Glutathione Levels during the Mosquito Life Span with Emphasis on Senescence

Abstract

Glutathione levels were determined in mosquitoes of all ages of the life span. Specific analyses for reduced (GSH) and oxidized (GSSG) glutathione were used and validated to ensure minimal autoxidation of GSH and conversion of these forms. Indeed GSH accounted for >97% of the total glutathione (GSH + GSSG) content in all samples. Marked changes occurred during the life span, and the highest levels of GSH and total glutathione were found during larval growth and metamorphosis (P < 0.001). Thereafter the levels decreased in the early adult, plateaued in the mature, and decreased 46% in the old and very old mosquito (P < 0.001). This aging-specific decrease was a general phenomenon, for it occurred in all body regions of both sexes. Starvation up to 3 days did not affect the GSH levels. The importance of these changes in glutathione is its relationship to the reducing and biosynthetic capacities of different life span stages. Of special interest is the senescence decrease which can lead to lower biosynthetic activity and also impaired detoxification capacity.