[Superoxide dismutase and catalase activity in HeLa 229 cells infected with Chlamydia trachomatis]. / Activités des superoxyde dismutases et de la catalase dans les cellules HeLa 229 infectées par Chlamydia trachomatis.

Cytosolic superoxide dismutase (SOD) activity was found to increase with time during HeLa cell culture, this increase being due exclusively to Mn-SOD. Infection of the cells by Chlamydia trachomatis resulted in a further enhancement of this Mn-SOD activity, whereas cytosolic catalase activity was decreased in these infected cells. Superoxide (O-2.) being able to induce Mn-SOD and to inhibit catalase, these data suggest that Chlamydia trachomatis infection could be responsible for an increase in O-2. production by the infected HeLa cells.

Hepatic catalase and superoxide dismutases after acute ethanol administration in rats.

The administration of an acute ethanol load (2.3 g/kg, IP) to rats is followed by a decrease of the hepatic activity of cytosolic catalase, a decrease which precedes a reduction in the cytosolic Cu, Zn-superoxide dismutase (SOD) activity. Desferrioxamine, an iron chelator and scavenger of superoxide radicals, administered prior to ethanol, prevents the changes in the cytosolic catalase activity, changes which are unaffected by the administration of allopurinol, an inhibitor of xanthine oxidase. These data favour the hypothesis that acute ethanol results in an overproduction of oxygen free radicals which affects primarily the cytosolic catalase activity and increases hereby susceptibility of Cu, Zn-SOD to these radicals. They suggest also that xanthine oxidase does not play a major role in oxygen radical production in the liver cytosol during acute alcohol intoxication.

Discrepancy between the different subcellular activities of rat liver catalase and superoxide dismutases in response to acute ethanol administration.

After acute ethanol administration (2.3 g/kg) peroxisomal and extra-peroxisomal catalase activities were affected in opposite directions. As long as ethanol was present, peroxisomal catalase activity was enhanced, but unaffected by amino-triazole (AT) injection. Extra-peroxisomal catalase activity was decreased during the 24hr following ethanol administration and was also inhibited after AT injection. Whereas mitochondrial manganese-dependent superoxide dismutase (Mn-SOD) was unaffected, the cytosolic Cu,Zn-SOD activity was decreased. The time-course of this decrease suggests that acute ethanol administration affects primarily extra-peroxisomal catalase activity, thus rendering cytosolic superoxide dismutase more exposed to oxygen derivatives.

Liver superoxide dismutases and catalase during ethanol inhalation and withdrawal.

Manganese superoxide dismutase (Mn-SOD) studied during ethanol vapor inhalation shows no changes during the inhalation period (4 days) and a transient increase 12 hours after ethanol withdrawal. A significant decrease in cytosolic Cu-Zn-SOD is found at the end of the inhalation period and was sustained during 48 hours following ethanol withdrawal. It is suggested that this decrease in Cu-Zn-SOD activity might be related to an inactivation of the enzyme linked to the increase in hydroxyl radical production related to ethanol metabolism. Cytosolic catalase is reduced at the end of the ethanol inhalation period. This decrease could be related to an enhanced superoxide radical concentration linked to the reduced Cu-Zn-SOD activity.