【摘要】 目的探讨松果体及其褪黑素对胸腺细胞死亡信号通路的影响。方法选用清洁级SD大鼠,分为正常对照组、假手术对照组、松果体摘除组、松果体摘除+褪黑素腹腔注射7.5 mg/（kg.d）组和松果体摘除+褪黑素腹腔注射15 mg/（kg.d）组。术后4、8周取材。运用免疫细胞化学ABC法染胸腺Fas/FasL、caspase₈、caspase₁2阳性细胞,计算机图像分析测量阳性细胞面积及其染色强度。以RT-PCR法检测褪黑素干预原代培养胸腺细胞TNF-β的表达。结果松果体摘除后胸腺细胞Fas染色显示阳性细胞面积显著增大,术后4周皮质阳性细胞面积增加,有统计学意义,术后8周其差异继续扩大。FasL染色结果与Fas类似。松果体摘除后胸腺细胞caspase₈阳性细胞面积术后8周无论皮质还是髓质均显著增加,对caspase₁2影响不明显。补充褪黑素后,松果体摘除造成的各种参数的影响逐渐减弱。褪黑素处理后大鼠培养胸腺细胞TNF-β的表达明显减弱。结论松果体能通过影响胸腺细胞死亡信号通路从而调控大鼠胸腺细胞的凋亡,补充褪黑素能缓解相关影响。更多还原

【Abstract】 Objective To investigate the effect of pinealectomy and melatonin on the dead signal path of thymocyte in rat. Methods SD rats were divided into 5 groups:normal control,sham-operated control,pinealectomy,pinealectomy+melatonin injection 7.5 mg/(kg\5d);and pinealectomy+melatonin injection 15 mg/(kg\5d).The animals were sacrificed at 4 or 8 weeks after operation.Fas/FasL\,caspase-8\,caspase-12 positive cells in thymus were stained with immunocytochemical ABC method,measured by compute image analysis.The TNF-β expression in thymocyte which was influenced by melatonin was tested by RT-PCR.(Results The) area of Fas positive cells in cortex was increased significantly at 4 weeks after Px,furthermore,this trend continued to enlarge 8 weeks after Px.The result of FasL staining was similar to the Fas.The area of caspase-8 positive thymic T cells increased significantly in both cortex and medulla 8 weeks after Px,but the difference showed no significance on caspase-12.Melatonin administration attenuated the effect caused by Px.The TNF-β expression in cultured rat thymocyte was decrease by melatonin administration.Conclusion Pineal gland can regulate the apoptosis of rat thymocyte by inflence the dead signal path.Rejuvenation of degenerative thymus could be observed by melatonin administration.更多还原