The fate of the free radical

Abstract

The influence of aging on the respiratory activity of stimulated Kupffer cells was investigated in the isolated perfused mouse liver in relation to colloidal carbon phagocytosis, and the content of glutathione (GSH) and protein carbonyls as parameters related to oxidative stress. Livers from aged (22 months) mice exhibited significant 35% and 65% decreases in the carbon uptake and in the carbon-induced O₂ consumption compared to young (3 months) animals, respectively, with a concomitant 46% diminution in the carbon-induced O₂ consumption/carbon uptake ratio. Hepatic GSH depletion was observed in aged mice compared to young animals, whereas protein oxidation was enhanced. It is concluded that aging leads to an impairment in the functional capacity of Kupffer cells reflected by a substantial reduction in their respiratory burst activity, lessened endocytic capacity and enhanced oxidative stress, that may contribute to increased susceptibility of the liver to noxious challenges.