[Early cardiac myocyte membrane changes in severely burned rats: a spin labding-ESR study].
OBJECTIVE
To demonstrate the mechanism of early cardiac myocyte membrane damage at molecular level in severely burned rats.


METHODS
SD rats were randomly divided into sham-burn and burn groups. A 30% TBSA burn was created in burn group. Hearts were obtained at different time postburn. Cardiac myocytes isolated by collagenase using Langendoff perfusion apparatus were spin labeled with 5-doxylstearic acid (5NS), 16-doxylstearic acid (16NS) and 3-maleidoproxyl (3MP). The order parameters (S value), hs/hw ratio and rotational correlation time (tau c) were measured according to the spin labeling-ESR spectra.


RESULTS
The S value of the polar head-group region of membrane lipid, as reported by 5NS, did not changed significantly, while that of the lipid in the hydrophobic midzone, as reported by 16NS, increased significantly. The hs/hw ratio of 2 and 6 hours postburn groups increased significantly postburn compared with that of the sham-burn group, and so did the rotational correlation time in 1 to 12 h postburn groups.


CONCLUSIONS
There were structural and functional changes in cardiac myocyte membrane after burn injury. They were characterized by decreased fluidity in the deeper part of membrane lipid, configurational changes and motion restriction in membrane proteins. They could affect the normal performance of cardiac function.
Tang
H
H
Department of Burns, Changhai Hospital, Second Military Medical University, Shanghai, 200433.
Chen
Y
Y
Shen
H
H
D000818:Animals; D002056:Burns / Q000473:pathology*; D002462:Cell Membrane / Q000473:pathology; D004578:Electron Spin Resonance Spectroscopy; D005260:Female; D008297:Male; D009206:Myocardium / Q000473:pathology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013113:Spin Labels
D013113:Spin Labels