NEUROPROTECTIVE EFFECTS OF GLUTATHIONE ON RAINBOW-TROUT OLFACTORY RECEPTOR NEURONS DURING EXPOSURE TO COPPER-SULFATE

In this study glutathione (GSH) provided in vivo neuroprotection for o lfactory receptor neurons (ORN) from copper sulfate, a toxicant that a ccessed the olfactory epithelium directly from the environment into th e nasal cavity. When copper sulfate (50 mu g/l) was added to the water in trout holding tanks, ORN with elevated GSH were abundant after 1.5 hr. These later diminished, and membranous material accumulated in th e mucociliary complex. After 3 hr, vacuoles formed in the olfactory ep ithelium and ORN appeared constricted and distorted. This damage was a ccelerated and potentiated when diethyl maleate was injected to deplet e GSH levels. When fish that were pretreated with N-acetylcysteine to augment GSH were exposed to copper sulfate for 3 hr, ORN with elevated GSH remained prominent and histopathological changes were averted. Th e fact that ORN with elevated GSH preceded histopathological changes i n the olfactory epithelium and that depletion of GSH hastened these ch anges supports the view that elevated GSH localizes in ORN that are ch allenged by toxic compounds and that GSH provides protection from dege nerative changes. (C) 1997 Elsevier Science Inc.