Dietary zinc and metallothionein on small intestinal disaccharidases activity in mice  

作　　者：Cuong D Tran Johanna Cool Cory J Xian 

机构地区：[1]Gastroenterology Unit,Children,Youth and Women's Health Service [2]Discipline of Physiology,School of Medical Sciences,The University of Adelaide [3]Discipline of Agricultural and Animal Science,School of Agriculture,Food and Wine The University of Adelaide, Adelaide [4]Sansom Institute for Health Research,School of Pharmacy and Medical Sciences,University of South Australia

出　　处：《World Journal of Gastroenterology》2011年第3期354-360,共7页世界胃肠病学杂志（英文版）

基　　金：Supported by (in part) the MS McLeod Post-Doctoral Fellowship obtained from the Women’s and Children’s Hospital Foundation (to Tran CD)

摘　　要：AIM: To examine the effect of increasing dietary zinc (Zn) intake and the lack of metallothionein (MT) expression on activity of small intestinal disaccharidases. METHODS: MT-Ⅰ and Ⅱ knockout (MT-/-) and wild-type (MT+/+) female mice at 3.5 wk of age were randomly fed with a diet containing 2 (2 Zn), 15 (15 Zn) or 50 (50 Zn) mg Zn/kg (n = 8/group/genotype) for 5 wk. Small intestinal segments (duodenum, jejunum and ileum) were collected and either fixed in 10% formalin for histological analysis or snap frozen in liquid nitrogen for sucrase, lactase and maltase activity analyses.RESULTS: Plasma Zn was significantly (P < 0.05) lower (33%) in MT-/- compared with MT+/+ mice fed the 2 Zn diet. Villus height and crypt depth were increased by approximately 15% in MT+/+ mice compared with MT-/- mice. Duodenal disaccharidase activities were significantly higher in MT+/+ compared with MT-/- mice particularly in those fed the 2 Zn diet. For the 50 Zn diet, jejunal sucrase and lactase activities were significantly higher in MT-/- (13 313 ± 2314; 4107 ± 364 μmol glucose/well/min/g tissue, respectively) compared with MT+/+ mice (7054 ± 608; 1818 ± 174). Similarly, ileal lactase activities were higher in MT-/- (1480 ± 192) compared with MT+/+ (629 ± 353) mice particularly those fed the 2 Zn diet. CONCLUSION: Increasing dietary Zn has little effect on disaccharidases activity in MT wild-type mice. The presence of MT may enhance morphological and functional development of the gut.AIM： To examine the effect of increasing dietary zinc （Zn） intake and the lack of metallothionein （MT） expression on activity of small intestinal disaccharidases. METHODS： MT-Ⅰ and Ⅱ knockout （MT-/-） and wild-type （MT＋/＋） female mice at 3.5 wk of age were randomly fed with a diet containing 2 （2 Zn）, 15 （15 Zn） or 50 （50 Zn） mg Zn/kg （n = 8/group/genotype） for 5 wk. Small intestinal segments （duodenum, jejunum and ileum） were collected and either fixed in 10% formalin for histological analysis or snap frozen in liquid nitrogen for sucrase, lactase and maltase activity analyses.RESULTS： Plasma Zn was significantly （P 0.05） lower （33%） in MT-/- compared with MT＋/＋ mice fed the 2 Zn diet. Villus height and crypt depth were increased by approximately 15% in MT＋/＋ mice compared with MT-/- mice. Duodenal disaccharidase activities were significantly higher in MT＋/＋ compared with MT-/- mice particularly in those fed the 2 Zn diet. For the 50 Zn diet, jejunal sucrase and lactase activities were significantly higher in MT-/- （13 313 ± 2314; 4107 ± 364 μmol glucose/well/min/g tissue, respectively） compared with MT＋/＋ mice （7054 ± 608; 1818 ± 174）. Similarly, ileal lactase activities were higher in MT-/- （1480 ± 192） compared with MT＋/＋ （629 ± 353） mice particularly those fed the 2 Zn diet. CONCLUSION： Increasing dietary Zn has little effect on disaccharidases activity in MT wild-type mice. The presence of MT may enhance morphological and functional development of the gut.

关 键 词：LACTASE MALTASE SUCRASE METALLOTHIONEIN DIET ZINC 

分 类 号：R574[医药卫生—消化系统]