Noyan T, Balaharoğlu R, Kömüroğlu U
Department of Biochemistry and Clinical Biochemistry, School of Medicine, Yuzuncu Yil University, Van, Turkey.
Clin Exp Med. 2005 May;5(1):31-6. doi: 10.1007/s10238-005-0061-8.
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.
以往的研究表明维生素D对胰岛素分泌和胰腺β细胞功能具有保护作用。本研究的目的是确定25-羟基维生素D3与胰岛素联合治疗在链脲佐菌素（STZ）诱导的糖尿病大鼠中，对脂质过氧化和抗氧化活性是否比单纯胰岛素治疗更具优势。通过测量脂质过氧化产物硫代巴比妥酸反应物质（TBARS）来评估心脏、肾脏和肝脏组织中的自由基活性。测量谷胱甘肽过氧化物酶（GSH-Px）、超氧化物歧化酶（SOD）和过氧化氢酶（CAT）的酶活性作为这些组织中抗氧化作用的指标。通过单次腹腔注射STZ（75 mg/kg）使Sprague-Dawley大鼠患糖尿病。将大鼠分为三组，每组10只动物：第1组，非糖尿病且未接受药物治疗；第2组，糖尿病大鼠接受3 IU/天皮下注射胰岛素治疗；第3组，糖尿病大鼠接受3 IU/天皮下注射胰岛素加1 mg/kg/天口服25-羟基维生素D3治疗，为期4周。在研究结束时，发现第2组和第3组肝脏、肾脏和心脏组织中的TBARS含量与第1组相比显著增加（P<0.05），并且第3组肾脏中的丙二醛（MDA）水平与第2组相比也显著增加（P<0.05）。第2组心脏中的SOD和CAT含量与第1组和第3组相比显著增加（P<0.05）。所有组中的GSH-Px活性均未改变（P>0.05）。我们认为，在糖尿病肝脏和肾脏组织的抗氧化防御中，胰岛素与25-羟基维生素D3联合治疗并不比单独使用胰岛素更有益。
