摘要
目的建立小鼠局部淋巴结检测结合耳肿胀程度评估的方法鉴别光敏物。方法受试物加UVA照射(剂量10J/cm2)连续3d在BALB/c小鼠耳背部进行激发,最后一次照射结束后24h切取引流的局部淋巴结,用淋巴细胞计数和MTT比色法测定淋巴细胞增殖率反映局部淋巴结的增殖情况;同时测量小鼠耳肿度以反映皮肤的刺激反应;用双抗体夹心ELISA法进一步测定局部淋巴结细胞72h培养上清液中干扰素-γ(IFN-γ),白介素-2(IL-2)以及白介素-4(IL-4)的含量。结果强光变应原四氯水杨酰苯胺引起局部淋巴结的增殖反应而不伴耳肿胀反应;弱光变应原6甲基香豆素既不引起局部淋巴结的增殖反应又不出现耳肿胀反应;光毒物质8-甲氧补骨脂素同时引起局部淋巴结增殖和耳肿胀反应。用四氯水杨酰苯胺预先致敏后再进行激发,局部淋巴结中IL-4的分泌量明显升高(P<0.05)。结论小鼠局部淋巴结检测结合耳肿胀程度评价的方法可较快鉴定较强的接触性光变应原和光毒物质,但对识别较弱的光变应原敏感性不足;预先致敏后激发阶段局部淋巴结中IL-4的分泌量明显升高是光变应原区别于光毒物质的突出特点。
Objective To establish a method of murine local lymph node assay (LLNA) combined with measurement of ear swelling for the identification of photosensitive agents. Methods The female BALB/c mice received test chemicals or vehicle alone on the back skin of both ears and then were exposed to UVA irradiation on three consecutive days. The post-auricular lymph nodes draining the ear tissue were excised 24 h following the last irradiation. Lymph node cell counts and lymphocyte proliferative rates were determined, which indicated lymph node hyperplasia. While ear swelling was also measured, to reveal skin irritating reactions. Some cytokines (IFN-γ, IL-2 and IL-4) released by the draining lymph node were also analyzed by ELISA. Results Tetrachlorosalicylanilide, a strong photoallergen, caused lymph node hyperplasia without ear swelling. The mild photoallergen (6-methylcoumarin) showed neither lymph node proliferation nor ear swelling reactions. But 8-methoxypsoralen, a phototoxic substance, induced both lymph node hyperplasia and ear swelling. The level of IL-4 was significantly increased when the mice were previously sensitized with tetrachlorosalicylanilide (P < 0.05). Conclusions LLNA combined with the measurement of ear swelling makes it possible to differentiate strong photoallergens from phototoxic substance, but is not sensitive enough to detect mild photoallergens. Cytokine analysis of the draining lymph node may provide an additional method for the differentiation of photoallergic agents from phototoxic substances.
出处
《中华皮肤科杂志》
CAS
CSCD
北大核心
2004年第10期566-568,共3页
Chinese Journal of Dermatology
