TY - JOUR
T1 - Comparison between reproducibility and sensitivity of muscle sympathetic nerve traffic and plasma noradrenaline in man
AU - Grassi, Guido
AU - Bolla, Giambattista
AU - Seravalle, Gino
AU - Turri, Carlo
AU - Lanfranchi, Antonio
AU - Mancia, Giuseppe
PY - 1997
Y1 - 1997
N2 - 1. Although plasma noradrenaline and muscle sympathetic nerve traffic have been shown to be suitable markers of sympathetic activity in man, no study has systematically compared the reproducibility and sensitivity of these two indices of adrenergic tone. 2. Reproducibility data were collected in 10 subjects, in whom plasma noradrenaline was assessed by HPLC on blood samples withdrawn from an antecubital vein and efferent postganglionic muscle sympathetic nerve activity was measured by microneurography from a peroneal nerve, together with arterial blood pressure (Finapres technique). Measurements were obtained in a first session (session 1), 60 min later (session 2) and after 14 days (session 3). While muscle sympathetic nerve activity values recorded in the three different experimental sessions were closely and significantly correlated with each other (r always > 0.90, P <0.001), noradrenaline showed a less significant correlation between sessions 1 and 2 (r = 0.71, P <0.05) or no correlation between sessions 1 and 3 (r = 0.45, P not significant). 3. Sensitivity data were collected by evaluating muscle sympathetic nerve activity and noradrenaline values in three different age groups (young, middle-age and old subjects, n = 18), in three groups with different blood pressures (normotensive, mild and severe hypertensive subjects, n = 30) and in a group of eight subjects before and after a physical training programme, i.e. conditions known to increase or reduce sympathetic cardiovascular drive. Muscle sympathetic nerve activity was significantly increased by aging and hypertension, and reduced by physical training. The noradrenaline changes were much less marked and consistent. 4. These data suggest that muscle sympathetic nerve activity has a greater short- and medium-term reproducibility than noradrenaline. In several conditions known to modify sympathetic cardiovascular drive muscle sympathetic nerve activity also appears to change more clearly than noradrenaline.
AB - 1. Although plasma noradrenaline and muscle sympathetic nerve traffic have been shown to be suitable markers of sympathetic activity in man, no study has systematically compared the reproducibility and sensitivity of these two indices of adrenergic tone. 2. Reproducibility data were collected in 10 subjects, in whom plasma noradrenaline was assessed by HPLC on blood samples withdrawn from an antecubital vein and efferent postganglionic muscle sympathetic nerve activity was measured by microneurography from a peroneal nerve, together with arterial blood pressure (Finapres technique). Measurements were obtained in a first session (session 1), 60 min later (session 2) and after 14 days (session 3). While muscle sympathetic nerve activity values recorded in the three different experimental sessions were closely and significantly correlated with each other (r always > 0.90, P <0.001), noradrenaline showed a less significant correlation between sessions 1 and 2 (r = 0.71, P <0.05) or no correlation between sessions 1 and 3 (r = 0.45, P not significant). 3. Sensitivity data were collected by evaluating muscle sympathetic nerve activity and noradrenaline values in three different age groups (young, middle-age and old subjects, n = 18), in three groups with different blood pressures (normotensive, mild and severe hypertensive subjects, n = 30) and in a group of eight subjects before and after a physical training programme, i.e. conditions known to increase or reduce sympathetic cardiovascular drive. Muscle sympathetic nerve activity was significantly increased by aging and hypertension, and reduced by physical training. The noradrenaline changes were much less marked and consistent. 4. These data suggest that muscle sympathetic nerve activity has a greater short- and medium-term reproducibility than noradrenaline. In several conditions known to modify sympathetic cardiovascular drive muscle sympathetic nerve activity also appears to change more clearly than noradrenaline.
KW - Aging
KW - Hypertension
KW - Noradrenaline
KW - Physical training
KW - Sympathetic activity
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M3 - Article
C2 - 9093009
AN - SCOPUS:0030888977
VL - 92
SP - 285
EP - 289
JO - Clinical Science
JF - Clinical Science
SN - 0143-5221
IS - 3
ER -