Picada Jaqueline N, Maris Angel F, Ckless Karina, Salvador Mirian, Khromov-Borisov Nikita N, Henriques João Antonio Pêgas
Centro de Biotecnologia e Departamento de Biofísica, Universidade Federal do Rio Grande do Sul, UFRGS, Av Bento Gonçalves 9500, Prédio 43421, Campus do Vale, Caixa Postal 15005, CEP 91501-970, Porto Alegre, RS, Brazil.
Mutat Res. 2003 Aug 5;539(1-2):29-41. doi: 10.1016/s1383-5718(03)00132-3.
Apomorphine (APO) is considered to be a classical mixed type dopamine D(1) and D(2) receptor agonist. It has been used in the therapy of Parkinson's disease and, more recently, for the treatment of erectile dysfunction. Like other catechols (e.g. dopamine), APO easily autoxidizes, producing quinone and semiquinone derivatives that may lead to the formation of reactive oxygen species and induce neurotoxicity. We assayed mutagenicity, antimutagenicity, and cytotoxicity of these compounds by means of the Salmonella/microsome assay, WP2 Mutoxitest and sensitivity assay in Saccharomyces cerevisiae yeast strains lacking antioxidant defenses. In the absence of S9 mix both compounds Apomorphine and its oxidation derivative, 8-oxo-apomorphine-semiquinone (8-OASQ), both at doses ranging from 20 to 80 microg per plate, induced frameshift mutations in TA98 and TA97 S. typhimurium strains, with 8-OASQ being up to two times more mutagenic. However, for strains which detect oxidative mutagens, 8-OASQ acted as a mutagen while APO was an antimutagen, inhibiting H(2)O(2) and t-BOOH-induced mutagenicity in TA102 S. typhimurium and WP2-derived E. coli strains. The S9 mix inhibited all mutagenic effects, probably either by conjugation of APO and 8-OASQ to proteins or by quenching reactive oxygen species. In sensitivity assays with S. cerevisiae, APO was only clearly cytotoxic to some strains at higher doses (200 and 400 microg/ml), whereas 8-OASQ dose-dependently sensitized all the strains, mainly the mutants lacking catalase (deltactt1), superoxide dismutase (deltasod1) and Yap1 transcription factor (deltayap1), suggesting that 8-OASQ cytotoxicity towards S. cerevisiae results from its pro-oxidant properties. APO also tended to protect S. cerevisiae strains against oxidative damage induced by high concentrations of H(2)O(2) and t-BOOH, while 8-OASQ enhanced pro-oxidant effects and induced adaptation responses to these agents. These results suggest that the 8-OASQ oxidation product of APO might induce cytotoxic and genotoxic effects.
阿扑吗啡（APO）被认为是一种经典的多巴胺D(1)和D(2)受体混合型激动剂。它已被用于帕金森病的治疗，最近也用于治疗勃起功能障碍。与其他儿茶酚（如多巴胺）一样，APO容易自动氧化，产生醌和半醌衍生物，这些衍生物可能导致活性氧的形成并诱导神经毒性。我们通过沙门氏菌/微粒体试验、WP2 Mutoxitest以及在缺乏抗氧化防御的酿酒酵母菌株中的敏感性试验，检测了这些化合物的诱变性、抗诱变性和细胞毒性。在没有S9混合物的情况下，阿扑吗啡及其氧化衍生物8-氧代-阿扑吗啡-半醌（8-OASQ），在每平板20至80微克的剂量范围内，均能在鼠伤寒沙门氏菌TA98和TA97菌株中诱导移码突变，其中8-OASQ的诱变性高达两倍。然而，对于检测氧化诱变剂的菌株，8-OASQ起诱变作用，而APO是抗诱变剂，可抑制鼠伤寒沙门氏菌TA102和WP2衍生的大肠杆菌菌株中H(2)O(2)和叔丁基过氧化氢诱导的诱变性。S9混合物抑制了所有的诱变作用，可能是通过将APO和8-OASQ与蛋白质结合，或者通过淬灭活性氧来实现的。在酿酒酵母的敏感性试验中，APO仅在较高剂量（200和400微克/毫升）时对某些菌株有明显的细胞毒性，而8-OASQ则剂量依赖性地使所有菌株敏感，主要是缺乏过氧化氢酶（deltactt1）、超氧化物歧化酶（deltasod1）和Yap1转录因子（deltayap1）的突变体，这表明8-OASQ对酿酒酵母的细胞毒性源于其促氧化特性。APO也倾向于保护酿酒酵母菌株免受高浓度H(2)O(2)和叔丁基过氧化氢诱导的氧化损伤，而8-OASQ则增强了促氧化作用并诱导了对这些试剂的适应性反应。这些结果表明，APO的8-OASQ氧化产物可能诱导细胞毒性和遗传毒性作用。
