Osteoarthritis (OA) is one of the main locomotor disorders in horses. Although nonsteroidal anti-inflammatory drugs are the first-line treatment for OA, opioids could also be used. In previous studies, opioids showed promising anti-inflammatory and analgesic effects. In this study, we aimed to investigate the effects of two opioids (morphine and methadone) against inflammation in lipopolysaccharide (LPS)-stimulated synoviocytes by analyzing microsomal prostaglandin E synthase-1 (mPGES-1) and prostaglandin-endoperoxide synthase 2 (PTGS2) expression. Synoviocytes were obtained from the joints at the distal limbs of dead animals. The cytotoxic effects of LPS, morphine, and methadone were investigated by using a cell viability assay with crystal violet dye. Synoviocytes were treated with LPS, LPS plus morphine, or LPS plus methadone for 3, 6, and 12 h, and mPGES-1 and PTGS2 expression was measured using real-time polymerase chain reaction. LPS, and morphine did not affect the viability of synoviocytes, even at high concentrations. LPS treatment increased mPGES-1 and PTGS2 expression, whereas morphine inhibited the increase in mPGES-1 and PTGS2 expression in LPS-stimulated synoviocytes. Methadone did not inhibit mPGES-1 or PTGS2 expression. These results suggest that morphine may exhibit anti-inflammatory effect; therefore, it might be beneficial for the treatment of OA.

骨关节炎（OA）是马的主要运动障碍之一。尽管非甾体类抗炎药是OA的一线治疗药物，但也可以使用阿片类药物。在以前的研究中，阿片类药物显示出有希望的消炎和镇痛作用。在这项研究中，我们旨在通过分析微粒体前列腺素E合酶1（mPGES-1）和前列腺素内过氧化物合酶2（PTGS2），研究两种阿片类药物（吗啡和美沙酮）对脂多糖（LPS）刺激滑膜细胞炎症的影响。表达。从死动物远端肢体的关节获得滑膜细胞。LPS，吗啡和美沙酮的细胞毒性作用通过使用结晶紫染料的细胞生存力测定进行了研究。用LPS，LPS加吗啡或LPS加美沙酮处理滑膜细胞3、6和12小时，使用实时聚合酶链反应测量mPGES-1和PTGS2的表达。LPS和吗啡即使在高浓度下也不会影响滑膜细胞的活力。LPS处理增加了mPGES-1和PTGS2的表达，而吗啡抑制了LPS刺激的滑膜细胞中mPGES-1和PTGS2的表达的增加。美沙酮不抑制mPGES-1或PTGS2的表达。这些结果表明吗啡可能具有抗炎作用。因此，对OA的治疗可能是有益的。吗啡可抑制LPS刺激的滑膜细胞中mPGES-1和PTGS2表达的增加。美沙酮不抑制mPGES-1或PTGS2的表达。这些结果表明吗啡可能具有抗炎作用。因此，对OA的治疗可能是有益的。吗啡可抑制LPS刺激的滑膜细胞中mPGES-1和PTGS2表达的增加。美沙酮不抑制mPGES-1或PTGS2的表达。这些结果表明吗啡可能具有抗炎作用。因此，对OA的治疗可能是有益的。