Inhibition of guinea-pig renal [Na + K]-ATPase by normotensive human plasma: effects of a high sodium diet.
The effect of plasma taken from normotensive humans, while on a low and high sodium diet, on [Na + K]-ATPase and 3H-ouabain binding was measured in tubules from guinea-pig kidneys. Plasma from the high sodium, compared to the low sodium, diet period: (a) inhibited [Na + K]-ATPase activity; (b) decreased 3H-ouabain affinity for binding sites; (c) increased the number of available 3H-ouabain binding sites; (d) decreased [Na + K]-ATPase turnover (activity/3H-ouabain binding sites). The inhibition of [Na + K]-ATPase suggests an increase in a (possible) natriuretic factor. The decreased affinity of 3H-ouabain binding suggests an endogenous ouabainoid, which may be the natriuretic factor.
D000328:Adult; D000818:Animals; D001665:Binding Sites; D004039:Diet, Sodium-Restricted; D005260:Female; D006168:Guinea Pigs; D006801:Humans; D007684:Kidney Tubules / Q000201:enzymology*; D008297:Male; D008875:Middle Aged; D010042:Ouabain / Q000378:metabolism; D010949:Plasma / Q000502:physiology*; D012964:Sodium / Q000378:metabolism; D012965:Sodium Chloride / Q000494:pharmacology*; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors*
D012965:Sodium Chloride; D010042:Ouabain; D012964:Sodium; D000254:Sodium-Potassium-Exchanging ATPase