Cerebral ischemia has been extensively studied in order to obtain effective therapeutic measures that might minimize its effects, since a large number of clinical or surgical patients frequently suffer irreversible consequences of this condition. The choice of a satisfactory experimental model to be used in research on neuroprotective agents has been the basis of these studies. In the present investigation, the cat was chosen as an experimental model of ischemia and the condition was evaluated on the basis of two parameters, i.e., mitochondrial respiration and swelling. The animals used in the experiment (N = 32) were divided into four groups; three groups of 10 animals each were submitted to progressively increasing periods of ischemia (15, 30 and 60 minutes), and the last group (N = 2) was not submitted to ischemia. Clear changes in the curves of energized mitochondrial swelling were observed in the animals submitted to 60 minutes of ischemia when the ischemic side was compared to the control, and this occurrence was even clearer when the antibiotic alameticin was added during the laboratory assays of swelling. It is possible to find these conclusions: swelling is an indicator of mitochondrial differentiation between tissues; brain mitochondrion when exposed to effects of alameticin presents a different sensibility if is comparison to other tissues; brain mitochondria submitted to ischemia during 60 minutes became more sensibility to alameticin; and finally, brain mitochondria have an extremely fast installation of reversion swelling.
cerebral ischemia; mitochondrial swelling
