Organic solvent soluble lipofuscin pigments and glutathione peroxidase in weanling and old rats.

Tissues from weanling and 19-month-old Sprague Dawley rats were spectrophotofluorometrically analyzed for organic solvent soluble lipofuscin pigments (OLP) and assayed for glutathione peroxidase (GSH-Px) activity. Significantly lower levels of OLP and higher levels of GSH-Px activity were found in the kidney, heart and testis at 19 months of age than were found in weanling rats. No age-related differences in OLP were observed in the brain, lung or liver. The results appeared to indicate an inverse relationship between OLP and GSH-Px activity in some tissues, but the magnitude of the changes observed coupled with conflicting observations in the liver suggested that GSH-Px activity and OLP concentrations were not directly related.