Effects of the hyperbaric oxygen treatment on the Na+,K+ -ATPase and superoxide dismutase activities in the optic nerves of global cerebral ischemia-exposed rats.
The effects of hyperbaric oxygen (HBO) treatment on the Na+,K+ -ATPase and superoxide dismutase (SOD) activities were examined in the optic nerves of the rats exposed to global cerebral ischemia. Animals were exposed to global cerebral ischemia of 20-min duration and were either sacrificed or exposed to the first HBO treatment immediately, 0.5, 1, 2, 6, 24, 48, 72 or 168 h after ischemic procedure (for Na+,K+ -ATPase activities measurement) or 2, 24, 48 or 168 h after ischemia (for SOD activities measurement). HBO procedure was repeated for 7 consecutive days. It was found that global cerebral ischemia induced a statistically significant decrease in the Na+,K+ -ATPase activity of the optic nerves, starting from 0.5 to 168 h of reperfusion. Maximal enzymatic inhibition was registered 24 h after the ischemic damage. The decline in the Na+,K+ -ATPase activity was prevented in the animals exposed to HBO treatment within the first 6 h of reperfusion. The results of the presented experiments demonstrated also a statistically significant increase in the SOD activity after 24, 48 and 168 h of reperfusion in the optic nerves of non-HBO-treated ischemic animals as well as in the ischemic animals treated with HBO. Our results indicate that global cerebral ischemia induced a significant alterations in the Na+,K+ -ATPase and SOD activities in the optic nerves during different periods of reperfusion. HBO treatment, started within the first 6 h of reperfusion, prevented ischemia-induced changes in the Na+,K+ -ATPase activity, while the level of the SOD activity in the ischemic animals was not changed after HBO administration.
Mrsić-Pelcić
Jasenka
J
Department of Pharmacology, School of Medicine, University of Rijeka, Brace Brancheta 20/1, 51 000, Croatia. Jasenka.Mrsic@medri.hr
Pelcić
Goran
G
Peternel
Sandra
S
Pilipović
Kristina
K
Simonić
Ante
A
Zupan
Gordana
G
D000255:Adenosine Triphosphate / Q000096:biosynthesis; D000818:Animals; D002545:Brain Ischemia / Q000201:enzymology*; D006931:Hyperbaric Oxygenation; D009900:Optic Nerve / Q000187:drug effects / Q000201:enzymology*; D016877:Oxidants / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D015427:Reperfusion Injury / Q000201:enzymology; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism*; D013482:Superoxide Dismutase / Q000378:metabolism*; D013481:Superoxides / Q000378:metabolism
D016877:Oxidants; D013481:Superoxides; D000255:Adenosine Triphosphate; D013482:Superoxide Dismutase; D000254:Sodium-Potassium-Exchanging ATPase