Ketosis causes serious economic losses for the modern dairy industry because it is a highly prevalent metabolic disease among cows in high-producing herds during the transition period. Due to some striking similarities between diabetes in humans and ketosis in dairy cows, there is potential for the use of methylglyoxal (MGO)—commonly used in human diabetics—as a biomarker in dairy cattle. However, currently no data are available about the presence of MGO in the serum of dairy cattle or about the characteristics of its production or its potential contribution in the pathogenesis of ketosis. To determine the potential origin and pathway of formation of MGO, cows in different metabolic conditions [i.e., non-subclinically ketotic dairy cows in early lactation (n = 7), subclinically ketotic dairy cows in early lactation (n = 8), overconditioned dry cows (BCS >4.25, n = 6), and nonlactating heifers (n = 6)] were selected. Serum MGO concentrations were determined and correlated with indicators of the glucose and lipid metabolism and with haptoglobin (Hp) as an inflammatory marker. The serum MGO concentrations in subclinically ketotic cows (712.60 ± 278.77 nmol/L) were significantly greater than in nonlactating heifers (113.35 ± 38.90 nmol/L), overconditioned dry cows (259.71 ± 117.97 nmol/L), and non-subclinically ketotic cows (347.83 ± 63.56 nmol/L). In serum of lactating cows, concentrations of glucose and fructosamine were lower than in heifers and were negatively correlated with MGO concentrations. Even so, concentrations of metabolic and inflammatory markers such as dihydroxyacetone phosphate, nonesterified fatty acids, β-hydroxybutyrate, acetone, and Hp were remarkably higher in subclinically ketotic cows compared with nonlactating heifers; these metabolites were also positively correlated with MGO. In human diabetics elevated MGO concentrations are stated to originate from both hyperglycemia and the enhanced lipid metabolism, whereas higher MGO concentrations in subclinically ketotic cows were not associated with hyperglycemia. Therefore, our data suggest MGO in dairy cows to be a metabolite produced from the metabolization of acetone within the lipid metabolization pathway and from the metabolization of dihydroxyacetone phosphate. Furthermore, the highly positive correlation between MGO and Hp suggests that this reactive compound might be involved in the proinflammatory state of subclinical ketosis in dairy cows. However, more research is needed to determine the potential use of MGO as a biomarker for metabolic failure in dairy cows.

酮症是现代乳品业的严重经济损失，因为它是过渡时期高产牛群中奶牛中一种高度流行的代谢病。由于人类糖尿病与奶牛酮症之间存在惊人的相似性，因此有可能使用甲基乙二醛（MGO）（通常在人类糖尿病患者中使用）作为奶牛的生物标志物。但是，目前尚无关于奶牛血清中存在MGO或MGO生产特性或其在酮症发病机理中潜在作用的数据。为了确定MGO的潜在起源和形成途径，在不同代谢条件下的母牛（即，泌乳早期的非亚临床酮症奶牛（n = 7），泌乳早期的非临床性酮症奶牛（n = 8），选择了条件过度的干奶牛（BCS> 4.25，n = 6）和非泌乳小母牛（n = 6）]。测定血清MGO浓度，并将其与葡萄糖和脂质代谢的指标以及触珠蛋白（Hp）作为炎症指标相关联。亚临床酮症奶牛的血清MGO浓度（712.60±278.77 nmol / L）显着高于非泌乳小母牛（113.35±38.90 nmol / L），条件过度的干奶牛（259.71±117.97 nmol / L）和非亚临床酮症奶牛（347.83±63.56nmol / L）。泌乳母牛的血清中葡萄糖和果糖胺的浓度低于小母牛，并且与MGO浓度呈负相关。即使如此，新陈代谢和炎症标记物的浓度，例如磷酸二羟基丙酮，非酯化脂肪酸，β-羟基丁酸酯，丙酮，与非泌乳小母牛相比，亚临床型酮症奶牛的Hp和Hp显着更高。这些代谢物也与MGO呈正相关。在人类糖尿病患者中，据称升高的MGO浓度来自高血糖症和脂质代谢增强，而亚临床型酮症奶牛中较高的MGO浓度与高血糖症无关。因此，我们的数据表明，奶牛中的MGO是脂质代谢途径中丙酮代谢和磷酸二羟基丙酮代谢产生的代谢产物。此外，MGO和Hp之间的高度正相关表明该反应性化合物可能与奶牛亚临床酮症的促炎状态有关。然而，