Abstract
Goldfish exposed to the cold (5 °C) for a week exhibited modifications in polyamines metabolism, as shown by the increase of putrescine levels in liver, heart, muscle and brain, whereas the content of spermidine and spermine was unchanged. Putrescine increases in tissues considered were concomitant with a remarkable rise in ornithine decarboxylase activity. Kinetic analysis of brain enzyme activity showed that the apparent K (m) was unchanged by cold exposure, whereas V (max) was strongly increased.