Hyperoxia caused by microdialysis perfusion decreased striatal monoamines: involvement of oxidative stress.
Due to complex influence, such as utilization and permeability of arterial vessels to oxygen, there is a considerable difference of oxygen tension between extracellular fluid and perfusate usually used in microdialysis (30-60 Torr versus 145 Torr). Dialysate dopamine and monoamine metabolites-3,4-dihydroxyphenylacetic acid, homovanillic acid and 5-hydroxyindoleacetic acid were measured under different kinds of oxygen tension solutions (145, 72, 48 Torr). In the acute and anesthetized group, dopamine, 3,4-dihydroxyphenylacetic acid, 5-hydroxyindoleacetic acid and homovanillic acid increased 72, 93, 86 and 65%, respectively when changing the perfusate from 145 Torr to near physiological 48 Torr, while in chronic and conscious group, carried out 72 h after surgery, these compounds showed obscure increases (only homovanillic acid produced a significant change of 14%). The different effect of perfusate oxygen tension on dialysate levels of monoamines in anesthetized and conscious rats might be caused by oxidative stress triggered by hyperoxia combined with anesthesia and surgical trauma.
Wang
Lei
L
Center for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080, PR China.
Osborne
Peter G
PG
Yu
Xiao
X
Shangguan
DiHua
D
Zhao
Rui
R
Han
HuiWan
H
Liu
GuoQuan
G
D000818:Animals; D015306:Biogenic Monoamines / Q000378:metabolism*; D003342:Corpus Striatum / Q000378:metabolism*; D018496:Hyperoxia / Q000209:etiology*; D008297:Male; D017551:Microdialysis; D018384:Oxidative Stress; D051381:Rats; D017208:Rats, Wistar
D015306:Biogenic Monoamines