Morris D D, Moore J N, Crowe N, Fischer J K
Department of Large Animal Medicine, College of Veterinary Medicine, University of Georgia, Athens 30602.
Cornell Vet. 1991 Jul;81(3):267-76.
This study evaluated the effect of dexamethasone on endotoxin-induced production of tumor necrosis factor (TNF) activity in vitro by equine peritoneal macrophages. Peritoneal macrophages from adult horses were cultured in the presence of dexamethasone (1-100 microM) for various time periods (2 hour, 0.5 hour, 0 hour) prior to the addition of endotoxin (5 ng/ml), then the secretion of TNF activity was evaluated. Macrophage supernatant concentrations of TNF activity were estimated by a modified in vitro cytotoxicity bioassay using the murine fibrosarcoma cell line, WEHI 164 clone 13. An experiment was performed to determine whether dexamethasone interfered with the cytolytic bioassay's ability to detect TNF activity. The endotoxin-induced TNF activity production by equine peritoneal macrophages was significantly reduced by co-incubation with 100 microM dexamethasone, but not by tested concentrations of dexamethasone less than 100 microM. This concentration of dexamethasone greatly exceeds those generally attained by therapeutic use of dexamethasone in horses. Preincubation time did not affect the ability of 100 microM dexamethasone to reduce TNF production by equine macrophages. The quantitation of equine TNF activity by its cytolytic bioassay was not altered by dexamethasone.
本研究评估了地塞米松对马腹膜巨噬细胞体外内毒素诱导的肿瘤坏死因子（TNF）活性产生的影响。在添加内毒素（5 ng/ml）之前，将成年马的腹膜巨噬细胞在存在地塞米松（1 - 100 microM）的情况下培养不同时间段（2小时、0.5小时、0小时），然后评估TNF活性的分泌。使用鼠纤维肉瘤细胞系WEHI 164克隆13，通过改良的体外细胞毒性生物测定法估计巨噬细胞上清液中TNF活性的浓度。进行了一项实验以确定地塞米松是否干扰细胞溶解生物测定法检测TNF活性的能力。与100 microM地塞米松共同孵育可显著降低马腹膜巨噬细胞内毒素诱导的TNF活性产生，但低于100 microM的地塞米松测试浓度则无此作用。该浓度的地塞米松大大超过了马治疗中使用地塞米松通常达到的浓度。预孵育时间不影响100 microM地塞米松降低马巨噬细胞TNF产生的能力。地塞米松未改变通过其细胞溶解生物测定法定量马TNF活性的结果。
