Protein composition of spinal cord and cortex from short-term spinal hemisected rats

Abstract

The protein profiles of rat spinal cord and brain were examined 12 h, and 1, 3, 7, and 14 days after a left spinal cord hemisection at T2 on SDS polyacrylamide slab gels (8 to 20% linear gradient). Compared to normal and sham-operated controls, no differences in brain proteins were detectable for somatomotor or occipital cortices for the postoperative time intervals studied. In spinal cord at early postoperative times, an increase in the intensity of bands in the regions of 15,000, 30,000, 70,000, and 80,000 molecular weight (MW) were seen at the site of lesion. Protein bands at 70,000 and 80,000 were increased in samples extending to 10 mm rostral and 14 mm caudal to the site of hemisection. The increases of these proteins in spinal cord diminished during postoperative time until 14 days postoperative when alterations of patterns in these regions were present only at the site of lesion. At 7 and 14 days after hemisection, decreases in protein bands in molecular weight regions 150,000, MW; 45 to 60,000, and 20 to 25,000 MW of 45 to 60,000 MW were noted at the site of lesion and 6 mm caudal to the lesion. Correlations could be made between the increasing bands and protein components of red blood cells and serum. Decreases in high molecular weight regions were attributed to degenerative processes. These findings have implications for previous studies of morphology, amino acid uptake, and blood-brain barrier alterations.