Antioxidant status in experimental type 2 diabetes mellitus: effects of glibenclamide and glipizide on various rat tissues

Effect of the new thiazolidinedione-pioglitazone on the development of oxidative stress in liver and kidney of diabetic rabbits

“…The activity of catalase in diabetic kidney was higher than control or not affected, in agreement with a number of other studies (Kakkar et al, 1997;Tagami et al, 1992;Matkovics et al, 1997/98;Reddi and Bollineni, 1997). There is also report, which demonstrates that CAT activity in diabetic kidney is diminished (Tüzün et al, 1999). It may reflect the known sensitivity of this enzyme to radical induced inactivation.…”

“…During the persistent hyperglycemia the concentrations of H 2 O 2 may be much higher then usually which could lead to induction of CAT activity (Kakkar et al, 1997). There are also reports, which demonstrate a diminished activity of CAT in diabetic liver (Tagami et al, 1992;Tüzün et al, 1999). After pioglitazone treatment the catalase activity in the liver was normalized to control values after 4 and 8 weeks of experiment.…”

“…The intensification of peroxidation process in diabetic kidney was confirmed in other experiments (Sun et al, 1999, Akkus ß et al, 1996. Some observations indicate a good correlation between lower lipid peroxidation and higher antioxidant status (Tüzün et al, 1999). Perhaps, the lack of rise in hepatic LPO level is associated with the high concentration of ascorbic acid.…”

Modification of cardiac oxidative stress in alloxan-induced diabetic rabbits with repaglinide treatment

“…In the present study, administration of repaglinide prevents this increase of CAT activity. In other studies, CAT activity was normalized in tissues of type 2 diabetic animals by glibenclamide and glipizide treatments (Tüzü n et al, 1999).…”

“…On the other hand, repaglinide acts in the mechanism similar to that of sulfonylureas. As was stated above, some of them were reported to possess the antioxidative properties (Jennings and Belch, 2000;Tüzü n et al, 1999).…”