[An experimental model of focal brain ischemia in rats based on the endovascular microsurgery].

An endovascular model of focal brain ischemia in rats with controlled duration of reperfusion of 1h has been studied. The reliability of experimental model for localization and volume of ischemic lesion (basal ganglia, hippocampus, parietal-temporal regions; the volume of lesion focus on MRI T2-weighted image (T2-WI) in the first day after brain ischemia 146.4 +/- 44.7 mm3) has been worked out. We conducted the clinical monitoring including assessment of neurological deficit, behavioral tests and performed MRI of the brain on 1st, 5th and 10-17th days after the occlusion of middle cerebral artery (MCA), including regimes of diffusion-weighted image (DWI) and T2-WI, and carried out a histological study of the brain. The regress of neurological deficit was seen on the 14th day after surgery. Behavioral tests revealed the reduction of movement activity of animals in the case group 7 days after the MCA occlusion. Compared to the first day after surgery, the decrease of volume lesion focus on DWI and T2-WI was observed on the 5th day (p < 0.05) as well, with the following decrease to the 10-14th days. The histological picture in the lesion foci corresponded to the brain infarction on the 5th and 14th days after surgery.

Comparative evaluation of two methods for studies of experimental focal ischemia: magnetic resonance tomography and triphenyltetrazoleum detection of brain injuries.

The volumes of foci of injuries, evaluated by T2-suspended MRT images and analysis of histological sections stained by triphenyltetrazoleum chloride, were compared on a model of unilateral intravascular blocking of the middle cerebral artery branch. The two methods for evaluation of foci of lesions gave close results, correlating with the severity of neurological deficiency in animals subjected to ischemia, manifesting in behavioral tests.