Serum Antioxidant Status in Streptozotocin-Induced Diabetic Rat

Abstract

To determine whether decrease in serum antioxidants contributes to the increased oxidative stress, we measured the antioxidant activity (AOA), total peroxyl radical-trapping antioxidant parameter (TRAP), and their component individual antioxidants in the serum of diabetic rats. AOA was assayed as the ability of serum to inhibit lipid autoxidation in brain homogenates. TRAP was assayed as the ability to delay lipid peroxidation induced by an azo initiator. Antioxidants measured were ceruloplasmin, unsaturated iron binding capacity (UIBC) and albumin as components of AOA; and uric acid, protein sulfhydryl and alpha-tocopherol as components of TRAP. AOA was decreased markedly in the diabetics due to the decrease in ceruloplasmin, UIBC and albumin. On the other hand, the directly measured TRAP in the diabetics was unaltered. Uric acid and alpha-tocopherol were increased in the diabetics. However, decrease in unidentified scavengers offset the increase brought about by those antioxidants These results suggest that the decreased metal binding capacity contributes to the increased oxidative stress in the diabetic rats.

Remnant B-cell-stimulative and anti-oxidant effects of <i>Persea americana</i> fruit extract studied in rats introduced into streptzotocin-induced hyperglycaemic state

“…Statistical significance was compared between the groups as follows: a diabetic rats were compared to the control rats; b avocado-treated diabetic rats were compared to the diabetic rats ; c gliclazidetreated diabetic rats were compared to the diabetic control rats. (Asayama et al, 1994) which act as a biochemical diagnostic marker of renal impairment and drug-induced toxicity (Braunlich et al, 1997). Upon treatment wit P. americana fruit extract, the observed alterations in blood urea and serum creatinine levels in hyperglycaemic rats reverted to near normal, indicating the renal-protective nature of the extract as oppose to glucose toxicity.…”

Dual Role of Insulin in Transcriptional Regulation of the Acute Phase Reactant Ceruloplasmin

“…Animal models of diabetes provide additional insights. In both alloxan-and streptozotocin-induced diabetic rats, the decrease in insulin level is accompanied by substantial reductions in plasma Cp (73)(74)(75), and treatment of diabetic rats with insulin restores plasma Cp to normal levels (75). Similarly, treatment of rats with streptozotocin decreases Cp synthesis by the isolated perfused liver, but is restored to normal after treatment of the rats with insulin (76).…”

&alpha;-Tocopherol Status and Altered Expression of &alpha;-Tocopherol-Related Proteins in Streptozotocin-Induced Type 1 Diabetes in Rat Models

“…In the current study, plasma a-tocopherol levels decreased in the STZ rat models with type 1 diabetes. The results on the circulatory a-tocopherol levels in rodent models with type 1 diabetes are conflicting, indicating that a-tocopherol levels increase, remain unchanged, or decrease in type 1 diabetes (22)(23)(24). This discrepancy among the reports can be explained on the basis that a-tocopherol levels can probably be influenced by the experimental conditions, including the duration and stage of diabetes and the diet of diabetes patients/ study models (25).…”

“…Here we analyzed the a-tocopherol status, as well as the levels of a-tocopherol-related proteins, including binding proteins and metabolic enzymes, in insulin-dependent type 1 diabetes induced using streptozotocin (STZ) in rat models. STZ causes b-cell toxicity and leads to a hypoinsulinemichyperglycemic state (6). STZ has been widely used to induce experimental insulin-dependent diabetes in rodents.…”