Endothelial cell endurance to various courses of focal brain ischemia-reperfusional injury in rats

Xiaofan CHU; Xuejun FU; Chuanjie QI; Kefu MA; Xuechang XIAO; Jian PENG

ABSTRACT

BACKGROUND:

Endothelial cell structural and functional integrity is importnat decisive fatcor for ischemic time-window and hemorragic transformation follwing brain ischemic injury.

OBJECTIVE:

To investiagte the endotheliocyt endurance to various course of ischemic injury basing on dynamical observation of morphological and ultrastructural changes of endotheliocyte during IR injury.

DESIGN:

Randomized controlled experiment.

SETTING:

Neurological Internal Department of the Second Affiliated Hospital of Jinan University.MATERIALS This experiment was carried out in the Animal Experimental Laboratory of the Second Affiliated Hospital of Jinan University from March 1998 to March 1999. Totally 53 SD rats were randomly dihours of 6 rats.

METHODS:

Thread-bolt occlusion method was used to establish focal brain ischemia model on rats. Brain tissue was evenly cut into five coronary segments namely A, B, C, D and E, segments C underwent TTC staining for marginal region location. segments D was taken for routine dehydration, transparency, envelop, slice and HE staining,optical microscopic observation. Ischemic surrounding area and central brain tissues was obtained from slice B, fixed and enveloped before cutting into ultrathin slices that was observed under transmission electron microscope.the occurring time of hemorrhagic infarction at different ischemic time cell vacuolization degree in foot process layer at different ischemic time points.

RESULTS:

Totally 53 rats were enrolled in this experiment and all data was entered into results analysis. Under optical microscope Neuropil loose and small vascular surrounding edema was observed at ischemia 3 hours.Small arterial broken and hemorrhage occurred at ischemia 12 hours reperfusion 3 hours. Under electron microscope Capillary endothelial nuclear swelling was observed at ischemia 3 hours, with cytoplasmic pinocytosi increasing and vacuolization in foot process layer appearing+; At ischemia 3 hours reperfusion 3 hours, the foot process layer vacuolization in center area was (++) and (+++) in marginal area; while at ischemia 6 hours reperfusion 3 hours, endothelia tight junction opened and vacuolization in foot process layer was (+++); pinocytosis was found obviously reduced after ischemia 12 hours reperfusion 3 hours, mitochondrial swelling was seldom observed, but tight junction increasingly opened and vacuolization in foot process layer appeared (+++) - (++++).

CONCLUSION:

Obvious structural changes of endotheliocyte appeared in post-ischemia 3 hours, endotheliocyte tight junction openning was observed at ischemia 6 hours, and hemorrage transformation occurred after ischemia 12 hours, mainly at the post-reperfusional ischemia center.