Distribution of Thiol-specific Antioxidant Protein Immunoreactivity in the Mammalian Central Nervous Systern

ABSTRACT

Thiol-specific antioxidant protein (TSA) is the antioxidant protein which specifically inhibits the inactivation of various enzymes by a nonenzymatic mixedfunction oxidation (MFO) system containing a sulfhydryl compound as reducing equivalent but not by the MFO system containing a nonsulf hydryl reducing equivalent. TSA was isolated and purified from Saccharomyces cerevisiae and bovine brain. But localization in the brain and physiological role of TSA as an antioxidant enzyme a-re known very little. The localization of TSA protein in the rat brain and rabbit spinal cord was examined with polygonal antibodies to bovine TSA made in rabbit. Tissues were fixed with 4% paraformaldehyde, frozen in dry ice, sectioned on a sliding microtome, incubated with these antibodies, and then processed for avidin-biotin peroxidase complex staining. The irrimunoreactive (IR) cellular element for TSA in the central nervous system - ne-om The IR product for TSA was mainly located m neuronal soma and proximal part of neuronal process such as apical dendnte of pyranudal cell of the cerebral cortex. The glial cell, blood vessel and nucleus of neuron did not show the TSA IR TSA IR neurons were found at every nucleus and cortex mcluding cerebral cortex, hippocampus, corpus striatum, cerebellar cortex, thalamus, septum and spinal gray matter. In hypoxia rabbit spinal cord, there were dense and light IR neurons, and the former was considered to be miured by hypoxic msult These results indicate that TSA is ubiquitous protem in neurons of mammalian central nervous system and show uneven distribution among individual neurons in same nucleus and different nucleus. And TSA may be induced by increased oxidative pressure after ischemia.