Thyroid hormone concentrations in relation to age, sex, pregnancy, and perinatal loss in bottlenose dolphins (Tursiops truncatus)

West, Kristi L.; Ramer, Jan; Brown, Janine L.; Sweeney, Jay C.; Hanahoe, Erin M.; Reidarson, T.; Proudfoot, Jeffry S.; Bergfelt, D.R.

doi:10.1016/j.ygcen.2013.11.021

Cited by 20 publications

(16 citation statements)

References 54 publications

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“…Furthermore, differences in diet and breeding management are likely contributed to variances observed between two breeding centers [ 18 ]. In the present study, T3 levels significantly declined as the age increased, which are consistent with other reports in rats Rattus norvegicus [ 32 ], humans Homo sapiens [ 33 , 34 ], sea lions Eumetopias jubatus [ 6 ], sheep Ovis aries [ 8 ], and dolphins Tursiops truncatus [ 35 ]. Thyroid hormones play a key role in coordinating different factors involved in growth.…”

Section: Discussionsupporting

confidence: 93%

Effects of breeding center, age and parasite burden on fecal triiodothyronine levels in forest musk deer

Wei

Huang

et al. 2018

PLoS ONE

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The objective of this study was to evaluate the effects of sex, breeding center and age on fecal triiodothyronine levels in captive forest musk deer Moschus berezovskii, and to explore the age-intensity model of gastrointestinal parasites. Furthermore, the association between fecal triiodothyronine levels and parasite egg shedding was also analyzed. We collected musk deer fecal samples from two breeding centers located in Shaanxi and Sichuan province, China. Enzyme-linked immunosorbent assays were utilized to estimate the fecal triiodothyronine concentrations and profiles, and fecal parasite eggs or oocysts were counted using the McMaster technique. Female deer from both breeding centers consistently showed higher triiodothyronine concentrations than those observed in males, which indicates that a distinct physiology pattern occurs by sex. The triiodothyronine concentration in Sichuan breeding center was significantly higher than that in Shaanxi center for both sexes, suggesting that differences in environment, diet and management practices are likely to affect the metabolism. In addition, a negative relationship between triiodothyronine concentrations and age was found (r = - 0.75, p < 0.001), and parasite egg shedding was also negatively associated with age (r = - 0.51, p < 0.001), by which we can infer that older animals evolves a more developed immune system. Finally, a positive association between parasite egg shedding and triiodothyronine levels was found, which could be explained by the additional energy metabolism resulting from parasitic infection. Results from this study might suggest metabolic and immunological adaptations in forest musk deer. These baseline data could be used to unveil metabolic status and establish parasite control strategies, which has great potential in captive population management as well as their general health evaluations.

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Section: Discussionsupporting

confidence: 93%

Effects of breeding center, age and parasite burden on fecal triiodothyronine levels in forest musk deer

Wei

Huang

et al. 2018

PLoS ONE

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“…This indicates that successfully pregnant females arrived in the Salish Sea in significantly better nutritional condition, and remained so compared to UPg females that experienced pregnancy loss some time after mid-pregnancy. West et al [25] similarly found significantly higher total T3 concentrations among adult females in successful compared to unsuccessful pregnancies at all stages of gestation among captive dolphins.…”

Section: Discussionmentioning

confidence: 99%

“…T3 may also be blunted under good food conditions when a low metabolism is needed to increase growth (e.g., to accumulate blubber stores in fall, in preparation for the relatively lean winter; [20]). In dolphins, T3 is lower in failed versus successful pregnancies at all stages of gestation [25]. T3 is relatively unresponsive to disturbance stress.…”

Section: Introductionmentioning

confidence: 99%

Population growth is limited by nutritional impacts on pregnancy success in endangered Southern Resident killer whales (Orcinus orca)

Wasser¹,

Lundin²,

Ayres³

et al. 2017

PLoS ONE

127

107

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The Southern Resident killer whale population (Orcinus orca) was listed as endangered in 2005 and shows little sign of recovery. These fish eating whales feed primarily on endangered Chinook salmon. Population growth is constrained by low offspring production for the number of reproductive females in the population. Lack of prey, increased toxins and vessel disturbance have been listed as potential causes of the whale’s decline, but partitioning these pressures has been difficult. We validated and applied temporal measures of progesterone and testosterone metabolites to assess occurrence, stage and health of pregnancy from genotyped killer whale feces collected using detection dogs. Thyroid and glucocorticoid hormone metabolites were measured from these same samples to assess physiological stress. These methods enabled us to assess pregnancy occurrence and failure as well as how pregnancy success was temporally impacted by nutritional and other stressors, between 2008 and 2014. Up to 69% of all detectable pregnancies were unsuccessful; of these, up to 33% failed relatively late in gestation or immediately post-partum, when the cost is especially high. Low availability of Chinook salmon appears to be an important stressor among these fish-eating whales as well as a significant cause of late pregnancy failure, including unobserved perinatal loss. However, release of lipophilic toxicants during fat metabolism in the nutritionally deprived animals may also provide a contributor to these cumulative effects. Results point to the importance of promoting Chinook salmon recovery to enhance population growth of Southern Resident killer whales. The physiological measures used in this study can also be used to monitor the success of actions aimed at promoting adaptive management of this important apex predator to the Pacific Northwest.

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“…In addition to adaptive variations, boto reference ranges provide evidence that thyroid hormone concentrations decrease with age in both males and females, similar to bottlenose dolphins (Fair et al, 2011; West et al , 2014) and belugas (Flower et al, 2015). A decrease in thyroid hormones with age has been observed in humans (Kapelari et al, 2008; Lem et al, 2012) and other mammals (Malinowski et al, 1996) and may in part be explained by growth hormone, which stimulates peripheral T 3 production in young animals (Lapierre et al, 1990).…”

Section: Discussionmentioning

confidence: 94%

“…Aubin, 2001; St. Aubin et al, 1996; West et al, 2014). Comparatively high hormone concentrations and proportionally large thyroid glands of marine cetaceans (Fair et al, 2011; Ridgway and Patton, 1971) have led researchers to speculate that cold environmental temperatures combined with high heat conductivity of water habitats requires an increased metabolic response to maintain core body temperature, which is driven by enhanced thyroid activity.…”

Section: Introductionmentioning

confidence: 99%

Thyroid hormone concentrations associated with age, sex, reproductive status and apparent reproductive failure in the Amazon river dolphin (Inia geoffrensis)

Robeck

Amaral

Silva

et al. 2019

Conservation Physiology

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This study was conducted to characterize immunoreactive thyroid hormone concentrations in wild Amazon river dolphins, also called boto (Inia geoffrensis) by age group, sex, pregnancy and lactation status, and to determine if thyroid hormone concentration differences could be detected between pregnant females with and without successful parturition outcomes. Radioimmunoassays were used to analyse total T3 and total T4 in 182 serum samples collected from 172 botos living in the Mamirauá Sustainable Development Reserve, in the Brazilian Amazon from 2003 through 2015. Age significantly affected tT3 and tT4 concentrations in males, with values in immature males and females being significantly lower than those in adult males, whereas no age effects were noted between immature females and adult non-pregnant, non-lactating females. Significant sex differences were noted in tT3 concentrations between immature males and females and in tT4 concentrations between adult males and females. These resulted in significant differences in the tT3:tT4 ratio between males and females within the immature and adult groups. Lactating and non-pregnant adult females had significantly higher tT3 concentrations than pregnant females, and this difference was primarily driven by a 12% drop in tT3 concentrations during the last two-thirds of pregnancy. No differences in thyroid hormone concentrations were detected between females diagnosed as pregnant and later found to have or not have a live calf. These results are the first to define thyroid hormone reference intervals and normal physiological variations in a wild population of river dolphins.

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Thyroid hormone concentrations in relation to age, sex, pregnancy, and perinatal loss in bottlenose dolphins (Tursiops truncatus)

Cited by 20 publications

References 54 publications

Effects of breeding center, age and parasite burden on fecal triiodothyronine levels in forest musk deer

Effects of breeding center, age and parasite burden on fecal triiodothyronine levels in forest musk deer

Population growth is limited by nutritional impacts on pregnancy success in endangered Southern Resident killer whales (Orcinus orca)

Thyroid hormone concentrations associated with age, sex, reproductive status and apparent reproductive failure in the Amazon river dolphin (Inia geoffrensis)

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