and MOON, T. W. 1989. Dove reproduction and retinoid (vitamin A) dynamics in adult females and their eggs following exposure to 3,3',4,4'-tetrachlorobiphenyl. Can. J. Zool. 67:908-913. One week before mating, ring doves (Streptopelia risoria) received an intraperitoneal injection of vitamin-stripped corn oil containing 0 or 40 pglg 3,3',4,4'-tetrachlorobiphenyl. Of numerous reproductive parameters investigated, egg laying was retarded ( p < 0.001) and 43% of the embryos died primarily between days 4 and 7 of incubation in the exposed group. Exposed females laying viable eggs had higher ( p < 0.01) serum retinol at the time of mating than exposed females producing eggs that failed to develop to hatching. Serum retinol concentrations were greater ( p < 0.05) in exposed males than in control males. A method was developed to extract and quantify five naturally occumng retinoids in egg yolks. When the experiment was repeated, yolk retinol and retinyl palmitate decreased ( p < 0.05) between days 3 and 8 of development in the eggs of the exposed group regardless of embryo viability. No change in yolk retinoids occurred in the control group. At day 3 of incubation, the ratio of retinol: retinyl palmitate in yolks was greater ( p < 0.01) in the viable eggs of the exposed group than in either the controls or the nonviable eggs of the exposed group. Despite the reproductive effects, the repeated dose of biphenyl did not elicit liver porphyrin accumulation or alter internal organ weights. Liver retinol concentrations were lower in males ( p < 0.001) and females ( p < 0.05) exposed to the toxicant than in controls; liver retinyl palmitate was unchanged. These changes in retinoid dynamics during oogenesis and in ovo may be a compensatory response to the toxicant. SPEAR, P. A., BOURBONNAIS, D. H., PEAKALL, D. B., et MOON, T. W. 1989. Dove reproduction and retinoid (vitamin A) dynamics in adult females and their eggs following exposure to 3,3',4,4'-tetrachlorobiphenyl. Can. J. Zool. 67 : 908-913. Une semaine avant d'etre accouplies, des Tourterelles h collier (Streptopelia risoria) ont requ une injection intrapkritoine de 0 ou 40 pglg de 3,3',4,4'-tCtrachlorobiphCnyle. Plusieurs paramktres de la reproduction ont Ct C CtudiCs; chez les oiseaux trait&, la ponte des oeufs a CtC retardCe ( p < 0,001) et 43 % des embryons sont morts principalement entre le 4e et le 7e jours de l'incubation. Au moment de l'accouplement, les femelles traitCes dont les oeufs fkconds se sont dCveloppCs normalement ( N normaux *) avaient un taux de rktinol sCrique supCrieur ( p < 0,Ol) h celui des femelles traitCes dont les oeufs fCconds ne se sont pas dCveloppCs jusqu'h 1'Cclosion ((c anormaux B). Les concentrations de rCtinol sirique Ctaient plus ClevCes chez les miles traitCs ( p < 0,05) que chez les tCmoins. Une mCthode permettant d'extraire et de quantifier cinq ritinoi'des dans les jaunes d'oeufs a Cti mise au point. Lorsque I'expCrience a Ct C rCpCtCe, une diminution ( p < 0,05) des concentrations de rCtinol et de palmitate de rktinol a Ct C enregi...

No abstract

: The potential use of retinoids and β-carotene as biomarkers in the eggs of the Great Blue Heron was investigated. In the spring of 1991, 65 eggs were collected from nine heronries (seven along the St Lawrence River and two reference sites). A method was specifically developed for the extraction and analysis of β-carotene and the retinoids in heron egg yolks by reversed-phase HPLC. When results were expressed either as the molar ratio of retinol: retinyl palmitate or as retinyl palmitate concentration, significant differences were found between colonies; however, retinyl palmitate concentration was deemed the better biomarker because it was not significantly influenced by embryonic stage of development. Retinyl palmitate concentrations in freshwater colonies were negatively related to PCB congeners Nos 105 and 118 as well as their TCDD-EQ values (p < 0.02, r (2)=0.78). Egg tetrachloro-mono-ortho biphenyl concentrations were also negatively related to retinyl palmitate (p < 0.005, r (2)=0.90). With the exception of the two mono-ortho co-planar congeners detected in the present study, the contamination levels found in heron eggs were well below those found for other bird species in the Great Lakes area and, so far, no detrimental effects have been reported in Great Blue Heron populations in Quebec. These results suggest that retinyl palmitate may be useful as a sensitive and non-invasive biomarker for monitoring organochlorine contaminant effects in the Great Blue Heron in freshwater sites.

No abstract

Little is known of the combined effects associated with chronic, low‐level exposure of wildlife to the polyhalogenated dibenzo‐p‐dioxins, dibenzofurans, certain biphenyls and other related compounds. To examine possible effects upon egg yolk retinoids, herring gull (Larus argentatus) eggs were collected at early (i.e., days 2–12) and late (i.e., approximately day 20) phases of incubation. Analysis of egg yolks by reversed‐phase high‐performance liquid chromatography revealed compounds that comigrated with all‐trans‐retinol and all‐trans‐retinyl palmitate standards. The retinol concentration and the molar ratio of retinol to retinyl palmitate changed significantly between the early and late phases of incubation. Within the 2‐ to 12‐d period of incubation, however, retinoid values were constant. Gull eggs were collected from two breeding colonies on the Great Lakes in 1986 and from five colonies in 1987. In 2‐ to 12‐d eggs, retinol and retinyl palmitate concentrations were significantly different between gull colonies. The molar ratio of retinol to retinyl palmitate was significantly different between colonies and correlated with several indices of polychlorinated dibenzo‐p‐dioxin and dibenzofuran concentrations quantified in gull eggs from these collection sites. Significant correlations existed between the molar ratio of retinoids and (a) 2,3,7,8‐TCDD concentration, (b) toxic equivalents of PCDDs and PCDFs and (c) the sum of PCDD and PCDF concentrations. These results are discussed in the context of sensitive, bioeffects monitoring.