Johnson L R, Davenport R, Balbach H, Schaeffer D J
Department of Veterinary Biosciences, University of Illinois, Urbana 61801.
Ecotoxicol Environ Saf. 1994 Feb;27(1):23-33. doi: 10.1006/eesa.1994.1004.
Coexposure of 2,4,6-trinitrotoluene (TNT), 2-amino-4,6-dinitrotoluene (2A), or 4-amino-2,6-dinitrotoluene (4A) to near-ultraviolet (nuv) light (lambda max-354 nm) significantly enhanced their toxicity toward Photobacterium phosphoreum (Microtox bioassay) during 30 min but not 15 min. Based on the slopes of the dose-response lines, the nuv coexposure and dark toxic mechanisms of action for TNT, 2A, and 4A appeared to be similar. nuv coexposure of binary mixtures significantly enhanced (supraadditivity) the toxicity of these compounds to P. phosphoreum. Under normal laboratory lighting, the toxicity of TNT + 2A and 2A + 4A mixtures were supraadditive but the toxicity of TNT + 4A mixtures could be explained by simple addition. Supporting these conclusions, the response curves of alpha-terthienyl, a compound known not to require nuv for toxicity, were similar in the dark and with nuv coexposure. In contrast, angelicin and psoralen, compounds known to require nuv coexposure to damage DNA, gave response curves having different slopes in the dark and with nuv coexposure. The nuv coexposure Microtox assay was able to detect and quantify phototoxicity in psoralen, angelicin, alpha-terthienyl, anthracene, TNT, and aminodinitrotoluenes.
2,4,6-三硝基甲苯（TNT）、2-氨基-4,6-二硝基甲苯（2A）或4-氨基-2,6-二硝基甲苯（4A）与近紫外（nuv）光（最大波长-354nm）共同暴露30分钟时，会显著增强它们对费氏弧菌的毒性（微毒性生物测定），但15分钟时则不会。根据剂量-反应线的斜率，TNT、2A和4A的nuv共同暴露和黑暗中的毒性作用机制似乎相似。二元混合物的nuv共同暴露显著增强（超加和性）了这些化合物对费氏弧菌的毒性。在正常实验室光照下，TNT + 2A和2A + 4A混合物的毒性具有超加和性，但TNT + 4A混合物的毒性可用简单相加来解释。支持这些结论的是，已知对毒性不需要nuv的化合物α-三联噻吩，在黑暗中和与nuv共同暴露时的反应曲线相似。相比之下，已知需要nuv共同暴露才能损伤DNA的化合物当归素和补骨脂素，在黑暗中和与nuv共同暴露时的反应曲线斜率不同。nuv共同暴露微毒性测定能够检测和量化补骨脂素、当归素、α-三联噻吩、蒽、TNT和氨基二硝基甲苯中的光毒性。
