注射氨基酮戊酸光动力疗法对大鼠痤疮样炎性结节模型的疗效及组织病理学影响

【摘要】 目的 探讨注射氨基酮戊酸（ALA）光动力疗法对大鼠痤疮样炎性结节模型的疗效及组织病理改变。方法 40只SPF级SD大鼠分为正常对照组、模型对照组、注射ALA组、外敷ALA组,每组10只。除正常对照组不处理外,其余3组大鼠右耳廓内侧接种痤疮丙酸杆菌,建立大鼠痤疮样炎性结节模型。造模成功后,模型对照组不处理,注射ALA组将5%ALA注射入结节内再予红光照射,外敷ALA组直接外敷5%ALA于鼠耳痤疮样结节处再予红光照射,均为每周1次,共2次。末次治疗24 h后观察各组大鼠耳部大体表现和组织病理学变化,测量耳廓厚度,并检测肝肾功能。采用单因素方差分析和LSD-t检验比较各组差异。结果 正常对照组、模型对照组、外敷ALA组、注射ALA组大鼠耳廓厚度分别为（0.435 ± 0.006）、（1.269 ± 0.071）、（1.088 ± 0.098）、（0.699 ± 0.095） mm,差异有统计学意义（F = 235.60,P < 0.001）,模型对照组耳廓厚度高于正常对照组、外敷ALA组和注射ALA组（t 值分别为24.18、5.24、16.48,均P < 0.01）;注射ALA组低于外敷ALA组（t = 11.24,P < 0.01）。外敷ALA组和注射ALA组大鼠耳廓局部红肿程度、结节数均低于模型对照组,真皮及皮下组织浸润炎症细胞数量减少,注射ALA组结节消退更明显,亦未见团块状分布的炎症细胞或微脓肿形成。各组大鼠丙氨酸转氨酶、天冬氨酸转氨酶、肌酐、尿素氮水平差异均无统计学意义（均P > 0.05）。结论 注射ALA光动力疗法治疗大鼠痤疮样炎性结节模型较外敷ALA光动力疗法治疗更有效。

Photodynamic therapy with intralesional injection of aminolevulinic acid in a rat model of acneiform inflammatory nodules: evaluation of therapeutic efficacy and histopathological changes

【Abstract】 Objective To assess the therapeutic efficacy and histopathological effect of photodynamic therapy （PDT） with intralesional injection of aminolevulinic acid （ALA） in a rat model of acneiform inflammatory nodules. Methods Forty specific pathogen-free （SPF） SD rats were randomly and equally divided into normal control group, model control group, ALA injection group and topical ALA group. Rats in the normal control group received no treatment, and those in the other 3 groups were inoculated with Propionibacterium acne suspension on the right auricle for the establishment of a rat model of acneiform inflammatory nodules. After successful modeling, rats in the model control group received no other treatment, those in the ALA injection group were intranodularly injected with 5% ALA followed by red light irradiation, and those in the topical ALA group were topically treated with 5% ALA on the acneiform inflammatory nodules followed by red light irradiation. The treatment was performed once a week for 2 weeks. Twenty-four hours after the last treatment, general appearance and histopathological changes of rat ears were observed in each group, the thickness of rat auricles was measured, and liver and kidney functions were evaluated. Statistical analysis was carried out by using one-way analysis of variance and least significant difference-t test for comparisons among the groups. Results The thickness of rat auricles significantly differed among the normal control group, model control group, topical ALA group and ALA injection group （0.435 ± 0.006, 1.269 ± 0.071, 1.088 ± 0.098, 0.699 ± 0.095 mm, respectively, F = 235.60, P < 0.001）, and was significantly higher in the model control group than in the normal control group, topical ALA group and ALA injection group （t = 24.18, 5.24, 16.48 respectively, all P < 0.01）, but significantly lower in the ALA injection group than in the topical ALA group （t = 11.24, P < 0.01）. Compared with the model control group, the topical ALA group and ALA injection group showed decreased degree of local redness and swelling as well as number of nodules on the rat auricle, and decreased quantity of infiltrating inflammatory cells in the dermis and subcutaneous tissues. Compared with the topical ALA group, nodules regressed more markedly in the ALA injection group, and no clumps of inflammatory cells or microabscesses were observed in the ALA injection group. There was no significant difference in levels of alanine aminotransferase, aspartate aminotransferase, creatinine or urea nitrogen among the 4 groups （all P > 0.05）. Conclusion PDT with intralesional injection of ALA is more effective for the treatment of acneiform inflammatory nodules in rat models than PDT with topical application of ALA.