Metal redistribution in largemouth bass (Micropterus salmoides) in response to restrainment stress and dietary cadmium: role of metallothionein and other metal-binding proteins.

1. Fish stressed by restrainment displayed elevated serum cortisol, copper and zinc levels; dietary cadmium had no effect. 2. Stress/dietary cadmium increased liver copper levels in a metal pool containing metallothionein and non-metallothionein proteins but decreased intestinal zinc bound as low molecular weight forms. 3. After restrainment, zinc losses occurred in dorsal skeletal muscle, ovary and spleen: copper decreased in intestine and pyloric caecum. 4. Dietary cadmium altered intestinal zinc distribution and raised hepatic Cu-binding protein levels but did not alter plasma zinc, copper or cortisol levels. 5. Alterations in zinc and copper concentrations during stress contrast with mammalian models.