CATECHOLAMINE RELEASE AND INTERRENAL RESPONSE OF BROWN TROUT, SALMO-TRUTTA, EXPOSED TO ALUMINUM IN ACIDIC WATER

Cannulated brown trout, Salmo trutta, were exposed for 36 h to synthet ic water with a low calcium content of pH 5 and similar synthetic wate r dosed with aluminium to raise the filterable Al from 5 to 290 mu g l (-1) over the 36-h period. There were no significant disturbances of p lasma concentrations of glucose, cortisol or catecholamine (adrenaline and noradrenaline) in fish held in water of pH 5. The addition of alu minium to this acidic synthetic water resulted in a generalized endocr ine stress response with a four-fold increase in plasma glucose concen tration after 18 h and a significant increase in plasma cortisol conce ntration from 24 h onwards when filterable Al exceeded 200 mu g l(-1). Plasma catecholamine concentration indicated an adrenergic stress res ponse in aluminium-exposed brown trout. A transient doubling in noradr enaline after 6 h in Al was followed by a larger increase in both plas ma adrenaline and noradrenaline concentrations in fish surviving the 3 6-h exposure to Al.