TY - JOUR
T1 - Increased vasomotor sympathetic nerve activity and decreased plasma nitric oxide release after head-down bed rest in humans
T2 - Disappearance of correlation between vasoconstrictor and vasodilator
AU - Kamiya, Atsunori
AU - Iwase, Satoshi
AU - Michikami, Daisaku
AU - Fu, Qi
AU - Mano, Tadaaki
AU - Kitaichi, Kiyoyuki
AU - Takagi, Kenji
PY - 2000/3/3
Y1 - 2000/3/3
N2 - We hypothesized that the relationship between resting levels of sympathetic vasoconstrictor nerve traffic and dilator substance nitric oxide (NO) release is altered after exposure to microgravity, resulting in abnormal peripheral resistance. To examine the hypothesis, we assessed muscle sympathetic nerve activity (MSNA) (microneurography), an indicator of NO release (plasma nitrite/nitrate concentrations) and leg vascular resistance (venous occlusion plethysmography) in 20 healthy male volunteers before and after 14 days of 6°head-down bed rest (HDBR), the ground-based analogue of microgravity. MSNA increased, while plasma nitrite/nitrate concentrations decreased after HDBR. A significant positive correlation observed between MSNA and plasma nitrite/nitrate concentrations before HDBR disappeared after HDBR. Leg vascular resistance increased after HDBR. In conclusion, an imbalance between sympathetic vasoconstrictor traffic and NO release might contribute to elevated peripheral vascular resistance following HDBR. (C) 2000 Elsevier Science Ireland Ltd.
AB - We hypothesized that the relationship between resting levels of sympathetic vasoconstrictor nerve traffic and dilator substance nitric oxide (NO) release is altered after exposure to microgravity, resulting in abnormal peripheral resistance. To examine the hypothesis, we assessed muscle sympathetic nerve activity (MSNA) (microneurography), an indicator of NO release (plasma nitrite/nitrate concentrations) and leg vascular resistance (venous occlusion plethysmography) in 20 healthy male volunteers before and after 14 days of 6°head-down bed rest (HDBR), the ground-based analogue of microgravity. MSNA increased, while plasma nitrite/nitrate concentrations decreased after HDBR. A significant positive correlation observed between MSNA and plasma nitrite/nitrate concentrations before HDBR disappeared after HDBR. Leg vascular resistance increased after HDBR. In conclusion, an imbalance between sympathetic vasoconstrictor traffic and NO release might contribute to elevated peripheral vascular resistance following HDBR. (C) 2000 Elsevier Science Ireland Ltd.
KW - Bed rest
KW - Microneurography
KW - Muscle sympathetic nerve activity
KW - Vascular resistance
KW - Vasoconstrictor
KW - Vasodilator
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U2 - 10.1016/S0304-3940(00)00804-1
DO - 10.1016/S0304-3940(00)00804-1
M3 - Article
C2 - 10686406
AN - SCOPUS:0033957054
VL - 281
SP - 21
EP - 24
JO - Neuroscience Letters
JF - Neuroscience Letters
SN - 0304-3940
IS - 1
ER -