Effects of 3,3′,4,4′-tetrachlorobiphenyl on the dynamics of vitamin A in brook trout (Salvelinus fontinalis) and intestinal retinoid concentrations in lake sturgeon (Acipenser fulvescens)

Abstract

A single i.p. injection of 5 μg 3,3′,4,4′-tetrachlorobiphenyl (TCBP)/g body mass in adult brook trout (Salvelinus fontinalis) resulted in decreased (p < 0.0001) growth rate despite pair feeding. Plasma retinol decreased (p < 0.0037). Intestinal retinyl palmitate (RP) and 3,4-dehydroretinyl palmitate (DRP) concentrations decreased in TCBP-injected males (RP, p < 0.0143; DRP, p < 0.0009), whereas retinoid levels did not decrease significantly in TCBP-injected females. The RP:DRP ratio in trout liver increased (p < 0.0001). These results suggested that DRP is more sensitive than RP to the effects of TCBP. No significant differences in ovarian retinoids occurred in post-spawning trout. Field validation of the effects on intestinal retinoids was conducted with lake sturgeon (Acipenser fulvescens) caught at a contaminated site on the Des Prairies River near Montréal (St. Lawrence River population) and reference sturgeon taken from a site near the origin of the Ottawa River in LaVerendrye Park. Intestinal retinoid concentrations were lower (RP, p < 0.0008; DRP, p < 0.0004) in the St. Lawrence River sturgeon. Our results demonstrate that a coplanar PCB is capable of altering vitamin A dynamics in several tissues and organs, and may cause a lowering of retinoids in the intestine.