Responsiveness of the interrenal tissue of yellow perch (Perca flavescens) from contaminated sites to an ACTH challenge test in vivo

Abstract

The effects of chronic toxic stress on the hypothalamo-pituitary-interrenal (HPI) axis were investigated in yellow perch (Perca flavescens) captured at a reference site (Lake Memphremagog) and two sites contaminated with heavy metals and organic contaminants (Ile Perrot and Iles de la Paix, Lake St. Louis) in spring, summer, and fall. Cortisol secretion of the fish was stimulated in situ by an acute capture stress or by an i.p. injection of 4 IU/100 g body mass of porcine corticotropin (ACTH1-39). The response to both these challenges was lower in perch from the highly contaminated site than in perch from the reference site in the spring but not in summer. In fall, fish from the highly contaminated site had, as in spring, a lower response to ACTH than fish from the reference site. The reduced ability of perch to respond to capture stress or to ACTH indicates that the interrenal tissue in fish from contaminated sites is functionally impaired. Cortisol-impaired fish also had abnormal carbohydrate metabolism. The reduced ability of wild fish from contaminated sites to respond to a standardized ACTH challenge may be used as an early indicator of contamination-induced chronic stress.

Stress-induced regulation of steroidogenic acute regulatory protein expression in head kidney of Gilthead seabream (Sparus aurata)

“…ACTH stimulated the StAR gene expression in the seabream head kidney preparations by binding to its specific membrane receptors, as demonstrated when 1 mM CIP, an antagonist of the ACTH receptor (Li et al 1978), effectively blocked the ACTHstimulated StAR expression in our in vitro model, without affecting the basal levels of StAR expression. The rapid increase in cortisol levels, which we observed after ACTH treatment, is in agreement with several previous studies conducted under various experimental conditions (Donaldson 1981, Nichols & Weisbart 1984, Girard et al 1998, Pottinger & Carrick 2001, Hagen et al 2006. It also agrees with the previous data found in the same species, S. aurata, in our laboratory (Rotllant et al 2001, Ganga et al 2006 showing that ACTH caused a rapid increase in cortisol levels in superfused head kidney tissue.…”

Attenuated Carbohydrate and Gill Na+ , K+-ATPase Stress Responses in Whitefish Caged near Bleached Kraft Mill Discharges

“…Lifelong exposure of brown trout (Salmo trutta) to waterborne Cd and Zn (Norris et al, 1999) and 5-day dietary exposure of tilapia (Oreochromis mossambicus) to PCB (Quabius et al, 1997) have been found to result in a delayed cortisol response to acute disturbance by con"nement. In the present study, however, the level of plasma cortisol reached was not observed to be decreased (Quabius et al, 1997;Girard et al, 1998;Norris et al, 1999;Lappivaara, 2000) by the prevailing exposure to BKMEs. This contrasts with some other "eld studies (Hontela et al, 1992(Hontela et al, , 1995(Hontela et al, , 1997, in which the time-dependent progression of cortisol response has not, however, been elucidated by a serial data grouping.…”

Bioenergetic costs of heavy metal exposure in yellow perch (Perca flavescens): in situ estimates with a radiotracer (137Cs) technique

“…Lake Memphremagog, located in the Eastern Townships (approximately 125 km east of Montreal) and remote from any industrial activity (Girard et al 1998), was sampled and included in the set of reference lakes. Lake St. Louis, a fluvial lake in the St. Lawrence River immediately west of the island of Montreal, receives pollutant loading from multiple sources (Hontela et al 1992).…”