高氧致新生鼠肾组织病理变化及γ-干扰素的表达

Changes of renal histology and expression of IFN-γ/of normobaric hyperoxia in neonatal rats

目的动态观察高氧诱导的慢性肺疾病新生大鼠肾组织的病理变化，检测细胞因子γ干扰素（γ-Interferon，IFN-γ）在肾组织中的变化规律，以探讨高氧对肾脏的损伤及其发生机制。方法采用高氧致新生鼠肺损伤的模型，将足月新生鼠生后分别在80％±5％氧气（n=100）和正常空气（n=100）中持续暴露，于1、3、7、14、21d各处死12只，用HE染色观察肾组织形态学改变，免疫组织化学技术动态检测肾组织中IFN-γ的表达部位和强度变化。结果病理组织学表明与空气组比较，高氧组肾脏呈轻度改变，于3、7d主要为肾小管空泡变性、水肿、扩张，在14、21d可见肾间质血管扩张、充血，偶见肾小管出血、坏死，肾小管再生，未见肾纤维化。免疫组织化学检测结果显示空气组大鼠肾组织内无或仅有少量IFN-γ阳性细胞表达，高氧组各期显示IFN-γ阳性表达的细胞广泛分布于肾小管上皮细胞。高氧组于3d肾组织IFN-γ光密度值（O．46±0．02），表达增强（P〈0．05）；7d为（0．61±0．14），表达达高峰（P〈0．01）；14天为（0．42±0．22），表达减弱，但差异仍具统计学意义（P〈0．05）；21d为（0．25±0．05），表达减弱，与对照组（0．24±O．05）比较，差异无统计学意义（P〉0．05）。结论吸入高氧的新生鼠可产生肾脏病理学轻度改变，细胞因子IFN-γ在肾脏表达一过性增强，可能参与了肾脏损伤的发生。

Objective To study changes in renal histology of neonatal rats with prolonged hyperoxic lung injury and monitored the expression of IFN-γ in kidney. Methods Full-time newborn rats were continu-ously exposed to oxygen（80%±5% 02 ,n = 100） or room air（21% 02 ,n = 100） after birth. Dynamic changes of renal histology and the expression of interferon （IFN）-γ in kidney by immunohistochemical method were mo-nitored on day 1,3,7,14,21 in the hyperoxia and control group. Results Normobaric hyperoxia indnced mild renal damage including renal tubular hydropic degeneration, edema, dilation, tubular interstitial vessel dilation, congestion, and rare tubular hemorrhage, necrosis, regeneration. Fibrosis were not seen. On day 3,7,14, the inten- sity of IFN-γ expression increased compared with the control group （ P 〈 0. 05 ） and significantly increased on day 7（P 〈0. 01 ）. IFN-γ were mainly expressed in tubular epithelia cells. On day 21 ,the intensity of IFN-γ ex-pression decreased, and there was little difference compared with the control group. Conclusions Renal damage can be induced by prolonged hyperoxia exposure. The intensity of IFN-γ expression increased in kidney, which contributed to the damage of kidney.