title: Mineralocorticoid exposure and receptor activity modulate microvascular endothelial function in African Americans with and without hypertension.
abstract: Prior work suggests blood pressure in African Americans is more sensitive to the effects of aldosterone than in Caucasians. This mechanism may relate to a negative response of the vascular endothelium to aldosterone, including reduced glucose-6-phosphate dehydrogenase (G6PD) activity. Thirty-three African Americans (11 hypertensives, 22 controls) without evidence of diabetes or metabolic syndrome completed the protocol. The protocol included measurement of in vivo microvascular endothelial function by digital pulse arterial tonometry and ex vivo measurement of endothelial function by videomicroscopy of arterioles obtained from these same subjects with and without exposure to aldosterone or spironolactone. Systemic and arteriolar G6PD activities were also measured. In vivo and ex vivo microvascular endothelial function were impaired in African Americans with hypertension. One-hour exposure with aldosterone impaired endothelium-dependent vasodilation in arterioles from normotensive subjects, while 1 hour of spironolactone exposure reversed endothelial dysfunction in arterioles from hypertensive subjects. G6PD activity was impaired in hypertensive arterioles. Aldosterone-related endothelial dysfunction may be responsible for at least a portion of the greater blood pressure sensitivity to aldosterone in African Americans. This may be in part related to vascular suppression of G6PD activity.
authors.affiliation: Department of Medicine, Medical College of Wisconsin, Milwaukee, WI, USA.
authors.forename: Appesh
authors.initials: A
authors.lastname: Mohandas
authors.affiliation: Department of Medicine, Division of Cardiovascular Medicine, Medical College of Wisconsin, Milwaukee, WI, USA.
authors.forename: Tisha B
authors.initials: TB
authors.lastname: Suboc
authors.affiliation: Department of Medicine, Division of Cardiovascular Medicine, Medical College of Wisconsin, Milwaukee, WI, USA.
authors.forename: Jingli
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Medicine, Division of Cardiovascular Medicine, Medical College of Wisconsin, Milwaukee, WI, USA.
authors.forename: Rong
authors.initials: R
authors.lastname: Ying
authors.affiliation: Department of Biostatistics, Medical College of Wisconsin, Milwaukee, WI, USA.
authors.forename: Sergey
authors.initials: S
authors.lastname: Tarima
authors.affiliation: Department of Medicine, Division of Cardiovascular Medicine, Medical College of Wisconsin, Milwaukee, WI, USA.
authors.forename: Kodlipet
authors.initials: K
authors.lastname: Dharmashankar
authors.affiliation: Department of Medicine, Division of Cardiovascular Medicine, Medical College of Wisconsin, Milwaukee, WI, USA.
authors.forename: Mobin
authors.initials: M
authors.lastname: Malik
authors.affiliation: Department of Medicine, Division of Cardiovascular Medicine, Medical College of Wisconsin, Milwaukee, WI, USA mwidlans@mcw.edu.
authors.forename: Michael E
authors.initials: ME
authors.lastname: Widlansky
mesh_terms: D000328:Adult; D001741:Black or African American; D000450:Aldosterone; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology; D004730:Endothelium, Vascular / Q000187:drug effects* / Q000378:metabolism; D005260:Female; D006801:Humans; D006973:Hypertension / Q000503:physiopathology*; D008297:Male; D000451:Mineralocorticoid Receptor Antagonists / Q000494:pharmacology*; D008901:Mineralocorticoids / Q000378:metabolism*; D013148:Spironolactone / Q000378:metabolism*; D014664:Vasodilation / Q000187:drug effects*
chemical_list: D000451:Mineralocorticoid Receptor Antagonists; D008901:Mineralocorticoids; D013148:Spironolactone; D000450:Aldosterone
keywords: African American; aldosterone; endothelial function; hypertension; microvasculature