Serum enzymes in rainbow trout as tools in the diagnosis of water quality.

Abstract

The activities of serum enzymes are likely to reflect the metabolic state of fish in much the same way as they do in mammals. Thus it can be expected that toxic agents or factors which lead to chronic impairment of the animals' metabolism will cause changes, usually increases, of the activities of some serum enzymes. Many studies have been conducted in which fish were experimentally stressed and the ensuing changes in serum enzyme activities recorded. Some of these responses are likely to be of a more general nature, i.e., indicating the organism's answer to a situation of stress brought about by a general deterioration of water quality. We have tested this idea further by measuring the activities of two transaminases, glutamic oxalacetate transaminase (GOT, E.C.2.6.1.1.) and glutamic pyruvate transaminase (GPT, E.C.2.6.1.8.) in the serum (S) of rainbow trout (Salmo gairdneri) caught at various distances from the outflow of a sewage plant into the river Inn near Innsbruck. The quality of the river water was also tested by measuring, at the points where the fish were caught, the concentration of NH/sub 3/, NO/sub 3/ and NO/sub 2/.