Impaired antioxidant defence in guinea pig heart tissues treated with halothane.
OBJECTIVE
To investigate the effects of halothane and halothane plus vitamin E treatment on myocardial free radical metabolism in guinea pigs.


METHODS
Four groups of seven animals were studied: control, halothane, halothane plus vitamin E and vitamin E groups. In the halothane group, halothane 1.5% in oxygen was given for 90 min over three days. In the halothane plus vitamin E group, 300 mg.kg-1.day-1 vitamin E im was started three days before the first halothane treatment and continued for three days. Following sacrifice, the hearts were assayed for superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT) and malondialdehyde (MDA) level was determined. Electron spin resonance (ESR) analysis and electron microscopy (EM) were also performed.


RESULTS
In the halothane group, SOD activities and MDA concentrations were increased compared with control and GSH-Px and CAT activities were decreased. In the halothane plus vitamin E group, there were no differences in enzyme activity compared with halothane alone but the MDA level was decreased. In the vitamin E group, enzyme activities were increased compared with control. Mainly the CF3CHCl radical was identified by ESR analysis in heart tissues exposed to halothane and the concentration of this radical was reduced by vitamin E. Electron microscopy showed cytoplasmic vacuolisation and dilation in sarcoplasmic reticulum in the heart tissues exposed to halothane: both were prevented by vitamin E.


CONCLUSIONS
Although halothane causes impairment in enzymatic antioxidant defence potential, due to lowered GSH-Px and CAT activity, and accelerates peroxidative reactions in the tissues affected, no subcellular damage occurred. Vitamin E may protect tissues against free radical attack by scavenging toxic free radicals formed in heart tissue during halothane anaesthesia.
Durak
I
I
Department of Biochemistry, Ankara University Medical Faculty, Turkey.
Kurtipek
O
O
Oztürk
H S
HS
Birey
M
M
Güven
T
T
Kavutcu
M
M
Kaçmaz
M
M
Dikmen
B
B
Yel
M
M
Canbolat
O
O
D018685:Anesthetics, Inhalation / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D001219:Aspartate Aminotransferases / Q000097:blood / Q000187:drug effects; D002374:Catalase / Q000187:drug effects / Q000378:metabolism; D003593:Cytoplasm / Q000187:drug effects / Q000648:ultrastructure; D004578:Electron Spin Resonance Spectroscopy; D016166:Free Radical Scavengers / Q000008:administration & dosage / Q000494:pharmacology; D005609:Free Radicals / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000187:drug effects / Q000378:metabolism; D006168:Guinea Pigs; D006221:Halothane / Q000008:administration & dosage / Q000494:pharmacology*; D007273:Injections, Intramuscular; D007770:L-Lactate Dehydrogenase / Q000097:blood / Q000187:drug effects; D008315:Malondialdehyde / Q000378:metabolism; D008854:Microscopy, Electron; D009206:Myocardium / Q000201:enzymology / Q000378:metabolism* / Q000648:ultrastructure; D016877:Oxidants / Q000378:metabolism; D012519:Sarcoplasmic Reticulum / Q000187:drug effects / Q000648:ultrastructure; D013482:Superoxide Dismutase / Q000187:drug effects / Q000378:metabolism; D013997:Time Factors; D014617:Vacuoles / Q000187:drug effects / Q000648:ultrastructure; D014810:Vitamin E / Q000008:administration & dosage / Q000494:pharmacology
D018685:Anesthetics, Inhalation; D000975:Antioxidants; D016166:Free Radical Scavengers; D005609:Free Radicals; D016877:Oxidants; D014810:Vitamin E; D008315:Malondialdehyde; D007770:L-Lactate Dehydrogenase; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D001219:Aspartate Aminotransferases; D006221:Halothane