Effect of urea and low temperature on the expression and activity of flavin-containing monooxygenase in the liver and gill of rainbow trout (Oncorhynchus mykiss)

摘要: Little is known about the physiological role of flavin containing monooxygenases (FMOs) in teleost fish. Recent studies have indicated induction during saltwater adaptation several telost species including rainbow trout. A product FMOs, trimethylamine N-oxide (TMAO) and urea also been shown to increase trout muscle adapatation. TMAO counteracts denaturing effects urea. In order evaluate as a possible inducer FMO expression activity, adult were infused for 48 h with urea/saline solutions at loading rate 8 mmol urea/kg/day. To determine whether low temperature had any effect on one group animals was exposed (2–3 °C) h. Gill FMO-catalyzed thiourea oxygenase activity significantly induced by temperature, twice observed (1.116±0.356 nmol/min/mg) compared infusion 10 °C (0.585±0.282 nmol/min/mg). Low without treatment caused 50% gill activity. liver, an liver (from 0.144±0.053 nmol/min/mg 0.464±0.237 nmol/min/mg), but unaffected co-exposure (0.523±219 correlated elevated tissue levels, concentrations not related. The interactions between urea, tissue-specific FMOs indicate may contribute other cellular processes besides osmoregulation.