Effects of magnesium sulfate on Na+,K+ -ATPase and intracranial pressure level after cerebral ischemia.
In the present study, the effects of magnesium sulfate on Na+,K+ -ATPase levels and intracranial pressure (ICP) after cerebral ischemia in rabbits were studied. Thirty New Zealand rabbits were divided into three groups. Group 1 was the control group. In group 2 (untreated group) cerebral ischemia was produced by clamping bilateral common carotid arteries for 60 min but in group 3 magnesium sulfate was administered 100 mg/kg i.v. 10 min after opening the clamps. In group 1, ICP recordings were obtained 5, 60 and 120 min after craniectomy. In groups 2 and 3, ICP recordings were obtained 5 min after craniectomy but before clamping, 60 min after clamping and 60 min after opening the clamps. After taking ICP recordings, brain cortices were resected and Na+,K+ -ATPase activity was determined by subtracting the enzyme activity in the presence of ouabain from the total activity in the absence of ouabain method. There was a significant difference between Na+,K+ -ATPase levels of group 1 and group 2 (P < 0.05). There was no significant difference in Na+,K+ -ATPase levels between group 1 and 3 (P > 0.05), also preischemic ICP values were same in all groups (P > 0.05). Preischemic and postischemic ICP values were significantly different between groups 1 and 2 (P < 0.05), also postischemic (120 min) ICP values were significantly different between group 2 and group 3 (P < 0.05). ICP values correlate well with Na+,K+ -ATPase level. These results demonstrate that cerebral ischemia leads to a decrease of ATPase level in the brain and magnesium sulfate suppresses the decrease of Na+,K+ -ATPase, also magnesium sulfate treatment improves the ICP changes.
Ustun
Mehmet Erkan
ME
University of Selcuk, Meram Medicine Faculty, Neurosurgery Department Meram, Konya, Turkey.
Bariskaner
Hulagu
H
Yosunkaya
Alper
A
Gurbilek
Mehmet
M
Dogan
Necdet
N
D000818:Animals; D002545:Brain Ischemia / Q000150:complications / Q000188:drug therapy* / Q000201:enzymology; D004791:Enzyme Inhibitors / Q000494:pharmacology / Q000627:therapeutic use; D019586:Intracranial Hypertension / Q000188:drug therapy* / Q000201:enzymology* / Q000209:etiology; D008278:Magnesium Sulfate / Q000494:pharmacology / Q000627:therapeutic use*; D008297:Male; D011817:Rabbits; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors* / Q000378:metabolism*
D004791:Enzyme Inhibitors; D008278:Magnesium Sulfate; D000254:Sodium-Potassium-Exchanging ATPase