Luo Zhengzhong, Yong Kang, Du Zhenlong, Huang Yixin, Zhou Tao, Ma Li, Yao Xueping, Shen Liuhong, Yu Shumin, Yan Zuoting, Cao Suizhong
Department of Clinical Veterinary Medicine, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, China.
Department of Animal Science and Technology, Chongqing Three Gorges Vocational College, Chongqing 404100, China.
Metabolites. 2023 Feb 23;13(3):333. doi: 10.3390/metabo13030333.
Dairy cows with ketosis have high circulating beta-hydroxybutyric acid (BHBA) concentrations alongside which inflammation is concomitantly developed. Tryptophan (Trp) is an essential amino acid that participates in the regulation of the inflammatory response. However, the association between Trp metabolism and inflammation in dairy cows with ketosis remains unclear. Therefore, blood samples from healthy ( = 10) and ketotic ( = 10) primiparous dairy cows were collected at the calving date and the day of ketosis diagnosis (7 days in milk (7 DIM)). Serum levels of non-esterified fatty acids (NEFA), BHBA, haptoglobin (HP), serum amyloid A (SAA), lipopolysaccharide, and cortisol were analyzed. Tryptophan and its metabolites were quantified using liquid chromatography-tandem mass spectrometry. At 7 DIM, the concentrations of NEFA, BHBA, HP, and SAA were higher and the levels of Trp, kynurenine (KYN), indoleacetic acid, indole-3-lactic acid, and 3-indoxyl sulfate were lower in the dairy cows with ketosis compared with those in the healthy cows. However, the KYN/Trp and melatonin/Trp ratios increased in the cows with ketosis. At the calving date, the serum lipopolysaccharide levels did not differ between the healthy and ketotic cows, whereas the levels of NEFA, HP, and cortisol increased in the ketotic cows. Correlation analysis showed that Trp deficiency and elevated Trp metabolism in the dairy cows occurred during ketosis. Overall, our results suggest that abnormal Trp metabolism may contribute to the pathogenesis of ketosis.
患有酮病的奶牛循环中的β-羟基丁酸（BHBA）浓度很高，同时会伴随炎症的发生。色氨酸（Trp）是一种必需氨基酸，参与炎症反应的调节。然而，酮病奶牛中色氨酸代谢与炎症之间的关联仍不清楚。因此，在产犊日期和酮病诊断日（产奶7天（7 DIM））采集了10头健康初产奶牛和10头酮病初产奶牛的血样。分析了血清中非酯化脂肪酸（NEFA）、BHBA、触珠蛋白（HP）、血清淀粉样蛋白A（SAA）、脂多糖和皮质醇的水平。使用液相色谱-串联质谱法定量色氨酸及其代谢产物。在7 DIM时，与健康奶牛相比，酮病奶牛的NEFA、BHBA、HP和SAA浓度更高，而色氨酸、犬尿氨酸（KYN）、吲哚乙酸、吲哚-3-乳酸和3-吲哚硫酸酯的水平更低。然而，酮病奶牛的KYN/Trp和褪黑素/Trp比值升高。在产犊日期，健康奶牛和酮病奶牛的血清脂多糖水平没有差异，而酮病奶牛的NEFA、HP和皮质醇水平升高。相关性分析表明，酮病期间奶牛出现色氨酸缺乏和色氨酸代谢增强。总体而言，我们的结果表明色氨酸代谢异常可能导致酮病的发病机制。
