Effect of hyperthermia on glutathione peroxidase and lipid peroxidative damage in liver

Abstract

1. 1.|Significant lipid peroxidation occurred both in rat and guinea pig liver in passive hyperthermia caused by a hot environment. In guinea pig, lipid peroxidation was greatly induced not only in liver homogenate but also in intracellular structures, such as mitochondria and microsomes. 2. 2.|In rat, hepatic cytosolic selenium glutathione peroxidase activities were greatly induced in hyperthermia, while hepatic cytosolic glutathione peroxidase activities in guinea pig were not affected in hyperthermia. 3. 3.|In both animals, hepatic cytosolic glutathione S-transferase, cytosolic superoxide dismutase, and catalase activities were not affected. 4. 4.|Since the peroxidation of lipids in biological membranes is a destructive phenomenon and is associated with a variety of cellular damage, hyperthermia greatly developed hypertrophy and vacuolized degeneration in hepatic cells. 5. 5.|In guinea pig, the activities of hepatic mitochondrial electron transport system, such as cytochrome c oxidase and cytochrome c reductase system were simultaneously inhibited in hyperthermia. 6. 6.|On the other hand, hepatic microsomal electron transport system, such as cytochrome P450 and aminopyrine N-demethylase activities were not seriously affected by hyperthermia. 7. 7.|In nuclei and mitochondria, 90-kDa heat shock induced proteins markedly expressed in liver. 8. 8.|Since hyperthermia greatly induces lipid peroxidation in liver, heat stress may have a potential impact on peroxidative damage in humans and animals.