Racial differences in epinephrine and beta 2-adrenergic receptors.
This study examined the effects of ethnicity and hypertension on beta 2-adrenergic receptors and on plasma catecholamines in a group of 77 unmedicated mildly hypertensive and normotensive men. Black hypertensive subjects had the most sensitive and white hypertensive subjects the least sensitive beta-receptors (as assessed by isoproterenol-stimulated cyclic AMP in lymphocytes [P = .02]). In contrast, postreceptor adenylate cyclase activation (as assessed by forskolin stimulation) was similar among groups. As with beta-receptor sensitivity, black hypertensive subjects had the highest beta-receptor density and white hypertensive subjects the lowest (P = .03). Blacks demonstrated lower plasma epinephrine values compared with whites (P = .03). Across all subjects, plasma epinephrine was negatively correlated with beta-receptor density (r = -.26, P < .05) and sensitivity (r = -.25, P < .05). There were no group differences in binding affinity to the beta-antagonist iodopindolol. The findings support the notion of increased beta-adrenergic receptors in hypertension in blacks.
Mills
P J
PJ
University of California at San Diego Medical Center 92103-0804.
Dimsdale
J E
JE
Ziegler
M G
MG
Nelesen
R A
RA
D000328:Adult; D044383:Black People; D000242:Cyclic AMP / Q000096:biosynthesis; D004837:Epinephrine / Q000097:blood*; D006801:Humans; D006973:Hypertension / Q000097:blood / Q000208:ethnology* / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009638:Norepinephrine / Q000097:blood; D018343:Receptors, Adrenergic, beta-2 / Q000032:analysis* / Q000502:physiology; D012964:Sodium / Q000652:urine; D044465:White People
D018343:Receptors, Adrenergic, beta-2; D012964:Sodium; D000242:Cyclic AMP; D009638:Norepinephrine; D004837:Epinephrine