Cornacoff J B, House R V, Dean J H
Department of Cellular and Molecular Toxicology, Chemical Industry Institute of Toxicology, Research Triangle Park, North Carolina 27709.
Fundam Appl Toxicol. 1988 Jan;10(1):40-4. doi: 10.1016/0272-0590(88)90249-7.
A radioisotopic incorporation assay utilizing [125I]iododeoxyuridine was compared to the standard mouse ear swelling test (MEST) for the strong sensitizers dinitrofluorobenzene and oxazolone, and for the three weak sensitizers ethylenediamine (EDA), glutaraldehyde, and nickel sulfate. Mice were sensitized epicutaneously on the abdomen for 4 consecutive days prior to challenging the left ear with the test agent and the right ear with the vehicle. A comparison of the mean difference between the test and the control ears showed that measuring reactivity 48 hr postchallenge on Day 7 is the most sensitive time period in the radioisotopic incorporation method. Both the isotopic and MEST assays gave positive results with the potent sensitizers, although the response detected by isotopic labeling of emigrating cells was up to 1000-fold greater than that determined by ear swelling measurements. No response was detected to the moderate to weak sensitizer EDA in either assay. Reactivity to glutaraldehyde was not detected by the radioisotopic assay but was minimally responsive and significant by the MEST. The opposite was true for nickel sulfate where minimal but significant reactivity was seen in the isotopic assay but not in the MEST. Although the radioisotopic assay had the advantages of being more quantitative and of having improved sensitivity, it was of no greater value than the MEST for detecting weak sensitizers. It was concluded that the mouse was not a suitable model for routinely detecting reactivity to weak sensitizers regardless of which of the two assays were used.
利用[125I]碘脱氧尿苷的放射性同位素掺入试验，与标准的小鼠耳部肿胀试验（MEST）进行了比较，以检测强致敏剂二硝基氟苯和恶唑酮，以及三种弱致敏剂乙二胺（EDA）、戊二醛和硫酸镍。在分别用受试剂刺激左耳和用赋形剂刺激右耳之前，小鼠在腹部进行连续4天的表皮致敏。对受试耳和对照耳之间平均差异的比较表明，在放射性同位素掺入法中，在第7天激发后48小时测量反应性是最敏感的时间段。对于强致敏剂，同位素试验和MEST试验均给出了阳性结果，尽管通过迁移细胞的同位素标记检测到的反应比通过耳部肿胀测量确定的反应大1000倍。在两种试验中均未检测到对中度至弱致敏剂EDA的反应。放射性同位素试验未检测到对戊二醛的反应性，但MEST试验有最小反应且显著。硫酸镍的情况则相反，在同位素试验中观察到最小但显著的反应性，而在MEST试验中未观察到。尽管放射性同位素试验具有更定量和灵敏度更高的优点，但在检测弱致敏剂方面，它并不比MEST更有价值。得出的结论是，无论使用两种试验中的哪一种，小鼠都不是常规检测对弱致敏剂反应性的合适模型。
