Abstract：
L-Selenomethionine is one of the important organic selenium sources. The supplementation of L-selenomethionine in diets is significant to improve the health of pigs. Ammonia is a major pollutant in the atmosphere and piggery, posing a threat to human and animal health. Although ammonia exposure can damage the heart, the mechanism of cardiac toxicity by ammonia is still unknown. In this study, we investigated the mechanism of cardiac injury induced by ammonia exposure in pigs and the protective effect of L-selenomethionine on its cardiotoxicity. The results showed that the blood ammonia content of pig increased significantly in ammonia group, the expressions of energy metabolism-related genes (LDHA, PDK4, HK2, and CPTIB) and the oxidative stress indexes were significantly changed (P < 0.05), the AMPK/PPAR-γ/NF-κB signaling pathways were activated, the chromatin edge aggregation and nuclear pyknosis were observed in ultrastructure, the apoptotic cells were significantly increased (P < 0.05), and the mRNA and protein expressions of apoptosis-related genes (Bcl-2, Bax, Cyt-c, caspase-3, and caspase-9) were significantly affected (P < 0.05). The above changes were significantly alleviated in ammonia + L-selenomethionine group, but there were still significant differences compared with the C group (P < 0.05). Our results indicated that ammonia exposure could cause energy metabolism disorder and oxidative stress and induce apoptosis of cardiomyocytes through AMPK/PPAR-γ/NF-κB pathways, which could lead to cardiac injury and affect cardiac function. L-Selenomethionine could effectively alleviate the cardiac damage caused by ammonia and antagonize the cardiotoxicity of ammonia.
摘要：
L-硒蛋氨酸是重要的有机硒源之一。日粮中添加L-硒代蛋氨酸对改善猪的健康具有重要意义。氨是大气和猪舍中的主要污染物,对人类和动物健康构成威胁。尽管氨暴露会损害心脏，氨对心脏的毒性作用机制尚不清楚。在这项研究中,我们研究了氨暴露引起猪心脏损伤的机制以及L-硒代蛋氨酸对其心脏毒性的保护作用。结果表明,氨组猪血氨含量显著增加,能量代谢相关基因的表达(LDHA，PDK4，HK2和CPTIB）和氧化应激指标显着变化（P<0.05），AMPK/PPAR-γ/NF-κB信号通路被激活,超微结构观察到染色质边缘聚集和核固缩，细胞凋亡明显增多(P<0.05),以及凋亡相关基因的mRNA和蛋白表达(Bcl-2，Bax，Cyt-c,caspase-3和caspase-9)受影响显著(P<0.05)。氨+L-硒代蛋氨酸组上述变化明显缓解,但与C组相比仍有显著性差异(P<0.05)。我们的结果表明，氨暴露可以通过AMPK/PPAR-γ/NF-κB途径引起能量代谢紊乱和氧化应激并诱导心肌细胞凋亡。这可能导致心脏损伤并影响心脏功能。L-硒代蛋氨酸能有效减轻氨对心脏的损害,拮抗氨的心脏毒性。
