C. Cogliati et al., Detection of low- and high-frequency rhythms in the variability of skin sympathetic nerve activity, AM J P-HEAR, 278(4), 2000, pp. H1256-H1260
Citations number
25
Categorie Soggetti
Cardiovascular & Hematology Research
Journal title
AMERICAN JOURNAL OF PHYSIOLOGY-HEART AND CIRCULATORY PHYSIOLOGY
Spectral analysis of skin blood flow has demonstrated low-frequency (LF, 0.
03-0.15 Hz) and high-frequency (HF, 0.15-0.40 Hz) oscillations, similar to
oscillations in R-R interval, systolic pressure, and muscle sympathetic ner
ve activity (MSNA). It is not known whether the oscillatory profile of skin
blood flow is secondary to oscillations in arterial pressure or to oscilla
tions in skin sympathetic nerve activity (SSNA). MSNA and SSNA differ marke
dly with regard to control mechanisms and morphology. MSNA contains vasocon
strictor fibers directed to muscle vasculature, closely regulated by barore
ceptors. SSNA contains both vasomotor and sudomotor fibers, differentially
responding to arousals and thermal stimuli. Nevertheless, MSNA and SSNA sha
re certain common characteristics. We tested the hypothesis that LF and HF
oscillatory components are evident in SSNA, similar to the oscillatory comp
onents present in MSNA. We studied 18 healthy normal subjects and obtained
sequential measurements of MSNA and SSNA from the peroneal nerve during sup
ine rest. Measurements were also obtained of the electrocardiogram, beat-by
-beat blood pressure (Finapres), and respiration. Spectral analysis showed
LF and I-IF oscillations in MSNA, coherent with similar oscillations in bot
h R-R interval and systolic pressure. The HF oscillation of MSNA was cohere
nt with respiration. Similarly, LF and HF spectral components were evident
in SSNA variability, coherent with corresponding variability components of
R-R interval and systolic pressure. HF oscillations of SSNA were coherent w
ith respiration. Thus our data suggest that these oscillations may be funda
mental characteristics shared by MSNA and SSNA, possibly reflecting common
central mechanisms regulating sympathetic outflows subserving different reg
ions and functions.