Koivusaari U
J Exp Zool. 1983 Jul;227(1):35-42. doi: 10.1002/jez.1402270106.
The thermal acclimatization of hepatic cytochrome P-450-dependent polysubstrate monooxygenase (PSMO) and UDP-glucuronosyltransferase of mature rainbow trout (Salmo gairdneri) was studied. The results indicate that the PSMO system, 7-ethoxycoumarin and benzo(a)pyrene as substrates, shows almost ideal acclimatization pattern in autumn during water cooling. The enzyme activities were identical if measurements were carried out at acclimatization (=environmental) temperatures which were 20 degrees C in August and 5 degrees C in November. If a constant incubation temperature (18 degrees C) was used, the PSMO activities were significantly higher in cold (5 degrees C)-acclimatized fish. The acclimatization process could be seen both in specific and total activities. The content of cytochrome P-450 remains at constant level from August to November. In early summer during water warming the PSMO activities increased considerably in both sexes in all incubation conditions. The specific and total UDP-glucuronosyltransferase activities were significantly higher in warm-acclimatized fish both in the autumn and in the spring if the activities were measured at environmental temperature. No differences could be detected if the measurements were carried out at constant experimental temperature (18 degrees C).
对成熟虹鳟（鲑鱼）肝脏中细胞色素P - 450依赖的多底物单加氧酶（PSMO）和UDP - 葡萄糖醛酸基转移酶的热适应性进行了研究。结果表明，以7 - 乙氧基香豆素和苯并(a)芘为底物的PSMO系统在秋季水冷期间呈现出几乎理想的适应性模式。如果在适应（即环境）温度下进行测量，酶活性是相同的，8月的适应温度为20℃，1月为5℃。如果使用恒定的孵育温度（18℃），冷适应（5℃）的鱼的PSMO活性显著更高。在比活性和总活性中都可以看到适应过程。从8月到11月，细胞色素P - 450的含量保持在恒定水平。在初夏水温升高期间，在所有孵育条件下，两性的PSMO活性都显著增加。如果在环境温度下测量活性，暖适应的鱼的比活性和总UDP - 葡萄糖醛酸基转移酶活性在秋季和春季都显著更高。如果在恒定的实验温度（18℃）下进行测量，则未检测到差异。
