Uptake of Cadmium in Perfused Rainbow Trout (Salmo gairdneri) Gills

Abstract

Uptake of cadmium in gills from rainbow trout (Salmo gairdneri) has been studied by the head perfusion technique. The importance of checking the viability of the perfused gills is considered and some viability criteria are discussed. The results show that cadmium is transferred through perfused gills. A 10-fold increase in the external Cd concentration from 5 × 10−8 to 5 × 10−7 mol∙L−1 resulted in a nearly 100-fold increase in cadmium transfer. At higher cadmium concentrations the uptake rate of the element diminished after having reached a maximum within 30 min. A complexing agent, EDNTA, which strongly chelates free cadmium ions decreases the transfer of cadmium through the gills. The advantage of using in vitro techniques instead of conventional uptake experiments is discussed and it is concluded that the gill perfusion technique is a useful tool in studies of factors affecting heavy metal uptake in fish.Key words: perfusion technique, fish gills, Salmo gairdneri, cadmium uptake, viability, EDNTA