Metzger Z, Berg D, Dotan M
Department of Oral Biology,School of Dental Medicine, Tel Aviv University, Israel.
J Endod. 1997 Aug;23(8):517-21. doi: 10.1016/S0099-2399(97)80313-5.
Activated macrophages are among the major constituents of the periapical granuloma. Their state of activation may persist for long periods after the local irritant is removed and may delay resolution and repair of the lesion. The effect of activated macrophages on fibroblast growth was studied in vitro. Circular fibroblast colonies were formed using a drop containing 7.5 x 10(5) murine dermal fibroblasts and allowed to grow for 7 days. When peritoneal exudate macrophages were added (0.5-3.0 x 10(6) cells/dish) and activated in vitro by LPS (1 microgram/ml), the fibroblast colony's growth was suppressed. LPS alone, at the concentration used, had no effect on the fibroblast growth. Hydrocortisone (> or = 10(-7) M) totally reversed the suppression, when added either simultaneously with or 6, 24, or 48 h after the LPS. The efficacy of late hydrocortisone treatment suggests that its effect was through prevention of the expression of the LPS activation of the macrophages. These findings may provide a possible clue to a pharmacological modulation of the healing processes that occur in the periapical lesion once its infective source had been eliminated.
活化巨噬细胞是根尖周肉芽肿的主要组成成分之一。在局部刺激物被清除后，它们的活化状态可能会持续很长时间，并可能延迟病变的消退和修复。在体外研究了活化巨噬细胞对成纤维细胞生长的影响。使用含有7.5×10⁵只小鼠真皮成纤维细胞的一滴液体形成圆形成纤维细胞集落，并使其生长7天。当加入腹膜渗出液巨噬细胞（0.5 - 3.0×10⁶个细胞/培养皿）并通过脂多糖（1微克/毫升）在体外活化时，成纤维细胞集落的生长受到抑制。单独使用该浓度的脂多糖对成纤维细胞生长没有影响。当与脂多糖同时添加或在脂多糖处理后6、24或48小时添加时，氢化可的松（≥10⁻⁷M）完全逆转了这种抑制作用。后期氢化可的松治疗的有效性表明其作用是通过阻止巨噬细胞脂多糖活化的表达来实现的。这些发现可能为一旦根尖周病变的感染源被消除后发生的愈合过程的药理调节提供一个可能的线索。
