Organochlorines Affect the Steroid Hormone Cortisol in Free-Ranging Polar Bears (<i>Ursus maritimus</i>) at Svalbard, Norway

Oskam, Irma C.; Ropstad, Erik; Lie, Elisabeth; Derocher, Andrew E.; Wiig, Øystein; Dahl, Ellen; Larsen, Stig; Skaare, Janneche Utne

doi:10.1080/15287390490443731

Cited by 102 publications

(60 citation statements)

References 87 publications

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“…An unexpected outcome of our study was that the 1 mg/kg PCB group vocalized significantly less than the control and 0.1 mg/kg groups, suggestive of a decreased stress response. PCBs are associated with decreased glucocorticoid levels in rat (Durham and Brouwer, 1990), a human in situ system (Li and Wang, 2005), an (Love et al, 2003), polar bears (Oskam et al, 2004) and rainbow trout (Aluru and Vijayan, 2006). Our results suggest that A1221 may be decreasing stress responsiveness in the 1 mg/kg exposed females.…”

mentioning

confidence: 54%

The effects of prenatal PCBs on adult female paced mating reproductive behaviors in rats

Steinberg

Juenger

Gore

2007

Hormones and Behavior

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Polychlorinated biphenyls (PCBs) are a family of toxicants that persist in measurable quantities in human and wildlife tissues, despite their ban in production in 1977. Some PCB mixtures can act as endocrine disrupting chemicals (EDCs) by mimicking or antagonizing the actions of hormones in the brain and periphery. When exposure to hormonally active substances such as PCBs occurs during vulnerable developmental periods, particularly prenatally or in early postnatal life, they can disrupt sex-specific patterning of the brain, inducing permanent changes that can later be manifested as improper sexual behaviors. Here, we investigated the effects of prenatal exposure to the PCB mixture Aroclor (A) 1221 on adult female reproductive behaviors in a dose-response model in the SpragueDawley rat. Using a paced mating paradigm that permits the female to set the timing of mating and control contact with the male during copulation, we were able to uncover significant differences in female-typical sexual activities in A1221-exposed females. Specifically, A1221 causes significant effects on mating trial pacing, vocalizations, ambulation and the female's likelihood to mate. The results further demonstrate that the intermediate treatment group has the greatest number of disrupted endpoints, suggestive of non-linear dose responses to A1221. These data demonstrate that the behavioral phenotype in adulthood is disrupted by low, ecologically relevant exposures to PCBs, and the results have implications for reproductive success and health in wildlife and women. KeywordsAroclor 1221; Paced mating; PCB; Female reproductive behavior; Endocrine disruption Polychlorinated biphenyls (PCBs) were used in industry as inflammable coolants and lubricants and as components of paints and plastics. Banned in 1977 in response to dawning public awareness of their estrogenic and potentially toxic effects on humans and wildlife, PCBs continue to leach into soil, air and groundwater via retired industrial equipment, and from old factories and buildings. PCBs may have variable degrees of impact depending on which congeners or congener mixtures are involved, the organism's age at exposure, the sex of the individual, the degree of exposure and the availability of compensatory diet or social buffering to counteract those effects. An accurate evaluation of ecologically relevant xenobiotic exposure (Battershill, 1994;Brouwer et al., 1999).The neuroendocrine system serves as an interface between the central nervous system and peripheral endocrine organs, and thus represents a prime target for endocrine disruption by PCBs (Patisaul et al., 2006). PCBs and their metabolites can act at multiple nodes of the neuroendocrine axis: they may serve as hormone mimics (Connor et al., 1997), alter circulating hormone levels (Desaulniers et al., 1999), change patterns of estrous cyclicity (Meerts et al., 2004;Buitenhuis et al., 2004), disrupt hormone metabolism Kester et al., 2000;Yamane et al., 1975), influence endocrine-related and hypothalamic gene expression ...

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confidence: 54%

The effects of prenatal PCBs on adult female paced mating reproductive behaviors in rats

Steinberg

Juenger

Gore

2007

Hormones and Behavior

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“…Differences were noted between sexes only for the innermost blubber layer; however, the small sample size for females precludes a complete assessment of the influence of sex on cortisol. Results in the literature regarding sex differences in cortisol are mixed in marine and terrestrial mammals, with some documenting differences among sexes in polar bears (Oskam et al 2004;Macbeth et al 2012) whereas others found no differences in polar bears, grizzly bears, and harbour porpoises (Eskesen et al 2009;Macbeth et al 2010;Bechshoft et al 2013). The higher cortisol levels in the metabolically active inner blubber layer of females compared to males may be a reflection of higher stress conditions or energetic demands in reproductive females (Macbeth et al 2012 and references therein).…”

Section: Cortisol Levels and Variabilitymentioning

confidence: 98%

Cortisol levels in beluga whales (Delphinapterus leucas): Setting a benchmark for Marine Protected Area monitoring

Loseto¹,

Pleskach²,

Hoover³

et al. 2017

Arctic Science

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Beluga whales (Delphinapterus leucas) are facing profound changes in their habitat, with impacts expected at the individual and population level. Detecting and monitoring exposure and response to environmental stressors is necessary for beluga conservation and management of human activities. Cortisol has proven as a useful tool to assess stress on wildlife. Cortisol was measured in three blubber layers and plasma in subsistencehunted beluga whales from the summers of 2007 to 2010 using an HPLC/MS/MS. We assessed the effect of biological and biochemical factors. Cortisol ranged from undetectable to 17.8 ng/g in blubber and 2.5 to 61.2 ng/mL in plasma. Concentrations were highest in the inner blubber layer likely reflecting circulating levels. All tissues were significantly higher in 2008 for reasons that remain unclear. Cortisol levels were on par with resting levels in captive belugas. Best fit models for cortisol revealed age to be an important determinant along with length and blubber thickness. Lack of relationships with biochemical factors such as organic contaminants suggests current cortisol levels are not significantly influenced by present contaminant concentrations. Our findings support the use of middle and outer blubber tissues for an integrated measure of chronic stress that are less subject to the influence of acute stress.

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“…Studies dealing with the effects of CHCs on polar bear health have raised significant concerns. As recently summarized by Fisk et al (2005-this issue), the current understanding of contaminant-induced biological effects in polar bears points to evidence that chronic exposure to CHCs and their metabolites may compromise endocrine functions and homeostasis (Sandau, 2000;Norstrom, 2000;Skaare et al, 2001a;Letcher et al, 2002;Haave et al, 2003;Oskam et al, 2003Oskam et al, , 2004Braathen et al, 2004), immune functions (Bernhoft et al, 2000;Norstrom, 2000Norstrom, , 2001Skaare et al, 2001b;Larsen et al, 2002;Lie et al, 2004aLie et al, , 2005Kirkegaard et al, 2005), cub and reproductive female survival , reproduction and development (Wiig et al, 1998), and hepatic P450-enzymes induction (Bandiera et al, 1995;Letcher et al, 1996).…”

Section: Introductionmentioning

confidence: 99%

Chlorinated hydrocarbon contaminants and metabolites in polar bears (Ursus maritimus) from Alaska, Canada, East Greenland, and Svalbard: 1996−2002

Verreault

Muir

Norstrom

et al. 2005

Science of The Total Environment

125

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A suite of chlorinated hydrocarbon contaminants (CHCs) including organochlorine pesticides (OCPs) and by-products, polychlorinated biphenyls (PCBs), and methyl sulfone (MeSO 2 ) PCB and p,pV-dichlorodiphenyldichloroethylene ( p,pV-DDE) metabolites were determined in adipose tissue of 107 adult and sub-adult polar bears, almost exclusively females, sampled between 1996 and 2002 from populations spanning Arctic and Subarctic regions of Alaska, Canada, East Greenland, and Svalbard. The East Greenland and Svalbard populations of polar bears were distinguished by higher proportions of dichlorodiphenyldichloroethane (DDT)-related compounds, nonachlors, oxychlordane, and higher-chlorinated and persistent PCB congeners (hepta-to nona-chlorinated). Conversely, Alaska, the westernmost population of the North American Arctic, was characterized by higher proportions of relatively volatile compounds such as hexachlorocyclohexanes (HCHs) and pentachlorobenzene (PnCBz), lower-chlorinated PCB congeners (tri-to penta-chlorinated), and lower proportions of oxychlordane. Geometric mean (GM) with 95% confidence limits (CL) AHCH concentrations were highest in Alaska male polar bear fat samples (GM 593; CL 363À909 ng g À 1 lipid weight), ADDT concentration were highest in East Greenland female samples (GM 309; CL 249À490 ng g À 1 l.w.), and A 42 PCB (GM 5972; CL 4637À9129 ng g À 1 l.w.) and AMeSO 2 -PCB (GM 198; CL 162À279 ng g À 1 l.w.) concentrations were highest in female samples collected from Svalbard. The distribution of A-chlordanerelated compounds (ACHL), ACBz, mirex, and dieldrin was relatively uniform among the populations of polar bears investigated. The present 1996À2002 data of female polar bear fat samples was compared to spatial assessments of female polar bear fat samples collected between 1989 and 1993 from comparable populations. The two-point temporal comparisons showed a general decrease for age-adjusted mean concentrations of ACHL, p,pV-DDE, A 42 PCB, AMeSO 2 -PCB and 3-MeSO 2 -p,pV-DDE over a period of approximately 10 years. However, concentrations of dieldrin were comparatively unchanged. Comparisons of present 2001À2002 concentrations in fat of female polar bears from Western Hudson Bay showed great consistency with temporal trends (1991À1999) previously reported for the same region, i.e. the apparent non-decreasing trend of ACHL, h-HCH, AHCH and dieldrin, and the apparent declining trend for APCB. However, present concentrations of a-HCH and ACBz were elevated, and ADDT was notably lower in Western Hudson Bay samples compared to the last measurements in fat samples collected in 1999, which was not in accord with reported temporal trends for this region. As a result of their relatively high degree of contamination, East Greenland and Svalbard polar bears are at higher health risk of contaminant exposure among Arctic and Subarctic populations. In addition to continued biomonitoring, further research on health and population status is needed to evaluate the impact from chronic exposure of polar bear pop...

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Organochlorines Affect the Steroid Hormone Cortisol in Free-Ranging Polar Bears (Ursus maritimus) at Svalbard, Norway

Cited by 102 publications

References 87 publications

The effects of prenatal PCBs on adult female paced mating reproductive behaviors in rats

The effects of prenatal PCBs on adult female paced mating reproductive behaviors in rats

Cortisol levels in beluga whales (Delphinapterus leucas): Setting a benchmark for Marine Protected Area monitoring

Chlorinated hydrocarbon contaminants and metabolites in polar bears (Ursus maritimus) from Alaska, Canada, East Greenland, and Svalbard: 1996−2002

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