Immunoreactivities for glutathione Emphasis Type=

Authors: Takeyuki Fujimura Hideaki Suzuki Tsuyoshi Udaka Teruo Shiomori Takanori Mori Tsuyoshi Inaba Nobuaki Hiraki Kotaro Kayashima Yoshiaki Doi

Publish Date: 2008/09/20

Volume: 41, Issue: 3, Pages: 139-

PDF Link

Abstract

Darkskinned people are known to be more tolerant of ototraumatic noise than are lightskinned people and pigmented animals are more tolerant of ototraumatic noise and aminoglycoside ototoxicity than are albino animals Such tolerance may be dependent on the local ability of detoxification and antioxidant enzymes including glutathione Stransferase GST and glutathione peroxidase GSPx In the present study we examined the difference in GST/GSPx expression in the lateral wall of the cochlea between pigmented and albino guinea pigs Eightweekold male pigmented and albino guinea pigs were killed by transcardiac perfusion with 2 paraformaldehyde The cochlear ducts were isolated further fixed with 4 paraformaldehyde decalcified and then embedded in paraffin Sections prepared at 5μm thickness were incubated with antiGSTαμπ or antiGSPx antibody reacted with Alexa Fluorconjugated secondary antibody and examined under a Carl Zeiss Axioskop 2 plus fluorescence microscope The cochlea ducts were also subjected to immunoelectron microscopy for GSTπ by the postembedment method The stria vascularis of pigmented guinea pigs was strongly immunoreactive for GSTαμπ and GSPx whereas no or only weak immunoreactivities were seen in the stria vascularis of albino guinea pigs The spiral ligament showed positive but different immunoreactivities for these enzymes between the strains Doublestained immunofluorescence micrographs for GSTπ and GSPx showed a close resemblance of localization between the two enzymes in both pigmented and albino guinea pigs At the ultrastructural level immunoreactivity for GSTπ was localized preferentially in the melanin cells of pigmented guinea pigs These results suggest that correlation between pigmentation and inner ear susceptibility is at least partially attributed to the different distribution of GST/GSPx in the stria vascularis

Keywords: