Iannelli M A, Marcucci I, Vittozzi L
Biochemical Toxicology Unit, Istituto Superiore di Sanità, Rome, Italy.
Ecotoxicol Environ Saf. 1994 Jul;28(2):172-80. doi: 10.1006/eesa.1994.1043.
UDPG-glucuronyltransferase (GT) activities have been determined in the hepatic microsomes of fish species recommended by OECD for some (eco)toxicological tests. Due to the heterogeneity of this enzyme family, different chemicals were used as substrate: 4-nitrophenol (4NP), 4 methylumbelliferone (4MU), and 2- and 4-hydroxybiphenyl (2OHB and 4OHB). The 4NP-GT and 2OHB-GT activities of hepatic microsomes from all the species were linearly dependent on the substrate concentration (tested concentrations up to 2 and 0.5 mM, respectively). 4OHB-GT and 4MU-GT demonstrated different degrees of saturation in the range of substrate concentrations 0-0.5 mM and 0-0.3 mM, respectively. Specific activities ranged among the species usually within a factor of about 3. The highest ratios (up to 10) were occasionally found for 4MU-GT (between trout and golden orfe) and 2OHB-GT (between guppy and carp, zebra fish, or trout). These results confirm that GT activities in fish are much lower than in mammals.
已测定经合组织推荐用于某些（生态）毒理学试验的鱼类肝脏微粒体中的尿苷二磷酸葡萄糖醛酸基转移酶（GT）活性。由于该酶家族的异质性，使用了不同的化学物质作为底物：4-硝基苯酚（4NP）、4-甲基伞形酮（4MU）以及2-和4-羟基联苯（2OHB和4OHB）。所有物种肝脏微粒体的4NP-GT和2OHB-GT活性均与底物浓度呈线性相关（测试浓度分别高达2 mM和0.5 mM）。4OHB-GT和4MU-GT在底物浓度范围分别为0 - 0.5 mM和0 - 0.3 mM时表现出不同程度的饱和。各物种的比活性通常相差约3倍。4MU-GT（在鳟鱼和金欧鳊之间）以及2OHB-GT（在孔雀鱼和鲤鱼、斑马鱼或鳟鱼之间）偶尔会出现高达10倍的最高比值。这些结果证实鱼类中的GT活性远低于哺乳动物。
