Increased sodium-lithium countertransport in black non-insulin-dependent diabetic hypertensives.
Black hypertensive diabetics have been shown to exhibit elevated intracellular calcium which may stimulate Na/H antiport. Since Na/Li countertransport appears to be a functional mode of Na/H antiport, we measured erythrocyte Na/Li countertransport in nondiabetic normotensive and hypertensive blacks and whites and hypertensive non-insulin-dependent diabetic blacks. Na/Li countertransport was significantly lower in the blacks than in the whites (0.170 +/- 0.017 v 0.230 +/- 0.017 mmol/L/h, P less than .02), but there was no significant difference between the black hypertensives and normotensives. In contrast, black hypertensive diabetics exhibited a significant increase in Na/Li countertransport compared to normotensive and hypertensive nondiabetic blacks (0.252 +/- 0.032 v 0.170 +/- 0.017, P less than .02. Thus, these data indicate that the activity of this antiporter is elevated in black diabetics, possibly further contributing to the development of hypertension in this population.
Johnson
B A
BA
Department of Nutrition and Food Science, Wayne State University, Detroit, Michigan 48202.
Sowers
J R
JR
Zemel
P C
PC
Luft
F C
FC
Zemel
M B
MB
D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D017920:Antiporters; D001692:Biological Transport / Q000502:physiology; D044383:Black People; D002352:Carrier Proteins / Q000378:metabolism; D003925:Diabetic Angiopathies / Q000097:blood* / Q000150:complications / Q000235:genetics; D004912:Erythrocytes / Q000032:analysis*; D005069:Evaluation Studies as Topic; D005260:Female; D006801:Humans; D006973:Hypertension / Q000097:blood / Q000150:complications / Q000235:genetics / Q000378:metabolism*; D008094:Lithium / Q000097:blood / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D012964:Sodium / Q000097:blood / Q000378:metabolism*; D044465:White People
D017920:Antiporters; D002352:Carrier Proteins; D008094:Lithium; D012964:Sodium