title: Circulating digitalis-like compounds in essential hypertension.
abstract: Inhibitors of the Na+ pump have been proposed as participating in sodium excretion, extracellular fluid regulation, and in the rise of blood pressure. The presence of digitalis-like compounds in human plasma has been investigated by comparing the effects of plasma extracts to those of ouabain in 4 tests. - competition with ouabain for binding to the Na+ pump, - inhibition of Na+ and K+ dependent hydrolysis - inhibition of serotonin uptake by human platelets - central hypertensive effect Plasma fractions exhibited digitalis-like properties in the 4 tests. The effects of plasma extracts of 42 normotensive subjects (21 with family history of hypertension) and 38 patients with essential hypertension (15 with antihypertensive treatment) and 9 patients with chronic renal failure were compared. Plasma from Forty per cent of untreated hypertensive patients and normotensives with hypertensive heredity had a high inhibition level. Inhibition was enhanced in beta-blocker treated patients and decreased in those on diuretics. No digitalis-like activity was observed in uremic plasma. These observations strongly suggest the presence of digitalis-like compound(s) in human plasma and point to its possible association with hypertension.
mesh_terms: D000328:Adult; D000368:Aged; D000818:Animals; D001792:Blood Platelets / Q000378:metabolism; D002319:Cardiovascular System / Q000187:drug effects; D004071:Digitalis Glycosides / Q000097:blood*; D004912:Erythrocytes / Q000378:metabolism; D005260:Female; D006801:Humans; D006973:Hypertension / Q000097:blood*; D008297:Male; D008875:Middle Aged; D010042:Ouabain / Q000097:blood / Q000494:pharmacology; D051381:Rats; D012701:Serotonin / Q000097:blood; D012964:Sodium / Q000097:blood; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors / Q000097:blood
chemical_list: D004071:Digitalis Glycosides; D012701:Serotonin; D010042:Ouabain; D012964:Sodium; D000254:Sodium-Potassium-Exchanging ATPase