The Effect of Methylprednisolone on Energy Metabolism in Acute Experimental Ischemia

The purpose of this study is to investigate the effect of methylprednisolone(M.P.) on the alterations of ATP, sum of adenosine nucleotides and adenylate energy charge(E.C.) in the cats with acute focal ischemic cercbral edema. Thirty six cats were divided 3 experimental group ; The first group was induced acute experimental ischemia for 1 hour by occlusion of left middle cerebral artery(M.C.A.) applying the Heifetz clip through the transorbital approach under the operating microscope. The second and third groups were induced acute experimental ischemia for 3 hours and 5 hours respectively by the same method. Each group was also divided 3 subgroups ; The first, untreated group(4 cats) was left without any treatment after the acute ischemia. The second, recirculation group(4 cats) was recirculated for 2 hours after the acute ischemia. The third, treatment group(4 cats) was recirculated for 2 hours and injected M.P.(15mg/kg) at 30 minutes after occlusion initially and then injected at 90 minute interval, respectively. The experimental results are as follows. In 1-hour untreated group. ATP was reduced to 34.0%, sum of adenosine nucleotides reduced to 72.2% and adenylate E.C. reduced to 60.0% of the control value. In the recirculation group, ATP was reduced to 42.0%, sum of adenosine nucleotides reduced to 82.4% and adenylate E.C. reduced to 74.3%, In the treatment group, ATP was increased to 143.9%, sum of adenosine nucleotides increased to 153.9% and adenylate E.C. decreased to 92.9%. In 3-hour untreated group, ATP was decreased to 24.9%, sum of adenosine nucleotides to 22.9% and adenylate E.C. reduced to 58.6% of the control value. In the recirculation group, ATP reduced to 32.9%, sum of adenosine nucleotides reduced to 28.6% and adenylate E.C. reduced to 71.4%. In the treatment group, ATP reduced to 99.5%, sum of adenosine nucleotides increased to 103.5% and adenylate E.C. decreased to 84.3%. In 5-hour untreated group, ATP decreased to 5.3%, sum of adenosine nucleotides reduced to 9.0% and adenylate E.C. reduced to 58.6% of the control value. In the recirculation group, ATP decreased to 4.4%, sum of adenosine nucleotides decreased to 5.8% and adenylate E.C. decreased to 57.1%. In the treatment group, ATP was reduced to 11.2%, sum of adenosine nucleotides reduced to and adenylate E.C. reduced to 70.0%. As the results shown above, the therapeutic beneficial effects of M.P. were observed in cats of 1-or 3-hour occlusion of M.C.A with 2-hour recirculation.