Disruption of the hypothalamo-pituitary-interrenal axis in 1+ yellow perch (Perca flavescens) chronically exposed to metals in the environment

Abstract

Although it has been reported that adult yellow perch (Perca flavescens) chronically exposed to metals in the environment exhibit endocrine impairment characterized by blunted cortisol secretion, little is known about the vulnerability of early life stages. Young-of-the-year (YOY) and 1+ yellow perch were captured, subjected to a standardized stress test or adrenocorticotropic-hormone stimulation in lakes situated along a contamination gradient of Cd, Cu, and Zn in the mining region of Abitibi, Quebec. For the first time, whole-body cortisol concentrations were measured. The 1+ fish with elevated whole-body Cd, Cu, and Zn concentrations had an impaired capacity to respond to an acute stress challenge. Although YOY perch had similar whole-body Cd concentrations to 1+ perch, no effects on physiological status were detected in relation to body burdens of metals. Metal contamination did not affect whole-body thyroid-hormone concentrations, condition factor, or hepatosomatic index in 1+ or YOY perch. These results indicate that effects of Cd, Cu, and Zn on the functional integrity of the hypothalamo-pituitary-interrenal axis in yellow perch are detectable after only 1 year of environmental exposure.