Eh. Jorgensen et al., Influence of nutritional status on biomarker responses to PCB in the Arctic charr (Salvelinus alpinus), AQUAT TOX, 44(4), 1999, pp. 233-244
Transport of pollutants from industrial areas has resulted in Arctic enviro
nments facing increasing levels of organic pollution. Thus, a need for sens
itive and reliable biomarkers that can be used to assess the risk associate
d with exposure to xenobiotics in these areas has arisen. In high latitudes
, temporal variations in the nutritional status of animals can be considera
ble, and these variations may influence toxicokinetic processes and biomark
er responses. In the present study, different biomarker (cytochrome P450 (C
YP1A), pre- and post-stress plasma cortisol concentrations and fin erosion)
responses were recorded in groups of PCB-exposed (given a single oral dosa
ge of 1 mu g Aroclor 1260 (g body weight)(-1)) and unexposed Arctic charr.
Following treatment (PCB administration), fish were held for 141 days under
either a restricted feeding regime or without food. PCB exposure did not e
ffect either growth or organ lipid concentrations. Food deprivation resulte
d in a marked reduction in lipid concentration in muscle and kidney, and a
3- and 11-fold increase in the PCB concentrations in the kidney and liver o
f the PCB-exposed fish. Food deprivation did not appear to influence hepati
c EROD activities and CYP1A content, but the elevated PCB concentration in
the liver of the fasted, PCB-exposed fish seemed to result in a dose-relate
d increase in EROD activity and CYP1A content. Plasma cortisol concentratio
ns of unstressed fish were below the detection limit of 3.6 ng ml(-1) Post-
stress plasma cortisol concentrations were low in the food deprived fish, i
rrespective of PCB exposure. The highest post-stress plasma cortisol concen
trations were recorded in PCB-exposed, fed fish. The fish that were held wi
thout food had the lowest incidence of fin erosion, whereas the combination
of food deprivation and PCB exposure resulted in the highest prevalence of
fin erosion. Thus, nutritional status (i.e. long term food deprivation) in
fluenced both tissue concentrations of PCB, and biomarker responses. This m
ust be borne in mind if biomarkers are to be used in environmental monitori
ng programmes. (C) 1999 Elsevier Science B.V. All rights reserved.