Determination of extent of
infarction in animal models of
cerebral ischemia is most commonly achieved by either classical histology (
thionin staining) and light microscopy or staining with 2,3, 5-triphenyltetrazolium
chloride (TTC). These techniques have limitations and we now describe a novel technique and its validation for assessment of the neuroprotective activity of
AM-36, a novel arylalkypiperazine compound with combined
antioxidant and
sodium channel blocking activity.
AM-36 (1.8 mg/kg i.p.) or vehicle, was administered 30 min, 24 and 48 h after endothelin-1-induced
middle cerebral artery occlusion in conscious rats. Rats were killed at 72 h, brains removed and frozen in liquid
nitrogen prior to coronal sectioning. Using a simple apparatus relying on basic principles of light propagation and a computerised image analysis system, ischemic damage in unstained slide-mounted sections was clearly visualised and measured.
AM-36 significantly reduced the area of
infarct in both cortex and striatum. The method was verified by
thionin staining, and light microscopy. Linear regression analysis showed a highly significant correlation between methods at 72 h for
infarct area in the cortex and striatum. Highly significant correlations between methods were found at 3 and 24 h after
ischemia. Our method quickly and clearly delineates areas of damage in a manner superior to conventional staining methods.