HEME OXYGENASE IN THE EXPERIMENTAL ALS MOUSE

Heme oxygenase-1 (HO-1) is a stress protein inducible in same cells by oxidative stress. The status of heme oxygenase was investigated in a transgenic mouse model of amyotrophic lateral sclerosis (AES) since ox idative mechanisms are postulated in neuronal injury, Three ALS mice [ (SQD1-G93A)1Gur] and three controls [(SOD-1)2Gur] mere obtained from T he Jackson Laboratory. Behavioral differences suggestive of neurodegen eration in ALS mice developed at 4-5 months of age. All mice were kill ed at 7-8 months of age. Tissue vacuolation, cell loss, and the presen ce of GFAP(+) cells were noted in the spinal cords of ALS mice. Spinal cord motor neurons in both control and ALS mice stained positive for heme oxygenase-2 (HO-2). While not precluding the presence of low leve ls of HO-1 neither immunohistochemical staining nor Western blot analy sis provided evidence for significant HO-1 induction in degenerating s pinal cord.