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.
Department of Pharmacology, School of Medicine, University of Rijeka, Brace Brancheta 20/1, 51 000, Croatia. Jasenka.Mrsic@medri.hr
Jasenka
J
Mrsić-Pelcić
Goran
G
Pelcić
Sandra
S
Peternel
Kristina
K
Pilipović
Ante
A
Simonić
Gordana
G
Zupan
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