Ouweltjes W, de Zeeuw A C, Moen A, Counotte G H M
ASG-WUR Lelystad.
Tijdschr Diergeneeskd. 2007 Feb 1;132(3):76-83.
Serum, plasma, or urine samples are usually used for the measurement of the trace elements copper; zinc, iron, selenium, because these samples are easy to obtain; however; these samples are not always appropriate. For example, it is not possible to measure molybdenum, the major antagonist of copper; in blood or urine. Therefore measurement of trace elements in liver tissue is considered the gold standard. For the assessment of selenium the method of choice remains determination of glutathion peroxidase in erythrocytes and for the assessment of magnesium determination of magnesium in urine. We determined the accuracy and repeatability of measuring trace elements in liver biopsies and whole liver homogenates. The levels of trace elements measured were similar in both preparations (92% agreement). Liver biopsy in live animals is a relatively simple procedure but not common in The Netherlands. Reference levels of trace elements, classified as too low, low, adequate, high, and too high, were established on the basis of our research and information in the literature. In a second study we investigated the practical aspects of obtaining liver tissue samples and their use. Samples were collected from cattle on a commercial dairy farm. Liver biopsy provided additional information to that obtained from serum and urine samples. We prepared a biopsy protocol and a test package, which we tested on 14 farms where an imbalance of trace minerals was suspected. Biopsy samples taken from 4 to 6 animals revealed extreme levels of trace elements.
血清、血浆或尿液样本通常用于测量微量元素铜、锌、铁、硒，因为这些样本易于获取；然而，这些样本并不总是合适的。例如，无法在血液或尿液中测量铜的主要拮抗剂钼。因此，肝脏组织中微量元素的测量被认为是金标准。对于硒的评估，首选方法仍然是测定红细胞中的谷胱甘肽过氧化物酶，对于镁的评估，则是测定尿液中的镁。我们测定了肝活检组织和全肝匀浆中微量元素测量的准确性和可重复性。两种制剂中测量的微量元素水平相似（一致性为92%）。对活体动物进行肝活检是一个相对简单的程序，但在荷兰并不常见。根据我们的研究和文献中的信息，建立了微量元素的参考水平，分为过低、低、充足、高和过高。在第二项研究中，我们调查了获取肝脏组织样本及其用途的实际情况。样本取自一个商业奶牛场的牛。肝活检提供了从血清和尿液样本中无法获得的额外信息。我们制定了一个活检方案和一个测试包，并在14个怀疑存在微量矿物质失衡的农场进行了测试。从4至6只动物身上采集的活检样本显示微量元素水平极高。
