In vivo and in vitro effects of temperature on monoamine oxidase activity in brain and other tissues of the goldfish. Carassius auratus L.
1. The maximum velocity (Vmax) and apparent Michaelis constant (Km) of brain and liver monoamine oxidase (MAO) in goldfish were different in fish acclimated to 22 degrees C and to 7 degrees C ambient temperature. 2. In brain, Vmax and Km were dependent upon incubation temperature, but both parameters were lower in 7 degrees C, adapted fish over most of the incubation temperature range. 3. The values obtained for Km showed a plateau at incubation temperatures at and below 25 degrees C for warm water fish, and at and below 20 degrees C for cold water fish. The activation energy of brain MAO was lower in fish adapted to the colder water. 4. These results show that goldfish MAO displays changes in functional activity in response to a change in environmental temperature. Apparently the purpose of this adaptation is to compensate for a reduction in enzyme concentration.
D000818:Animals; D001921:Brain / Q000201:enzymology*; D003530:Cyprinidae / Q000378:metabolism*; D006054:Goldfish / Q000378:metabolism*; D066298:In Vitro Techniques; D007700:Kinetics; D008995:Monoamine Oxidase / Q000378:metabolism*; D012737:Sex Factors; D013696:Temperature
D008995:Monoamine Oxidase