Age-related responses in rats to concentrated urban air particles (CAPs)
Age-related responses in rats to concentrated urban air particles (CAPs)
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DOI：
10.1080/0895-8378.1987.11463183
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发表时间：
2000-01-01
影响因子：
2.1
通讯作者：
Godleski, JJ
中科院分区：
文献类型：
--
作者：
Clarke, RW;Catalano, P;Godleski, JJ
流行病学研究报告称，老年人在暴露于高水平的环境颗粒物后，有更高的有害反应风险。为了在毒理学模型中研究这一发现，将老年Fisher大鼠暴露于来自波士顿的浓缩城市空气颗粒物（CAP）3天。检验的假设是，与年轻的正常动物相比，老年动物在接触CAPs后会表现出更严重的肺部炎症和血液学变化。暴露前，将老年Fisher大鼠（> 77月龄）和幼年Fisher大鼠（4-6周）在无病毒抗原设施中饲养3月。在此期间之后，将老年和年轻大鼠暴露于CAP或假暴露于过滤空气，每天5小时，连续3天（10只大鼠/组x 4组共= 40只大鼠）。每日综合CAP浓度分别为80，170和50 μ g/m3，在第1，2和3天。在整个暴露期间，无动物死亡。暴露最后一天后20小时，通过心脏穿刺采集血液，并进行支气管肺泡灌洗（BAL）。年轻大鼠的总BAL细胞计数显著高于老年大鼠，以及与假手术相比，CAP暴露后BAL多形核白细胞（PMN）显著增加。与假手术组相比，老年大鼠暴露于CAP后BAL PMN也表现出小但显著的增加。在总BAL细胞计数、BAL乳酸脱氢酶、总白色血细胞（WBC）计数或WBC PMN、淋巴细胞和单核细胞百分比方面，老年动物中无CAP相关显著变化。当比较老年与年轻（CAP或过滤空气暴露）动物时，高龄与总BAL细胞计数、总WBC计数、血液淋巴细胞百分比和血液血红蛋白的显著减少相关，还观察到血液PMN百分比的显著增加。上述结果表明：（1）年轻的fisher大鼠可能是检查CAP暴露后肺部炎症反应的敏感模型，（2）尽管存在较高百分比的循环中性粒细胞，但老年大鼠中缺乏肺部炎症反应可能反映了对吸入颗粒的敏感性降低。
Epidemiological studies have reported that elderly individuals have a higher risk of detrimental responses following exposure to elevated levels of ambient particulate matter. To investigate this finding in a toxicological model, aged Fisher rats were exposed for 3 days to concentrated urban air particles (CAPs) from Boston. The hypothesis tested was that older animals would exhibit more severe pulmonary inflammation and hematological changes following the CAPs exposure when compared to young normal animals. Aged Fisher rats (> 77 mo) and juvenile Fisher rats (4-6 wk) were maintained in a virus-antigen free facility for 3 mo prior to exposure. Following this period, aged and young rats were exposed to CAPs or sham-exposed to filtered air for 5 h/day for 3 consecutive days (10 rats/group x 4 groups total = 40 rats). Daily integrated CAPs concentrations were 80, 170, and 50 mu g/m(3) on day 1, 2, and 3, respectively. None of the animals died throughout the duration of exposure. Twenty-Tour hours following the last day of exposure, blood was collected by cardiac puncture, and bronchoalveolar lavage (BAL) was performed. Young rats had significantly higher total BAL cell counts compared to old rats, as weil as a significant increase in BAL polymorphonuclear leukocytes (PMN) following CAPs exposure compared to sham. Old rats also exhibited a small, but significant increase in BAL PMN following exposure to CAPs compared to sham. There were no CAPs-related significant changes in aged animals in total BAL cell counts, BAL lactate dehydrogenase, total white blood cell (WBC) counts, or the percent of WBC PMN, lymphocytes, and monocytes. When comparing aged versus young (CAPs- or filtered air-exposed) animals, advanced age was associated with significant decrements in the total BAL cell counts, total WBC counts, percent or blood lymphocytes, and blood hemoglobin, a significant increase in the percent of blood PMN was also observed. The above results suggest: (1) Young fisher rats may represent a sensitive model for the examination of pulmonary inflammatory responses following CAPs exposure, and (2) the lack of a pulmonary inflammatory response in the aged rats, despite the presence of a higher percentage of circulating neutrophils, may reflect decreased sensitivity to inhaled particles.