Background

Lysyl oxidase (LOX) is a metalloenzyme that requires Cu as a cofactor and it is responsible for the formation of collagen and elastin cross-linking. The objective of this work was to measure the LOX enzyme activity in the heart of bovines with Cu deficiency induced by high molybdenum and sulfur levels in the diet.

Methods

Eighteen myocardial samples were obtained from Cu-deficient (n = 9) and control (n = 9) Holstein bovines during two similar assays. The samples were frozen in liquid nitrogen and stored at −70 °C to measure enzymatic activity. A commercial kit was used, following producer instructions.

Results

The results showed that LOX activity from the hearts of Cu-deficient bovines is 29 % lower than the ones of control bovines, being this difference statistically significant (p = 0.03).

Conclusion

To our knowledge, this is the first report that determined LOX enzymatic activity in bovine heart of Cu-deficient animals. The microscopic alterations found in these animals in our previous work, could be explained by a diminished LOX activity. The results are in agreement with other authors, who found a relationship between LOX activity and dietary Cu intake. The information provided by this work could help to clarify the pathogenesis of cardiac lesions in cattle with dietary Cu deficiency.

中文翻译：

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降低缺铜牛心脏中赖氨酰氧化酶的活性

背景

赖氨酰氧化酶 (LOX) 是一种金属酶，需要 Cu 作为辅助因子，它负责胶原蛋白和弹性蛋白交联的形成。这项工作的目的是测量日粮中钼和硫含量高导致铜缺乏的牛心脏中的 LOX 酶活性。

方法

在两次类似的测定中，从缺铜 (n = 9) 和对照 (n = 9) 荷斯坦牛获得了 18 个心肌样本。样品在液氮中冷冻并储存在-70°C以测量酶活性。按照生产商的说明使用商业试剂盒。

结果

结果表明，缺铜牛心脏的 LOX 活性比对照牛的心脏低 29%，这种差异具有统计学意义（p = 0.03）。

结论

据我们所知，这是第一份确定缺铜动物牛心脏中 LOX 酶活性的报告。在我们之前的工作中在这些动物中发现的微观变化可以用 LOX 活性降低来解释。结果与其他作者一致，他们发现 LOX 活性与膳食铜摄入量之间存在关系。这项工作提供的信息有助于阐明日粮铜缺乏的牛心脏病变的发病机制。