The oxidant and antioxidant effects of 25-hydroxyvitamin D3 in liver, kidney and heart tissues of diabetic rats.
Previous studies have implicated protective effects of vitamin D on insulin secretion and pancreas beta cell function. The goal of the present study is to determine if a combination therapy of 25-hydroxyvitamin D3 and insulin had any advantage over insulin therapy alone on lipid peroxidation and antioxidant activity in the streptozotocin (STZ)-induced diabetic rat. The lipid peroxidation product, thiobarbituric acid-reacting substances (TBARS), was measured to assess free radical activity in the heart, kidney and liver tissues. The enzymatic activities of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) and catalase (CAT) were measured as indicators of antioxidation in these tissues. Sprague-Dawley rats were made diabetic with a single injection of STZ (75 mg/kg i.p.). Rats were separated into three groups, each containing 10 animals: Group 1, non-diabetic and no drug treatment was given; Group 2, diabetic rats were treated with 3 IU/day subcutaneous (s.c.) insulin; and Group 3, diabetic rats were treated with 3 IU/day (s.c.) insulin plus 1 mg/kg/day per oral (p.o.) 25-hydroxyvitamin D3 for a period of 4 weeks. At the end of the study, TBARS contents of the liver, kidney and heart tissues in Groups 2 and 3 were found to be significantly increased as compared to Group 1 (P<0.05) and kidney MDA levels in Group 3 were also significantly increased as compared to Group 2 (P<0.05). The SOD and CAT contents of the heart in Group 2 were significantly increased as compared to Groups 1 and 3 (P<0.05). GSH-Px activity was unaltered in all groups (P>0.05). We suggest that a combination of insulin with 25-hydroxyvitamin D3 treatment would not be more beneficial than the use of insulin alone in antioxidant defence of diabetic liver and kidney tissues.
Noyan
T
T
Department of Biochemistry and Clinical Biochemistry, School of Medicine, Yuzuncu Yil University, Van, Turkey. tnoyan@yyu.edu.tr
Balaharoğlu
R
R
Kömüroğlu
U
U
D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D001786:Blood Glucose / Q000032:analysis; D001835:Body Weight; D002112:Calcifediol / Q000494:pharmacology*; D002374:Catalase / Q000378:metabolism; D003921:Diabetes Mellitus, Experimental / Q000201:enzymology / Q000378:metabolism*; D005260:Female; D005979:Glutathione Peroxidase / Q000378:metabolism; D006321:Heart / Q000187:drug effects*; D007668:Kidney / Q000187:drug effects*; D008099:Liver / Q000187:drug effects*; D016877:Oxidants / Q000494:pharmacology*; D018384:Oxidative Stress; D051381:Rats; D017207:Rats, Sprague-Dawley; D013482:Superoxide Dismutase / Q000378:metabolism
D000975:Antioxidants; D001786:Blood Glucose; D016877:Oxidants; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D002112:Calcifediol