急性铬化物暴露肺损伤的剂量效应与时间过程

Dose-effect and time-course of lung injury in acute exposure to chromium compound

经一次气管灌注不同剂量可溶性六价铬酸钠（Ｎａ２ＣｒＯ４）后第２天和一次灌注０．９８ｍｇ·ｋｇ－１Ｎａ２ＣｒＯ４后不同时间，观察了ＳＤ大鼠支气管肺泡灌洗液（ＢＡＬＦ）和血液生化改变的剂量效应与时间过程。结果表明，Ｎａ２ＣｒＯ４的无效应剂量与阈剂量分别为０．００８和０．０４ｍｇ·ｋｇ－１，染毒剂量≥０．２０ｍｇ·ｋｇ－１时，ＢＡＬＦ中绝大多数生化参数呈现显著的剂量依赖性增加；严重中毒剂量（≥０．９８ｍｇ·ｋｇ－１）可引起ＢＡＬＦ和血液中几乎所有测试参数的显著增加，这种现象约持续一周，至少需要４周才能恢复正常。分析本次研究结果，可得出以下结论：≥０．９８ｍｇ·ｋｇ－１的Ｎａ２ＣｒＯ４可导致包括肺内细胞损伤、弥漫性肺泡炎和肺水肿在内的急性肺损伤；Ｎ－乙酰－β－Ｄ－氨基葡糖苷酶（ＮＡＧ）、溶菌酶（ＬＹＳ）、碱性磷酸酶（ＡＬＰ）、白蛋白（ＡＬｂ）和血管紧张素转换酶（ＡＣＥ），可能是评价接触较低剂量Ｎａ２ＣｒＯ４（＜０．

The dose-effect and the time-course of biochemical changes in bronchoalveolar lavage fluids(BALF)and serum from Sprague-Dawley rats were observed at d 2 after exposure to various Na2CrO4 doses and at the different time after exposure to 0.98mg·kg-1 Na2CrO4 by a single intratracheal instillation respectively,It was found that ineffective dose and threshold dose of Na2CrO4 were 0.008 and 0.04mg·kg-1.The majority of bioche-mical parameters in the BALF showed the does-dependent and significant increases at doses of ≥0.20mg·kg-1.The severe intoxication doses≥0.98mg·kg-1 Na2CrO4 could produce significantly increases of nearly all parameter values, which would last about one week and need at least four weeks to restore to the normal status,By analyzing the present results we conclude that ≥0.98mg·kg-1Na2CrO4can result in acute lung injury including pulmonary cyto-biomembrane damage,diffuse alveolitis and edeme,and that N-acetyl-β-Dglucosaminidase(NAG),lysozyme(LYS),alkaline phosphatase(ALP), albumin(ALb)and angiotensin-converting enzyme(ACE)are probably the most valuable and early sensitive indicators for evaluating the injury after exposure to the lower dose of Na2CrO4(<0.98mg·kg-1).