松果体摘除及褪黑素对大鼠胸腺上皮细胞白细胞介素-7表达的影响

目的 探讨松果体摘除及褪黑素对大鼠胸腺上皮细胞白细胞介素7(IL-7)表达的影响及其意义.方法 1.培养大鼠胸腺上皮细胞,应用广谱角蛋白抗体进行免疫细胞化学显色鉴定;MTT法观察褪黑素(1×10-3～10-9mol/L)干预对细胞生长的影响;细胞分空白对照组、褪黑素10-8mol/L处理组和褪黑素10-6mol/L处理组,RT-PCR法观察细胞IL-7 mRNA的表达;2.选用清洁级雄性SD大鼠110只,分为正常对照组、假手术对照组、松果体摘除组、松果体摘除+褪黑素7.5ms/(kg·d)腹腔注射组和松果体摘除+褪黑素15mg/(kg·d)腹腔注射组.术后4周和8周取材,运用免疫组织化学和RT-PCR方法 观察胸腺上皮细胞IL-7表达的变化. 结果 褪黑素干预对大鼠胸腺上皮细胞的生长无显著影响,但能使IL-7 mRNA的表达水平呈剂量依赖性升高;松果体摘除对大鼠胸腺上皮细胞表达IL-7无显著影响,补充褪黑素15mg/(kg·d)4周后IL-7表达显著增高,8周后均下降至正常水平. 结论 松果体及褪黑素可能通过影响大鼠胸腺上皮细胞IL-7的表达,从而调节胸腺细胞的分化发育.

EFFECT OF PINEALECTOMY AND MELATONIN ON IL-7 EXPRESSION OF RAT THYMIC EPITHELIAL CELLS

Objective To study the effect of pinealectomy and melatonin on interleukin 7(IL-7) expression of rat thymic epithelial cells (TECs) and its physiological significance. Methods Cultured rat TECs were immunostained with anti-pan-cytokeratin; MTT was applied to investigate the growth of cultured rat TECs with melatonin treatment (1×10SUP>-3/SUP>-10SUP>-9/SUP>mol/L), semiquantitative RT-PCR was applied to assess IL-7 mRNA expression. Totally 110 clean_grade male SD rats were divided into five groups: normal control group, sham operation group, pinealectomized group, pinealectomy+75mg/(kgI>&#/I>8226;d) MLT group, pinealectomy +15mg/(kgI>&#/I>8226;d) MLT group, and took the thymus out in the 4th week and the 8th week, Immunohistochemistry and semiquantitative RT-PCR were applied to observe IL-7 expression in rat TECs. Results Melatonin made no difference on rat TECs growth, but IL-7 mRNA expression in TECs was increased by melatonin treatment in a dose dependent manner; Pinealectomy made no difference on the synthesizing of IL-7 by rat TEC, but 15mg/(kgI>&#/I>8226;d) melatonin treatment resulted in significant increasing of IL-7 expression in certain period. Conclusion pinealgland and melatonin may regulate the differentiation and development of thymocyte by IL-7 expres