Tissue antioxidant status in streptozotocin-induced diabetes in rats

Abstract

Interactions between manganese (Mn) deficiency and streptozotocin (STZ)-diabetes with respect to tissue antioxidant status were investigated in male, Sprague-Dawley rats. All rats were fed either a Mn-deficient (1 ppm) or a Mn-sufficient (45 ppm) diet for 8 wk. Diabetes was then induced by tail-vein injection of STZ (60 mg/kg body weight), after which the rats were kept for an additional 4 or 8 wk. The control groups comprised rats not injected with STZ and fed either Mn-deficient or Mn-sufficient diets for a total of 12 wk. The Mn-deficient diet decreased the activities of manganese superoxide dismutase (MnSOD) in kidney and heart, and of copper-zinc superoxide dismutase (CuZnSOD) in kidney, in the non-diabetic animals. In the diabetic rats, the Mn-deficient diet induced more pronounced decreases in activities of these same enzymes, and also increased liver MnSOD activity. Plasma and hepatic vitamin E levels increased progressively with the duration of diabetes, independent of dietary Mn intake. Lipid peroxidation, as measured by H2O2-induced production of thiobarbituric acid reactive substances in erythrocytes, also increased, concomitant with decreased liver and kidney glutathione (GSH) levels. These findings demonstrate for the first time and interactive effective between Mn deficiency and STZ-diabetes, resulting in amplification of tissue antioxidant changes seen with either Mn deficiency or STZ-diabetes alone. This effect of Mn deprivation in experimental diabetes suggests a physiological role for Mn as an antioxidant nutrient.

Biofloc contribution to antioxidant defence status, lipid nutrition and reproductive performance of broodstock of the shrimp Litopenaeus stylirostris: Consequences for the quality of eggs and larvae

“…The increase of GSH and TAS contents seems associated with that one of PUFA and HUFA; antioxidant protects the animal against oxidative stress (Surai et al, 2001): stress is defined as an imbalance between antioxidant and prooxidants in favour of the last. Thompson et al (1992) obtained similar results with the rat where lipid peroxidation also increased with decreased liver and kidney GSH levels.…”

Manganese Regulates Manganese-Containing Superoxide Dismutase (MnSOD) Expression in the Primary Broiler Myocardial Cells

“…In cultured cells, Mn supplementation (15 mg daily) significantly increased lymphocyte MnSOD expression [17], Mn also induced MnSOD expression in a dose-and time-dependent manner in human breast cancer Hs578T [18]. A Mn-deficient diet has been reported to decline the activities of MnSOD in mice and rats [19,20].…”

Influence of tea drinking on manganese intake, manganese status and leucocyte expression of MnSOD and cytosolic aminopeptidase P

“…In rats, increased Mn intake increases MnSOD in certain tissues (Thompson et al, 1992;Malecki et al, 1994), while, in human subjects, Mn supplementation increases the activity of MnSOD in circulating leucocytes (Davis and Greger, 1992). It is not known, however, how the intake of dietary Mn relates to cellular MnSOD levels in free living subjects although, in combination with circulating levels of Mn, leucocyte MnSOD activity has been suggested as a biomarker of Mn status (Greger, 1998(Greger, , 1999.…”