drawn for the measurement of the ouabain-furosemide-sensitive sodium efflux rate constant in erythrocytes. Infusion of 5.4% saline or 30% glucose caused a significant reduction in the erythrocyte sodium efflux rate constant, more pronounced with the former, and an elevation in blood pressure. Nephrectomy or infusion of 0.9% saline or 5% glucose had no effect on either parameter. These findings suggest that in anephric rats (1) extracellular fluid hyperosmolality rather than extracellular fluid volume expansion inhibits the Na-K pump in all cells; (2) a Na-K pump inhibitor is involved in the genesis of hypertension.
Birbari
A E
AE
Division of Nephrology-Hypertension, American University Medical Center, Beirut, Lebanon.
Hajj-Ali
A F
AF
Mukaddam-Daher
S S
SS
Jirjus
A R
AR
D000818:Animals; D004912:Erythrocytes / Q000378:metabolism; D005260:Female; D005665:Furosemide / Q000494:pharmacology; D006977:Hypertension, Renal / Q000378:metabolism*; D009392:Nephrectomy; D010042:Ouabain / Q000494:pharmacology; D051381:Rats; D012964:Sodium / Q000378:metabolism*; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors / Q000378:metabolism*
D010042:Ouabain; D005665:Furosemide; D012964:Sodium; D000254:Sodium-Potassium-Exchanging ATPase