Uptake and Distribution of Three PCB Congeners and Endosulfan by Developing White Leghorn Chicken Embryos (Gallus domesticus)

Abstract

The distributions of PCB 105, 156, 189, and endosulfan in incubating, maternally exposed, viable white leghorn chicken eggs (Gallus domesticus) were investigated. Hens were subcutaneously injected every 4 days with a mixture of the above chemicals. One group of five eggs was removed from the incubator at each of 9, 14, and 19 days of incubation; dissected into three compartments (embryo, chorioallantoic membrane, and yolk + albumin); weighed; frozen; and then later analyzed for the dosing chemicals. Through 19 days of development (90% of incubation), greater than 70% of the total chemical mass in the whole egg remained within the yolk + albumin, whereas, depending on the chemical, 17% to 30% was absorbed by the embryo and 0.2% to 9% was transported into the chorioallantoic membrane. As a percentage of total PCB mass within the respective compartment, PCB 105 composition in the embryo and chorioallantoic membrane decreased significantly throughout development while PCB 156 and 189 composition increased significantly throughout development. Though endosulfan composition within any of the compartments was highly variable, it did not change significantly during development. The results of this study indicate that the majority of avian chick exposure to contaminants occurs posthatch as the chick continues to utilize the residual yolk.

Uptake and tissue‐specific distribution of selected polychlorinated biphenyls in developing chicken embryos

“…Liver and brain are important target organs for some of the adverse effects induced by PCBs, but to our knowledge, PCB accumulation in these tissues was not investigated in earlier uptake studies [10,11]. Liver and brain are important target organs for some of the adverse effects induced by PCBs, but to our knowledge, PCB accumulation in these tissues was not investigated in earlier uptake studies [10,11].…”

Uptake of radiolabeled 3,3′,4,4′‐tetrachlorobiphenyl into Japanese quail egg compartments and embryo following air cell and albumen injection

“…As observed in laboratory studies using yolk injections and feeding trials, PCBs readily transfer in the first 70 to 85% of development [60,62]. This would more closely resemble the condition in wild birds, where more than half of the maternally deposited PCB burden is still present in the yolk at hatch [65][66][67][68].…”

“…Because PCBs are highly lipophilic and largely present in the lipid-based yolk in environmentally exposed birds, natural transfer to the embryo via yolk absorption is slow during the first 70 to 85% of development, as observed by de Roode and van den Brink [60] following yolk or air cell injections and also dietary administration [61][62][63]. In wild birds, more than half of the maternally deposited PCB burden is still present in the in the yolk at hatch [64][65][66].…”

Comparison of PCB congener profiles in the embryos and principal prey of a breeding colony of black-crowned night-herons

“…Verreault et al (2006) reported that more heavily chlorinated PCBs tended to be retained in maternal tissues of the glaucous gull (Larus hyperboreus). Similarly, maternal transfer of PCBs from chicken hens to eggs is related to the degree of chlorination (Bargar et al, 2001).…”