CHANGES OF GROWTH-INHIBITORY FACTOR AFTER STAB WOUNDS IN RAT-BRAIN

The growth inhibitory factor (GIF) is a new metallothionein (MT)-like protein that is downregulated in Alzheimer's disease (AD) brain. The b iological function of GIF has not been fully clarified yet. We have ra ised an antibody to the synthetic polypeptide that is specific for rat GIF. The purified antibody reacted to recombinant GIF and native rat GIF but not to MT or maltose-binding protein. Using the antibody and G IF cDNA probe, we investigated changes of GIF and GIF mRNA by Western and Northern blotting techniques in rat brains after stab wounds. The levels of GIF and GIF mRNA began to increase 4 days postoperation, rea ched a maximum at 14-21 days and sustained the increased level at leas t through 28 days. While both glial fibrillary acidic protein (GFAP) a nd GIF were recognized in astrocytes, the increases of these 2 protein s after stab wounds showed different patterns. The results indicated t hat GIF could play an important role in the repair after brain damage and also produce new insights into the mechanism of gliosis investigat ed mainly from the viewpoint of GFAP.