CHANGES OF BETA-AMYLOID PRECURSOR PROTEIN AFTER COMPRESSION TRAUMA TOTHE SPINAL-CORD - AN EXPERIMENTAL-STUDY IN THE RAT USING IMMUNOHISTOCHEMISTRY

We evaluated by immunohistochemistry the changes of beta-amyloid precu rsor protein (beta APP) and beta-amyloid peptide (beta A) in the spina l cord of rats with compression injury at Th-8-9 of mild, moderate, an d severe degrees, The spinal cord of normal rats and animals with lami nectomy revealed immunoreactivity to beta APP in nerve cell bodies, th e initial part of a few axons of the gray matter, and in scattered gli al cells. At 4 h after compression, beta APP-immunoreactivity occurred in a few swollen axons of the longitudinal tracts; such beta APP-immu noreactive axons remained throughout the experimental period of 9 days , The number of immunoreactive axons and the intensity of their immuno reactivity were increased in rats with moderate and severe compression , The caudal Th-10 segment exhibited more pronounced accumulation of b eta APP immunoreactivity than the cranial Th segment, There was no evi dence of beta A accumulation after compression injury. In conclusion, there is a rapidly occurring, long-lasting accumulation of immunoreact ive beta-amyloid precursor protein after compression injury of rat spi nal cord, This accumulation is related to the degree of impact to the cord.