Muscle sympathetic nervous system activity in black and Caucasian hypertensive subjects.
OBJECTIVE
To compare muscle sympathetic nerve activity (MSNA) in age- and weight-matched African-Americans and American Caucasians with primary hypertension.


METHODS
Using microneurography, we compared MSNA at rest and in response to cold-pressor testing and handgrip exercise in 13 hypertensive African-Americans and 12 hypertensive American Caucasians.


METHODS
All subjects were withdrawn from antihypertensive medications for at least 2 weeks before the study. MSNA was recorded from the left peroneal nerve.


RESULTS
Resting MSNA was similar in the Blacks and the Caucasians. Increases in muscle efferent activity, mean arterial pressure and heart rate in response to the cold pressure and handgrip exercise were not significantly different in Black and in Caucasian subjects.


CONCLUSIONS
MSNA, either at rest or in response to certain laboratory stressors, is not different in Black and in Caucasian hypertensive subjects with similar resting blood pressures.
Calhoun
D A
DA
Division of Cardiovascular Disease, University of Alabama at Birmingham 35294.
Mutinga
M L
ML
Wyss
J M
JM
Oparil
S
S
D000367:Age Factors; D044383:Black People; D001835:Body Weight; D003080:Cold Temperature; D015444:Exercise; D005260:Female; D006439:Hemodynamics; D006801:Humans; D006973:Hypertension / Q000208:ethnology* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000294:innervation* / Q000502:physiology; D011188:Potassium / Q000652:urine; D012964:Sodium / Q000652:urine; D013564:Sympathetic Nervous System / Q000502:physiology*; D044465:White People; D001741:Black or African American
D012964:Sodium; D011188:Potassium