Seasonal thyroid hormone levels of free-ranging white-tailed deer (Odocoileus virginianus) in Ontario

1990 ◽  
Vol 68 (10) ◽  
pp. 2174-2180 ◽  
Author(s):  
J. Hamr ◽  
G. A. Bubenik

Blood samples from killed and livetrapped deer of southern and central Ontario were analyzed for thyroxine (T4) and triiodothyronine (T3). Mean seasonal levels for six sex-age classes of deer ranged from 150 to 400 ng/dL (T3) and from 6.0 to 18.0 μg/dL (T4). Seasonal variation of T4 was less pronounced than that of T3. Both hormones decreased in the fall as compared with spring and summer, especially in yearling and older bucks. T3 values were also low in the winter but increased in spring and summer for most tested categories of deer. Differences in seasonal T3 and T4 concentrations were found between male and female deer older than 1 year, and among sex-age classes of the same sex. Regional differences in thyroid hormone levels suggested a latitudinal gradient, with higher values in southern than in central Ontario. Hormone of artificially fed deer were elevated when compared with animals that consumed only natural browse. Hormone levels were also higher in deer provided with food supplements of higher protein content. Extremely low winter T3 and T4 concentrations were found in malnourished deer. It is concluded that thyroid hormones in deer blood are influenced by current food intake and quality of nutrition. The potential for T3 and T4 as indicators of range quality is discussed.

Toxics ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 16
Author(s):  
Pornpimol Kongtip ◽  
Noppanun Nankongnab ◽  
Ritthirong Pundee ◽  
Nichcha Kallayanatham ◽  
Sumate Pengpumkiat ◽  
...  

The objective of this study was to investigate the relationship of acute pesticide exposures and acute changes in thyroid hormones among Thai farmers. We recruited 78 farmers, who were scheduled to spray insecticides (chlorpyrifos and/or cypermethrin) or herbicides (paraquat and/or glyphosate). On the day before spraying, farmers collected their first morning void urine and went for blood collection. On the spray day, urine samples were collected at end of the spraying event and they were interviewed with questionnaires. The next morning, the first morning void urine and blood samples were collected. Blood samples were analyzed for thyroid hormones. Urine samples were analyzed for the metabolites of the pesticide sprayed. The results showed that the thyroid hormones, free triiodothyronine (FT3) and total triiodothyronine (T3) were significantly reduced as urinary chlorpyrifos metabolite increased the day after spraying. Total thyroxine (T4) significantly increased as cypermethrin metabolites increased the day after spraying. T4 significantly increased as urinary glyphosate levels increased; however, FT3 and T3 decreased significantly as urinary paraquat levels increased the day after spraying. These findings suggest that acute exposures to the pesticides chlorpyrifos, cypermethrin, paraquat and glyphosate can produce acute effects on the hypothalamic–pituitary–thyroid (HPT) axis, acutely altering thyroid hormone levels.


2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Laura Pujade Busqueta ◽  
Daniel E Crocker ◽  
Cory D Champagne ◽  
Molly C McCormley ◽  
Jared S Deyarmin ◽  
...  

Abstract Evaluating the impacts of anthropogenic disturbance on free-ranging marine mammal populations, many of which are in decline, requires robust diagnostic markers of physiological stress and health. However, circulating levels of canonical ‘stress hormones’ such as glucocorticoids, which are commonly used to evaluate animal health, do not capture the complexity of species-specific responses and cannot be easily measured in large, fully aquatic marine mammals. Alternatively, expression of stress-responsive genes in hormone target tissues such as blubber, the specialized subcutaneous adipose tissue that can be manually or remotely sampled from many marine mammals, may be a more informative and sensitive indicator of recent (within 24 h) exposure to stressors. We previously identified genes that were upregulated in the inner blubber of juvenile northern elephant seals during experimental stimulation of the hypothalamic–pituitary–adrenal axis. In this study, we measured baseline expression levels of a subset of these genes in inner blubber of unmanipulated juvenile elephant seals of varying physiological states and correlated them with other stress markers (body condition index, corticosteroid and thyroid hormone levels). Expression of 10 genes, including those associated with lipid metabolism (ACSL1, HMGCS2, CDO1), redox homeostasis (GPX3), adipokine signaling (ADIPOQ), lipid droplet formation (PLIN1, CIDEA) and adipogenesis (DKK1, AZGP1, TGFBI), was described by three principal components and was associated with cortisol and thyroid hormone levels. Significantly, baseline gene expression levels were predictive of circulating hormone levels, suggesting that these markers may be potential indicators of exposure to stressors in marine mammal species that are inaccessible for blood sampling. A similar approach may be used to identify species-specific stress markers in other tissues that can be sampled by remote biopsy dart from free-ranging marine mammals, such as outer blubber and skin.


2015 ◽  
Vol 16 (2) ◽  
pp. 78
Author(s):  
Umit Kervan ◽  
Anil Ozen ◽  
Utku Unal ◽  
Irfan Tasoglu ◽  
Mahmut Mustafa Ulas ◽  
...  

<p><b>Objective:</b> The aim of this study was to examine the effects of positive inotropic drugs, including adrenaline, dopamine, and dobutamine on thyroid hormone levels following open heart surgery.</p><p><b>Methods:</b> We analyzed free thyroid hormones (FT3 and FT4) and thyroid-stimulating hormones (TSH) in 200 consecutive patients undergoing open heart surgery. Patients were divided into 5 groups according to the inotropic drug administration as follows: Group A (n = 46) received dopamine alone; Group B (n = 40), dopamine and dobutamine; Group C (n = 36), dopamine, dobutamine, and adrenaline; Group D (n = 32), adrenaline alone; and Group E (n = 46), placebo. Procedural factors affecting thyroid hormones were recorded and included cardiopulmonary bypass (CPB) time, cross-clamping time, degree of hypothermia, and the duration and doses of positive inotropic drugs. Blood samples for hormone assays were collected before initiation of inotropic drug therapy (baseline) and postoperatively at 24, 72, and 120 hours after drug therapy.</p><p><b>Results:</b> FT3, FT4, and TSH levels at baseline were similar in all groups. Although there was a trend showing very slight increases in thyroid hormone levels from baseline to the 24th, 72nd, and 120th postoperative hours after drug therapy, these changes were not significant, and there were also no significant differences between the groups. There was also no significant statistical difference in CPB time, cross-clamping time, degree of hypothermia, and duration and doses of positive inotropic drugs between groups.</p><p><b>Conclusion:</b> Although thyroid hormone levels were affected by positive inotropic drug usage after open heart surgery, this effect was not significant and thyroid hormone levels remained within normal ranges.</p>


2020 ◽  
Vol 33 (5) ◽  
pp. 653-659
Author(s):  
Jia Song ◽  
Yun Cui ◽  
Chunxia Wang ◽  
Jiaying Dou ◽  
Huijie Miao ◽  
...  

AbstractBackgroundThyroid hormone plays an important role in the adaptation of metabolic function to critically ill. The relationship between thyroid hormone levels and the outcomes of septic shock is still unclear. The aim of this study was to assess the predictive value of thyroid hormone for prognosis in pediatric septic shock.MethodsWe performed a prospective observational study in a pediatric intensive care unit (PICU). Patients with septic shock were enrolled from August 2017 to July 2019. Clinical and laboratory indexes were collected, and thyroid hormone levels were measured on PICU admission.ResultsNinety-three patients who fulfilled the inclusion criteria were enrolled in this study. The incidence of nonthyroidal illness syndrome (NTIS) was 87.09% (81/93) in patients with septic shock. Multivariate logistic regression analysis showed that T4 level was independently associated with in-hospital mortality in patients with septic shock (OR: 0.965, 95% CI: 0.937–0.993, p = 0.017). The area under receiver operating characteristic (ROC) curve (AUC) for T4 was 0.762 (95% CI: 0.655–0.869). The cutoff threshold value of 58.71 nmol/L for T4 offered a sensitivity of 61.54% and a specificity of 85.07%, and patients with T4 < 58.71 nmol/L showed high mortality (60.0%). Moreover, T4 levels were negatively associated with the pediatric risk of mortality III scores (PRISM III), lactate (Lac) level in septic shock children.ConclusionsNonthyroidal illness syndrome is common in pediatric septic shock. T4 is an independent predictor for in-hospital mortality, and patients with T4 < 58.71 nmol/L on PICU admission could be with a risk of hospital mortality.


1983 ◽  
Vol 104 (1) ◽  
pp. 1-5 ◽  
Author(s):  
J. Leppäluoto ◽  
L. Rönnberg ◽  
P. Ylöstalo

Abstract. Seven patients suffering from severe endometriosis were treated with danazol 200 mg × 3 daily for 6 months. Clinical symptoms were alleviated and menses disappeared in response to the treatment. After cessation of the treatment the menstrual bleedings returned in 1–3 months. Blood samples for determination of gonadotrophins, prolactin (Prl), oestradiol (E2), progesterone, thyroid hormones and thyrotrophin in radioimmunoassays were taken and a combined TRF and LRF test carried out in the follicular phase before treatment, at the 6th month of treatment and after reappearance of the first menses. There were no statistically significant changes in the basal levels of serum FSH, LH or TSH during the danazol treatment. Neither was there any change in episodic secretions of FSH, LH or Prl, as determined by the mean coefficients of variation of the hormone levels in seven consecutive samples taken at 20 min intervals. On the other hand, serum E2, Prl and thyroid hormone levels were significantly decreased in the 6th month of treatment. In the TRF-LRF test the responses of serum FSH and LH were significantly higher and those of serum Prl and TSH significantly lower during danazol treatment than before. Prl responses remained lowered after the treatment. It appears that low serum oestrogen levels, induced by the danazol treatment, sensitize the pituitary gonadotrophs to exogenous LRF, but make the sensitivity of thyrotrophs and lactotrophs lower to exogenous TRF. These results thus indicate that danazol does not make the pituitary gonadotrophs insensitive to LRF, but danazol may rather inhibit the secretion of hypothalamic LRF.


2013 ◽  
Vol 5 (01) ◽  
pp. 26-29 ◽  
Author(s):  
Abiodun Mathias Emokpae ◽  
Aliyu Abdu ◽  
Humphrey Benedo Osadolor

ABSTRACT Background: High blood pressure (BP) is a major health problem in Nigeria and the involvement of thyroid hormones in this condition has not been evaluated in this center. Objective: The objective of this study was to evaluate the proportion of patients with an essential hypertension who had abnormal thyroid hormone levels and the type of thyroid disorders commonly observed in this group of patients. Materials and Methods: A retrospective study of 94 patients (30 males, aged 30.4 ± 2 years and 64 females, aged 43.4 ± 1.3 years) with essential hypertension was carried out between January 2005 and December 2007. Demographic and other medical information were obtained from the health records. Analysis of laboratory results of triiodothyronine (T3), Thyroxine (T4), and thyroid stimulating hormone (TSH) were made. Results: Of the 94 patients evaluated, 26 (27.7%) had abnormal thyroid hormone levels, with 23.4% having hyperthyroidism, 4.3% had sub-clinical hypothyroidism and none had overt hypothyroidism. Of the 26 subjects with abnormal thyroid hormone levels, 18 (69.2%) were females while 8 (30.8%) were males. Out of the 18 female subjects with abnormal thyroid hormone levels, 16 had hyperthyroid levels while 2 had sub-clinical hypothyroid levels. Out of the 8 male patients, 6 had hyperthyroid hormone levels while 2 had sub-clinical hypothyroid levels. Conclusion: Thyroid hormone abnormalities are common in patients with essential hypertension. Hyperthyroidism was the most common thyroid disorder observed. Young patients presenting with essential hypertension should be screened for thyroid hormone abnormalities since they can best be managed by treating the underlying causes.


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