Yamagishi N, Miyazaki M, Naito Y
Research Centre for Animal Hygiene and Food Safety, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido 080-8555, Japan.
Vet J. 2006 Mar;171(2):363-6. doi: 10.1016/j.tvjl.2004.10.021. Epub 2005 Jan 19.
Intestinal epithelial cells contain calcium-binding proteins and Ca2+-transporting adenosine triphosphatase (Ca2+-ATPase), which play important roles in intestinal Ca transport. However, the factors that affect the expression of these transepithelial Ca-transporting proteins in dairy cattle are unknown. In this study, a semi-quantitative reverse transcription polymerase chain reaction was used to determine the expression of the mRNAs for intestinal Ca-binding protein calbindin-D9k (CaBP9k), two isoforms of plasma membrane Ca2+-ATPase (PMCA1 and PMCA4), and vitamin D receptor (VDR) in duodenal tissue samples from 20 non-lactating, non-pregnant Holstein dairy cattle (0.4-135.9 months old). The correlations between the expressions of transepithelial Ca-transporting proteins, the ages of the cattle, and the presence of several plasma components were evaluated. The duodenal CaBP9k mRNA content had a significant negative correlation with age and positive correlations with plasma inorganic phosphorus (iP) and 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) concentrations. The PMCA1 mRNA content was negatively correlated with the plasma Ca concentration. The duodenal PMCA4 mRNA content was correlated negatively with the plasma iP. The VDR mRNA content had a positive correlation with the plasma magnesium concentration.
肠上皮细胞含有钙结合蛋白和钙离子转运三磷酸腺苷酶（Ca2+-ATPase），它们在肠道钙转运中发挥重要作用。然而，影响这些跨上皮钙转运蛋白在奶牛中表达的因素尚不清楚。在本研究中，使用半定量逆转录聚合酶链反应来测定20头非泌乳、未怀孕的荷斯坦奶牛（0.4 - 135.9月龄）十二指肠组织样本中肠道钙结合蛋白钙结合蛋白-D9k（CaBP9k）、质膜Ca2+-ATPase的两种同工型（PMCA1和PMCA4）以及维生素D受体（VDR）的mRNA表达。评估了跨上皮钙转运蛋白表达、奶牛年龄和几种血浆成分之间的相关性。十二指肠CaBP9k mRNA含量与年龄呈显著负相关，与血浆无机磷（iP）和1,25-二羟基维生素D3（1,25(OH)2D3）浓度呈正相关。PMCA1 mRNA含量与血浆钙浓度呈负相关。十二指肠PMCA4 mRNA含量与血浆iP呈负相关。VDR mRNA含量与血浆镁浓度呈正相关。
