Influence d'une augmentation de la température sur certains aspects du catabolisme azoté chez la truite arc-en-ciel (Salmo gairdneri Rich.)

Abstract

The daily mean rates of blood ammonia and urea did not differ significantly at 9 and 17 °C. However, the pattern of these two parameters during the circadian cycle was not the same at 9 °C as after 23 days at 17 °C. The enzymatic activities rose after one day at 17 °C and remained unchanged, except for arginase which showed perfect thermal compensation.During the circadian cycle, there was some similitude between glutaminase activity and blood ammonia at 9 °C and after 23 days at 17 °C, as well as between arginase activity and blood urea.

Effect of simultaneous variation of weight, density, temperature and O2 concentration on rainbow trout (Oncorhynchus mykiss) body composition

“…nificantly influenced by water temperature (9-18 °C) in rainbow trout (Cho and Kaushik, 1990 (Creach et al, 1981(Creach et al, -1982Vellas et at, 1982;Zanuy and Carrillo, 1985). This fact requires a reduction in feeding level.…”

Environmental effects on feed utilization

“…Specific activities of both aspartate and alanine (EC 2.6.1.2) aminotransferases decreased when carp at natural temperatures of 7,15 and 20°C underwent a rapid rise of 8°C; when carp at summer water temperature of 25°C was acclimated to 33°C, the specific activities increased. Of the several enzymes involved in ammonio-and ureogenesis in trout, only arginase (EC 3.5.3.1) showed perfect thermal compensation to a rise in temperature (Vellas et al 1982). Other enzymes like glutamate dehydrogenase (EC 1.4.1.3), glutaminase (EC 3.5.1.2) and uricase (EC 1.7.3.3) showed an increase in activity immediately after transfer and remained unchanged.…”