[The damage effects of hypothermia combined with hypoxia on rat pulmonary microvascular endothelial cells].
OBJECTIVE
To study the synergistic effects of hypothermia and hypoxia on the damage of pulmonary microvascular endothelial cells (PMVEC) in rat.


METHODS
Primary PMVECs were obtained by complex phosphoesterasum digesting from isolated lung tissues of Wistar rats, the PMVECs were identified by phase contrast microscope and immunofluorescence studies for CD31 antigen and bandeiraea simplicifolia isolectin (BSI) binding test. Factorial design was adopted in trial according to hypothermia and hypoxia existing or not. Using corresponding kit measured the levels of lactate dehydrogenase (LDH) activity in cell medium. Level of nitric oxide (NO) concentration was measured by Griess Assay. RT-PCR was used to examine the expression of vascular endothelial growth factor (VEGF), endothelin-1 (ET-1) mRNA in PMVECs.


RESULTS
The monolayer of cultured PMVECs displayed the shape of pavingstone. CD31 antigen and binding BSI results by fluorescence microscope identified the cultured cells were PMVECs. Compared to the control group, LDH activity and VEGF, ET-1 expression levels were significantly increased in hypothermia group, hypoxia group and hypoxia combined with hypothermia group. And the levels of NO concentration were reduced in these three groups. The results of One-way ANOVA showed that there was a synergistic effect between hypothermia and hypoxia.


CONCLUSIONS
Hypothermia and hypoxia both have an effect on PMVECs whether in altering the cell permeability or in releasing of vasoactive substances including NO and ET-1. In addition, there is a synergistic effect between hypothermia and hypoxia.
School of Public Health, Central South University, Changsha 410078, China.
Jing-Dan
JD
Zhang
Dan-Feng
DF
Yang
Yan-Qing
YQ
Cao
Xi
X
Li
Yu-Lin
YL
An
Jia-Ying
JY
Liu
Hai
H
Wang
D000818:Animals; D015687:Cell Hypoxia; D002463:Cell Membrane Permeability; D002478:Cells, Cultured; D003080:Cold Temperature; D042783:Endothelial Cells / Q000166:cytology* / Q000378:metabolism; D019332:Endothelin-1 / Q000378:metabolism; D004730:Endothelium, Vascular / Q000166:cytology; D008168:Lung / Q000098:blood supply; D008297:Male; D009569:Nitric Oxide / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D017208:Rats, Wistar; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism
D019332:Endothelin-1; D012333:RNA, Messenger; D042461:Vascular Endothelial Growth Factor A; C467498:vascular endothelial growth factor A, rat; D009569:Nitric Oxide