VC与VD_3联合应用对结肠炎豚鼠肠粘膜保护作用

Effect of vitamin D_3 combined with vitamin C on intestinal permeability in guinea pigs with colitis

目的探讨不同剂量维生素C(VC)联合维生素D3(VD3)对结肠炎豚鼠肠粘膜通透性的影响。方法24只雄性Dunkin-Hartley豚鼠适应性喂养7 d后,按体重随机分为4组,每组6只:对照组(100 mg/kg VC)、模型组(100 mg/kg VC)、低、高剂量VC组(10、200 mg/kg VC),采用改良豚鼠灌胃方法给予各组豚鼠剂量为200 IU/kg的VD3,同时按组别给予相应剂量VC,连续5周;模型组、低、高剂量VC组豚鼠自由饮用2%葡聚糖硫酸钠(DSS)溶液4 d,对照组豚鼠自由饮用蒸馏水。采用放射免疫法检测血清中25-(OH)D3和1,25-(OH)2D3水平,酶联免疫法检测血清中二胺氧化酶(DAO)、D–乳酸和内毒素含量;取远端结肠组织,常规石蜡包埋,苏木素–伊红(HE)染色,显微镜下观察,进行组织病理学评分。结果与对照组比较,模型组、低、高剂量VC组豚鼠结肠大体形态评分和组织病理学评分均明显升高(P<0.05);与对照组比较,模型组、低、高剂量VC组豚鼠血清中DAO含量[分别为(252.02±1.74)、(253.06±2.54)(250.60±0.82)U/m L]均明显升高(P<0.05),低、高剂量VC组豚鼠血清中内毒素水平[分别为(109.74±13.37)、(111.58±12.49)EU/m L]均明显降低(P<0.05)。结论在一定剂量的维生素D3基础上,VC对结肠炎豚鼠肠粘膜屏障功能具有一定保护作用。

Objective To investigate the effect of vitamin C （VC） combined with vitamin D3 （VD3） on intestinal permeability in guinea pigs with dextran sulfate sodium （DSS）-induced colitis. Methods Twenty-four male Dunkin-Hartley guinea pigs were randomly divided into four groups （6 in each group） according to their weight after one week acclimatization： normal （N） group with 200 international unit （IU）/kg VD3 ＋ 100 mg/kg VC, model （M） group with 200 IU/kg VD3 ＋ 100 mg/kg VC, low VC （LC） groupwith, 200 IU/kg VD3 ＋ 10 mg/kg VC, and high VC （HC） group with 200 1U/kg VD3 ＋ 200 mg/kg VC. All the pigs were fed with a vitamin D3- and vitamin C-deficient feed and the corresponding doses of VC and VD3 were given by gavage for 5 weeks. Then the pigs of the N group were supplied with distilled water and the other 3 groups were supplied with 2% dextran sodium sulfate solution for 4 days. The pigs＇ serum 25-hydroxycholecalciferol （25-（OH） D3） and 1, 25-dihydroxyvitamin D3 （1, 25-（OH）2D3） were detected with radioimmunoassay and serum diamine oxidase （DAO）, D-lactic acid, and lipopolysaccharide （LPS） were measured with enzyme-linked immunosobent assay （ELISA）. Distal colon tissue samples of the pigs were collected and examined with microscope for pathological scaling after paraffin embedding and haematoxylin-eosin （HE） staining. Results The pathological score of the distal colon tissues increased significantly in the pigs of M, LC, and HC groups than that in the pigs of N group （P 〈 0.05 for all）. The serum DAO was 252.02 ± 1.74 U/ml for the pigs of M group, 253.06± 2.54 U/ml for LC group, and 253.06 ± 2.54 U/ml for HC group, respectively, significantly higher than that for N group （all P 〈 0.05）; the serum LPS was significantly decreased to 109.74 ± 13.37 EU/mL for the pigs of LC group and to 111.58 ± 12.49 EU/mL for HC group （both P 〈 0.05）. Conclusion Administration of vitamin C combined with a certain dose of vitamin D3 could protect intestinal mucosal barrier function in guinea pigs with DSS-induced colitis.