Effects of isoflurane on nitric oxide metabolism and oxidant status of guinea pig myocardium.
BACKGROUND
Volatile anesthetics (VAs) have been shown to enhance myocardial recovery during reperfusion, the mechanism of which has not been clarified yet. It has been supposed that this effect of VAs may appear through antioxidative mechanisms.


METHODS
Thirty guinea pigs were used in the study. There were three groups with 10 animals in each: I - control, II - isoflurane+oxygen and III - oxygen. Isoflurane (2.0% v/v) and oxygen (100%) mixture was given to the animals via a face mask in the isoflurane+oxygen group at the rate of 21 per min for 30 min a day for three consecutive days. In the oxygen group, oxygen alone (100%) was given under the same conditions as in the isoflurane+oxygen group. At the end of the experiments, the animals were killed and their hearts were removed. In the heart tissues, nitric oxide synthase (NOS) activity, nitric oxide (NO) pool (NO*+NO2-) and malondialdehyde (MDA) levels were measured.


RESULTS
NOS activity was found to be higher and the NO pool lower in the isoflurane+oxygen group compared with those of control and oxygen groups. In the oxygen group, MDA level was found to be higher compared to the other groups. There was, however, no significant difference between MDA levels of the control and isoflurane+oxygen groups.


CONCLUSIONS
Our results suggest that isoflurane prevents peroxidation reactions in heart tissue, possibly by scavenging toxic oxygen radicals produced under hyperoxygenation conditions as occurs with general anesthesia.
Durak
I
I
Department of Biochemistry, Medical Faculty, Ankara University, Turkey. durak@dialup.ankara.edu.tr
Kavutcu
M
M
Kaçmaz
M
M
Avci
A
A
Horasanli
E
E
Dikmen
B
B
Cimen
M Y
MY
Oztürk
H S
HS
D018685:Anesthetics, Inhalation / Q000494:pharmacology*; D000818:Animals; D006168:Guinea Pigs; D006321:Heart / Q000187:drug effects; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D007530:Isoflurane / Q000494:pharmacology*; D008315:Malondialdehyde / Q000378:metabolism; D009206:Myocardium / Q000378:metabolism*; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000378:metabolism; D016877:Oxidants / Q000378:metabolism*
D018685:Anesthetics, Inhalation; D016877:Oxidants; D009569:Nitric Oxide; D008315:Malondialdehyde; D007530:Isoflurane; D019001:Nitric Oxide Synthase