Red blood cell Li+-Na+ countertransport, Na+-K+ cotransport, and the hemodynamics of hypertension.
Red blood cell Li+-Na+ countertransport and Na+-K+ cotransport activities, home blood pressure, invasive systemic hemodynamics, and limb venous compliance were measured in 65 white men (23 normotensive, 22 borderline hypertensive, and 20 mild essential hypertensive subjects). Li+-Na+ countertransport activity was positively and significantly correlated with subject-determined home systolic blood pressure (r = 0.31, p less than 0.02) and with directly measured systolic (r = 0.29, p less than 0.02) and diastolic (r = 0.27, p less than 0.03) blood pressures in the hemodynamic laboratory, independent of potential confounding variables. Analysis of the hemodynamic determinants of blood pressure revealed a significant positive correlation of countertransport with vascular resistance (r = 0.30, p less than 0.02) but not with cardiac output or cardiac index. High red blood cell Na+-K+ cotransport activity was not independently associated with hypertension or with a characteristic hemodynamic pattern but was related to decreased venous compliance. Red blood cell Li+-Na+ countertransport deserves further study as a marker for the genetic substrate of human essential hypertension. Red cell Na+-K+ cotransport may be altered secondarily by factors related to high blood pressure and seems to be a valid marker for abnormalities of the venous system in hypertension.
D000328:Adult; D017920:Antiporters; D001794:Blood Pressure; D002352:Carrier Proteins / Q000097:blood*; D004912:Erythrocytes / Q000378:metabolism*; D006439:Hemodynamics; D006801:Humans; D006973:Hypertension / Q000097:blood / Q000503:physiopathology*; D008094:Lithium / Q000097:blood; D008875:Middle Aged; D011188:Potassium / Q000097:blood; D012964:Sodium / Q000097:blood; D028021:Sodium-Potassium-Chloride Symporters; D014655:Vascular Resistance
D017920:Antiporters; D002352:Carrier Proteins; D028021:Sodium-Potassium-Chloride Symporters; C045885:sodium-lithium countertransporter; D008094:Lithium; D012964:Sodium; D011188:Potassium