Cibulas W, Brooks S M, Murlas C G, Miller M L, McKay R T
Department of Medicine, University of Cincinnati School of Medicine, Ohio 45267.
J Appl Physiol (1985). 1988 May;64(5):1773-8. doi: 10.1152/jappl.1988.64.5.1773.
The influence of cyclophosphamide-induced granulocyte depletion on toluene diisocyanate (TDI)-related changes in airway reactivity and pathology was assessed in guinea pigs. Twelve cyclophosphamide-treated and 12 control animals comprising each group were studied physiologically before and 2 h after a single 10-min exposure to 3 ppm of TDI. Reactivity was determined in intact unanesthetized animals by measuring specific airway conductance before and during intravenous acetylcholine infusion. After testing, tracheal tissue for light microscopic examination was obtained from three hyperreactive guinea pigs in each exposed group and compared with tissue from treated and control animals (n = 3 each) that had not been TDI exposed. Cyclophosphamide treatment caused substantial decreases in both circulating and airway granulocyte counts. However, the incidence and degree of bronchial hyperreactivity that occurred 2 h post-TDI was similar in the untreated and treated groups. Our results indicate that TDI-induced bronchial hyperreactivity 1) occurs shortly after a brief high concentration exposure and 2) appears independent of circulating or airway granulocyte counts.
在豚鼠中评估了环磷酰胺诱导的粒细胞减少对甲苯二异氰酸酯（TDI）相关气道反应性和病理学变化的影响。每组12只经环磷酰胺处理的动物和12只对照动物在单次10分钟暴露于3 ppm TDI之前和之后2小时进行了生理学研究。通过在静脉注射乙酰胆碱前后测量特定气道传导率，在完整未麻醉的动物中测定反应性。测试后，从每个暴露组的三只高反应性豚鼠中获取气管组织用于光镜检查，并与未暴露于TDI的处理组和对照组动物（每组n = 3）的组织进行比较。环磷酰胺治疗导致循环和气道粒细胞计数大幅下降。然而，TDI暴露后2小时出现的支气管高反应性的发生率和程度在未治疗组和治疗组中相似。我们的结果表明，TDI诱导的支气管高反应性1）在短暂高浓度暴露后不久发生，2）似乎与循环或气道粒细胞计数无关。
