[Effects of rotating-table simulated "push-pull maneuver" on cerebral circulation function].
OBJECTIVE
To investigate the change and regulation of cerebral circulation during rotating-table simulated push-pull maneuver.


METHODS
A special rotating-table was used to simulate the push-pull maneuver. 10 healthy adults were subjected to a series of "head-up stand (+1Gz) 1 min head-down stand (-1Gz) 10 s and head-up stand (+1Gz) 1 min" changes. Cerebral blood flow velocity and pulsatility indices in the left middle cerebral artery were constantly measured with a TC2020TCD using Transcranial Doppler [correction of Transcanial Dopplor] instrument.


RESULTS
During 10 s head-down stand (-1Gz) systolic velocity (Vs) increased, diastolic velocity (Vd) decreased, and the pulsatility indices (PI and RI) increased significantly in the left middle cerebral artery. During subsequent head-up stand (+1Gz), these changes didn't resume immediately and maintained for at least 20 s.


CONCLUSIONS
This result implied that the push-pull maneuver increased the resistance of the cerebral vessels, which might be one of the mechanisms of the push-pull effect.
Zhang
W X
WX
Institute of Aviation Medicine, Air Force, Beijing, China.
Zhan
C L
CL
Geng
X C
XC
Yan
G D
GD
Lu
X
X
Chu
X
X
D000328:Adult; D001783:Blood Flow Velocity; D002536:Cerebral Arteries / Q000502:physiology; D002560:Cerebrovascular Circulation / Q000502:physiology*; D006112:Gravitation; D006801:Humans; D020768:Middle Cerebral Artery / Q000502:physiology*; D011187:Posture / Q000502:physiology*; D012039:Regional Blood Flow; D012399:Rotation; D018667:Tilt-Table Test