Department of Paraclinical Sciences, Faculty of Veterinary Science, University of Pretoria, Pretoria, South Africa.
Electron Microscope Unit, Department of Anatomy and Physiology, Faculty of Veterinary Science, University of Pretoria, Pretoria, South Africa.
PLoS One. 2024 Sep 25;19(9):e0311046. doi: 10.1371/journal.pone.0311046. eCollection 2024.
Carboxylic ionophores are polyether antibiotics used in production animals as feed additives, with a wide range of benefits. However, ionophore toxicosis often occurs as a result of food mixing errors or extra-label use and primarily targets the cardiac and skeletal muscles of livestock. The ultrastructural changes induced by 48 hours of exposure to 0.1 μM monensin, salinomycin, and lasalocid in cardiac (H9c2) and skeletal (L6) myoblasts in vitro were investigated using transmission electron microscopy and scanning electron microscopy. Ionophore exposure resulted in condensed mitochondria, dilated Golgi apparatus, and cytoplasmic vacuolization which appeared as indentations on the myoblast surface. Ultrastructurally, it appears that both apoptotic and necrotic myoblasts were present after exposure to the ionophores. Apoptotic myoblasts contained condensed chromatin and apoptotic bodies budding from their surface. Necrotic myoblasts had disrupted plasma membranes and damaged cytoplasmic organelles. Of the three ionophores, monensin induced the most alterations in myoblasts of both cell lines.
羧酸离子载体是一种多醚类抗生素，被广泛用作生产动物的饲料添加剂，具有多种益处。然而，由于饲料混合错误或标签外使用，常常会发生离子载体中毒，主要影响牲畜的心脏和骨骼肌。本研究采用透射电子显微镜和扫描电子显微镜，研究了体外暴露于 0.1 μM 莫能菌素、盐霉素和拉沙里菌素 48 小时对心肌（H9c2）和骨骼肌（L6）成肌细胞的影响。离子载体暴露导致线粒体浓缩、高尔基器扩张和细胞质空泡化，在成肌细胞表面呈现凹陷。超微结构显示，离子载体暴露后既有凋亡的成肌细胞，也有坏死的成肌细胞。凋亡的成肌细胞含有浓缩的染色质和从其表面出芽的凋亡小体。坏死的成肌细胞的质膜破裂，细胞质细胞器受损。在这三种离子载体中，莫能菌素对两种细胞系的成肌细胞诱导的变化最大。
