Triiodothyronine Concentrations Research Articles

138 Growth performance and physiological response of nursery pigs fed a high canola meal diet with acidifiers

Abstract This study investigated the impact of feed additives aimed at reducing gut pH on the growth performance and physiological responses of nursery pigs when fed a high canola meal (CM) diet. A total of 315 nursery pigs, 6.0 ± 1.2 kg body weight (BW), were allotted to one of five dietary treatments with 9 replicates (7 pigs/pen) in a randomized complete block design. Dietary treatments were PC: corn-soybean meal-based diet with 20% CM, NC: corn-soybean meal-based diet with 40% CM; NC+A: NC diet with acidifier at 1,500 ppm, NC+B: NC diet with encapsulated butyrate at 500 ppm, and NC+A+B: NC diet with acidifier and encapsulated butyrate. All diets were formulated to meet or exceed the nutrient requirements of NRC (2012). All pigs received a common Phase 1 nursery diet during week 1 following weaning. Experimental diets were provided in Phase 2 (wk 2 and 3) and Phase 3 (wk 4 to 6). Individual pig BW and pen feed consumption were measured for each phase to calculate growth performance. At the conclusion of each phase, blood samples were collected from one pig per pen for analysis of serum triiodothyronine (T3) and thyroxine (T4) concentrations. The selected pig was euthanized within 24 h, and its organ weights and pH of digesta were measured. The results were analyzed using MIXED procedure in SAS with the pen as an experimental unit. There was no difference in BW and average daily gain throughout the overall period. However, PC treatment exhibited greater (P < 0.05) average daily feed intake in phase 3 by 18.2% and overall period by 13.4% compared with NC treatment and no difference with NC+A+B treatment. The NC+A and NC+A+B treatments tended to improve (P ≤ 0.10) gain to feed ratio in phase 3 by 17.9% and overall period by 16.1% compared with PC treatment, respectively. At the end of phase 3, the PC treatment tended (P < 0.10) to have greater serum T4 concentrations compared with NC and NC+A treatments (3.2 vs 2.5 and 2.4 ug/dL, respectively), whereas there was no difference between PC and NC+A+B treatments. In phase 3, the thyroid gland weight for PC treatment was less (P < 0.05) than for NC treatment (0.156 vs 0.202 g/kg), whereas there was no difference among PC, NC+B, and NC+A+B treatments. In phase 3, dietary encapsulated butyrate decreased (P < 0.05) the pH of jejunal digesta compared with PC treatment (6.28 vs 7.01), and dietary encapsulated butyrate treatments (NC+B and NC+A+B) tended to decrease (P < 0.10) the pH of hind-colonic digesta compared with the pH of PC treatment by 6.2% and 7.2%. In conclusion, dietary encapsulated butyrate in combination with acidifier may alleviate thyroid dysfunction that is anti-nutritional effect of high canola meal diets.

Ontogenetic transition from aquatic to amphibious life in the mudskipper, Periophthalmus modestus

Vertebrates first emerged from water to land in the Paleozoic. Our understanding about the process has been steadily refined through paleontological studies, although the soft-body traits and behavior of these early animals remain poorly known. Mudskippers, extant amphibious gobies, could give insight into this question. This study reports on the ontogenetic transition from water to land of the mudskipper Periophthalmus modestus under laboratory conditions. After about 30 days after hatching (dah), the fish gradually changed their preference from water to an artificial shore and then to land. After about five days of periodic volitional emersion, the fish became able to propel themselves on land using the pectoral fins and after a further 13 days they began feeding on land. During the transition, the head morphology altered to suit for terrestrial existence. Tissue contents of triiodothyronine (T3) and thyroxine (T4) sharply increased at 30 dah. Forced underwater confinement of larvae at the last pelagic stage (27-29 dah) for 40-42 days resulted in no statistically significant difference in survival or gross morphology of the body and the gills. Growth was slightly stimulated. Our results show that mudskippers emerge on land with little morphological alteration during ontogenesis, much less than the changes observed for amphibians, and that emersion was not indispensable for survival or growth under our laboratory conditions. Further analysis of how and why mudskippers make their way across the water’s edge will shed valuable light on what morphological, behavioral and physiological traits were needed for, and what environmental conditions may have driven the earliest steps of the water-to-land transition in ancient fishes.

Total thyroxine, triiodothyronine, and thyrotropin concentrations during acute nonthyroidal illness and recovery in dogs.

Acute illness can result in changes in serum total thyroxine (tT4), total triiodothyronine (tT3), and thyrotropin (TSH) concentrations in euthyroid dogs defined as nonthyroidal illness syndrome, but longitudinal evaluation of these hormones during the recovery phase is lacking. To longitudinally evaluate serum tT4, tT3, and TSH concentrations during the acute phase and recovery from acute illness in dogs. Nineteen euthyroid client-owned dogs hospitalized for acute illness at a veterinary teaching hospital. Prospective longitudinal study. Serum tT4, tT3, and TSH concentrations were measured at the admission (T0), at last day of hospitalization (T1), and during the recovery phase at 3, 7, 14, and 21 days after the discharge (T2, T3, T4, and T5), respectively. tT4 and tT3 were below the reference interval (RI) at T0 in 3 (16%) and 18 (95%) dogs, respectively; tT4 normalized in all dogs early in the recovery phase, while low tT3 persisted at the end of the study in 16 (83%) dogs. Median TSH concentrations were increased at T5 compared with T1 (0.19 ng/mL [range 0.03-0.65] vs 0.11 ng/mL [range (0.05-0.26)], mean difference = 0.09 ng/mL; P = .03). Five (26%) dogs had TSH above the RI at least at 1 time point during the recovery phase. None of the dogs had concurrent low tT4 and high TSH during the study. In euthyroid dogs acute illness can interfere with evaluation of thyroid function up to 21 days during the recovery phase. Thyroid testing should be avoided or postponed in these dogs.

Calculation of reference intervals for indicators of thyroid hormones and cortisol in horses

The article discusses the results of calculating reference intervals for thyroid hor mones and cortisol in adult horses. The study included the results of a laboratory study of the concentrations of total triiodothyronine, total and free thyroxine and cortisol from 50 horses aged 3 to 29 years, including 17 mares, 13 stallions and 20 geldings. All animals underwent an extensive biochemical blood test, the results of which revealed no pathological changes.To calculate the normative limits of fluctuations for each hormone, calculations were carried out using the Tukey method, which is used to determine the reference limits in the case of a small number of variants in the group and the absence of a normal distribution. Microsoft Excel was used for calculations. The conducted studies made it possible to clarify the reference intervals for thyroid hormones and cortisol in horses, which were: total triiodothyronine (T3) - 1.13-4.04 nmol/l, total thyroxine (T4) - 20.97-57.42 nmol/l, free thyroxine (fT4) 7.38-23.07 pmol/l, cortisol – 39.42-227.02 nmol/l. The results obtained can be recommended for use not only for the clinical and biochemical laboratory of St. Petersburg State University of Medicine, but also for all veterinary laboratories using diagnostic test systems for enzyme immunoassay of Vital Development Corporation.

Performance, HSP70 expression, antioxidant enzymes, oxidative DNA damage biomarkers, metabolic hormones, and intestinal microbiota of broiler chickens fed mistletoe leaf powder supplemented diets under tropical high ambient temperatures

The study investigated the impact of Mistletoe Leaf Powder (MLP) supplementation on some parameters in heat-stressed broiler chickens. The standard baseline diets, comprising four different formulations, were provided during the starter and finisher stages. Chickens were randomly assigned to the 4 dietary groups: a negative control (CON) with no supplementation, a positive control (VTC) with 200 mg/kg vitamin C, and 2 experimental treatment groups with 2500 mg/kg (MLP2) and 5000 mg/kg (MLP5) MLP supplementation. The Body Weight Gain (BWG) in MLP2 and MLP5 treatment groups was comparable (P > 0.05) to those in VTC, while the CON group exhibited significantly (P < 0.05) lower BWG. Feed consumption was significantly (P < 0.05) lower broiler chickens in the CON group compared to those VTC, MLP2, and MLP5. Heat shock protein 70 (HSP70) levels were lower in broiler chickens belonging to VTC, MLP2, and MLP5 groups compared to those in CON, and MLP2 showed no difference (P > 0.05) from MLP5 and VTC. Serum glutathione peroxidase and catalase concentrations were higher (P < 0.05) in birds belonging to MLP5, MLP2, and VTC groups compared to CON. The 8-hydroxy-2′-deoxyguanosine concentration was lower (P < 0.05) in birds of VTC, MLP2, and MLP5 compared to the CON, with VTC showing the least concentration. Serum insulin levels were higher (P < 0.05) in MLP5 compared to those in CON, while serum triiodothyronine and leptin concentrations were lower (P < 0.05) in CON compared to birds in VTC, MLP2, and MLP5. Microbiota analysis revealed that the Coliform bacteria population was higher (P < 0.05) in birds belonging to CON compared to those in VTC, MLP2, and MLP5 groups, whereas lactic acid-producing bacteria were significantly (P < 0.05) lower in birds of CON and highest in MLP2 and MLP5 groups. In conclusion, dietary supplementation of MLP at 5000 mg/kg enhanced performance, oxidative status, influenced metabolic hormones, and gut microbiota in broiler chickens raised under high ambient temperature.

Assessment of Haematological, Biochemical and Hormonal Changes in Mehsana buffaloes with Postpartum True Anestrus following Herbal Heat Inducer Treatment

The present study was designed to explore the effects of a new Herbal heat inducer in Mehsana buffaloes with postpartum true anestrus and consecutive changes in Blood haematological, Biochemical and Hormonal profile. All the buffaloes were orally supplemented with Herbal heat inducer mixture on (Jantana powder-10gm) 1st, (Metrali powder-20gm) 2nd and (Hitali-powder-500mg) 5th day for augmentation of oestrus. Out of total treated animals 10 animals expressed the signs of estrus within 30 days. Post-treatment analysis of the overall blood packed cell volume percent in conceiving buffaloes had a significant (p≤0.05) elevate. Overall blood plasma total cholesterol concentration (mg/dl) was found to be significantly (p≤0.001) elevated in all treated and both conceiving and non-conceiving buffaloes, respectively. Overall blood plasma progesterone concentration (ng/ml) was found to be significantly (p≤0.0001) and (p≤0.001) elevated in all treated and both conceived and non-conceived buffaloes, which indicate the positive favourable effect of all the drugs on postpartum true anestrus condition. However, Overall blood plasma tri-iodothyronine concentration (ng/ml) was found to be significantly (p≤0.001) and (p≤0.01) elevated in all treated and all conceived buffaloes. Findings of the present study revealed that strategic use of Indigenous herbal heat inducer in feed mixture may resolve the postpartum true anestrus problems in buffaloes.

Meta-analysis of organic chromium dietary supplementation on growth performance, carcass traits, and serum metabolites of lambs

There are inconsistent results on the effects of organic chromium (OCr) dietary supplementation on productivity, carcass traits, and blood metabolites of sheep. Therefore, this study aimed to evaluate the effects of OCr dietary supplementation on growth performance, carcass traits, meat composition, and serum metabolites of lambs using a meta-analytical approach. The final database included 16 studies from which the variables of interest were obtained. Data were analyzed using a random effects model, and results are presented as weighted mean differences (WMD) between OCr-supplemented and non-OCr treatments. OCr dietary supplementation did not affect dry matter intake; however, average daily gain increased, and feed conversion ratio decreased in response to OCr dietary supplementation. Dietary supplementation with OCr increased hot carcass weight, hot carcass yield, cold carcass weight, and Longissimus dorsi muscle area but decreased backfat thickness. In meat, OCr supplementation increased Warner-Bratzler shear force and protein content and decreased intramuscular fat content. In the blood, OCr dietary supplementation increased the serum concentration of insulin and triiodothyronine. However, serum concentrations of glucose, cholesterol, triglycerides, and thyroxine decreased in response to OCr dietary supplementation. In conclusion, organic chromium can be used as a dietary additive to improve average daily gain and feed conversion ratio in lambs and, at the same time, improve carcass traits, meat chemical composition, and serum metabolites.

Energy-Related Hormones in Raw and Retail Cow’s Milk and Possible Risk for Consumers

Abstract The study aimed to determine the concentration of energy-related hormones in cow’s milk and to consider them from a public health perspective. Fourteen Holstein cows were subjected to milk and blood sampling on the following days in lactation (DIL): 10, 30, 60, 90, 150, 180, 210, 250 and 280 to determine milk hormones, fat and protein content and blood biochemical parameters. For the same purpose, bulk-tank milk was sampled and samples of retail m ilk with 1.5% (CM1.5) and 3.2% (CM3.2) fat was purchased. Milk insulin-like growth factor-1 (IGF-1) values were significantly lower at 90, 150, 180, 210 and 250 and significantly higher at 10, 30 and 60 DIL than lactation average (LA). Milk insulin concentrations were significantly lower at 30, 60 and 90 and higher at 210, 250 and 280 DIL than LA. Free thyroxine (fT4) level in the milk was higher at 250 DIL, while milk free triiodothyronine (fT3) concentrations were lower at 30, 60, 90 and 280 DIL, and significantly higher at 10 and 180 DIL than respective LA. Milk cortisol levels were lower at 60 and 280 DIL than LA. All measured milk hormones were significantly lower in CM1.5 compared to CM3.2, bulk-tank milk and LA. An exception was the LA of IGF-1, which was significantly lower than the IGF-1 content in CM1.5. Blood biochemical parameters fluctuated evenly during lactation and were within the reference range. Hormone concentrations in cow’s milk fluctuate during lactation, giving milk an important role in the context of public health.

Effect of acupuncture on Hashimoto thyroiditis: A systematic review and meta-analysis.

Hashimoto thyroiditis (HT) is a common autoimmune thyroid disease for which there is no specific treatment. Oral levothyroxine sodium tablets significantly improved thyroid function but did not promote a reduction in thyroid-related antibody concentrations. Acupuncture can improve clinical symptoms and thyroid function in HT patients, reduce serum TPOAb and TGAb levels in HT patients, and improve patients' quality of life. We conducted a systematic review and meta-analysis to evaluate the effect of acupuncture versus levothyroxine sodium tablets on Hashimoto thyroiditis. We searched Web of Science, Embase, China National Knowledge Infrastructure, WanFang, VIP, SinoMed and the Cochrane Central Registry of Controlled Trials to identify candidate randomized controlled trials (RCTs). A total of 1020 patients participated in 14 randomized controlled trials. The results of meta-analysis showed that acupuncture regulated TPOAb content (mean difference [MD] = -63.18, 95%CI = -91.73 to -34.62, P < .00001), TGAb content (MD = -68.56, 95%CI = -101.55 to -35.57, P < .00001), serum free triiodothyronine (FT3) content (MD = 0.74, 95%CI = 0.20 to 1.27, P < .00001), serum free thyroxine (FT4) content (MD = 1.10, 95%CI = 0.29 to 1.92, P < .00001), TSH content (MD = -2.16, 95%CI = -3.14 to -1.19, P < .00001) had a significant effect. Compared with levothyroxine sodium tablets alone, acupuncture can significantly regulate the contents of TPOAb, TGAb, FT3, FT4 and TSH.

Physiological responses on the reproductive, metabolism and stress endpoints of Astyanax lacustris females (Teleostei: Characiformes) after diclofenac and ibuprofen exposure

Diclofenac (DCF) and ibuprofen (IBU) are pharmaceutical compounds frequently detected in aquatic compartments worldwide. Several hazard effects including developmental abnormalities and redox balance impairment have been elucidated in aquatic species, but multiple endocrine evaluations are scarce. Therefore, the present study aimed to assess the disruptive physiological effects and toxicity of DCF and IBU isolated and combined, using females of the native freshwater teleost Astyanax lacustris. In regards to NSAIDs bioavailability, the results showed absence of degradation of IBU and DCF after 7 days of exposure. IBU LC50 for A. lacustris was 137 mgL−1 and females exposed to IBU isolated increased thyroxine (T4) concentration at 24 h and decreased after 96 h; DCF exposure decreased triiodothyronine (T3) concentration at 96 h. Circulating levels of 17β-estradiol (E2), cortisol (F) and testosterone (T) were not affected by any treatment. HPG and HPI axis genes fshβ, pomc and vtg were upregulated after 24 h of IBU exposure, and dio2 was downregulated in DCF fish exposed group after 96 h compared to the mixture. Protein concentration was reduced in muscle and increased in the liver by DCF and mixtures exposures at 24 h; while liver lipids were increased in the mixture groups after 96 h. The study point out the capacity of NSAIDs to affect endocrine endpoints in A. lacustris females and induce changes in energetic substrate content after acute exposure to isolated and mixed NSAIDs treatments. Lastly, the present investigation brings new insights into the toxicity and endocrine disruptive activity of NSAIDs in Latin America teleost species and the aquatic environment.

Association between TPO gene polymorphisms with susceptibility to hyperthyroidism

Introduction and Aim: Hyperthyroidism is a disorder characterized by excessively high amounts of tri-iodothyronine and thyroxine in the bloodstream. TPO is a thyroid-specific antigen. TPO gene mutations affect thyroid hormone synthesis, causing full or partial iodide organification abnormalities. In this study, we aimed to look at the single nucleotide polymorphisms (SNPs) in the TPO gene and find possible relation of these SNPs to the development or prognosis of hyperthyroidism.   Materials and Methods: Blood samples were collected from hyperthyroid patients (n=75) and healthy individuals (n=25). The concentration of triiodothyronine (T3), Tetra-iodothyronine (T4), and thyroid stimulating hormone (TSH) were estimated in all samples. The autoantibodies TPOAbs and TR-Ab levels were measured using the ELISA assay. The extracted genomic DNA from blood of participants was investigated for polymorphism in the SNPs rs1126799, rs1126797, and rs732609 within the TPO gene. Statistical methods were used to evaluate the association between the TPO SNPs studied to hyperthyroidism susceptibility.   Results: No significant correlation was observed between the SNPs studied and prognosis of hyperthyroidism. However, it was found that hyperthyroid patients carrying the TPO rs1126799 T allele (CT + CC genotypes) had significantly higher serum levels of TPOAb compared to those with the TT genotype (P&lt;0.01). Similarly, hyperthyroid patients with the TPO rs1126797 C allele (CT + TT genotypes) and TPO rs732609 A allele (CA + AA genotypes) exhibited significantly elevated levels of TPOAbs compared to individuals with the CC genotype and AA genotype, respectively (P&lt;0.01).   Conclusion: There was no correlation between the TPO rs1126799, rs1126797, and rs732609 polymorphisms with the occurrence of hyperthyroidism in the Iraqi population. However, TPO rs2071400 and rs2048722 polymorphisms were found to be correlated to serum levels of TPOAb.

Influence of mother’s genotype on the concentration and variability of triiodothyro- nine in landrace pigs

   One of the leading roles in the hormonal system of the body of pigs in terms of functional significance is played by the thyroid gland, which, through the hormone triiodothyronine, has a complex effect on all systems, organs and physiological processes while controlling the metabolism and energy in the animal’s body. The impact of maternal genotype on the concentration and variability of triiodothyronine in complete siblings of Landrace pigs was studied. For the study, blood serum samples were taken from 33 pigs using the vacuum method from the jugular vein. Blood samples were taken according to generally accepted practices. The studies were carried out in the laboratory of the biochemistry of the Novosibirsk State Agrarian University using the technique of competitive enzyme immunoassay with a set of reagents “Steroid ELISA-triiodothyronine” to quantify the concentration of triiodothyronine in blood serum. Enzyme immunoassay was performed on a Thermo Scientific Multiskan FC analyser. In pig breeding, the content of heavy metals in water, soil, feed, organs and tissues was constantly monitored. The concentration of chemical elements did not exceed the MPC level. Statistical processing of experimental data was carried out using standard methods of descriptive statistics and the statistical programming language or data analysis environment RStudio (using the functions: descrstats, summary, sd, read.table, write. table, aes). The strength of the influence of the genotype of mothers of the Landrace breed on the triiodothyronine content in complete siblings in the conditions of Western Siberia was established, which amounted to 4.6 %. In some mothers’ offspring, the triiodothyronine level was 1.9 and 1.8 times higher than in others. Two clusters of mothers were identified according to the concentration of triiodothyronine in complete siblings, which included three groups of mothers with an average level of 2.26 nmol/l and five groups with the attention of 1.30 nmol/l. The reference limits of the triiodothyronine level in Landrace pigs in the conditions of Western Siberia were established.

Sustained Euthyroidism during Thionamide Antithyroid Drug Treatment: Comparison of Short- and Long-term Methimazole Therapy

Background: Extended low serum thyrotropin (TSH) levels may increase the risk of cardiovascular events in patients with hyperthyroidism. Objectives: This study aimed to compare the time spent with sustained normal TSH concentration following short- and long-term methimazole treatment. Methods: A total of 258 patients with Graves’ hyperthyroidism completed 18 - 24 months of methimazole therapy and were randomized to discontinue treatment (n = 128, short-term group) or continue an additional 36 - 102 months of methimazole therapy (n = 130, long-term group). Clinical and laboratory evaluations were performed every 6 months for 132 months after randomization. Results: There was no difference in serum-free thyroxine, triiodothyronine, and TSH concentrations between the 2 groups at the time of randomization. Of 128 patients in the short-term group, 5 left in follow-up, 2 became hypothyroid, 67 (54%) had a relapse of hyperthyroidism, and only 54 (44%) were euthyroid at the end of the study. Among 130 patients on the long-term methimazole therapy, 4 were left in follow-up, 24 developed hyperthyroidism, 4 developed hypothyroidism, and 98 (78%) were euthyroid 132 months post-randomization. Total time spent on euthyroidism was 90.4% ± 8.1% of the study period in the short-term and 95.8% ± 7.0% in the long-term treatment groups (P &lt; 0.001). The lowest time spent in euthyroidism (74.6% ± 6.4% of the study period) belonged to 29 (24%) patients in the short-term group under levothyroxine therapy because of fluctuation in serum TSH. Patients in both groups with hyperthyroidism relapse who chose methimazole therapy spent &gt;90% of the study time in euthyroidism. Conclusions: In patients with Graves' hyperthyroidism, sustained normal serum TSH levels were more common in the long term as compared to the short-term methimazole treatment.

Relationship between thyroid function and sex hormones in female German shepherd dogs.

Several variables influence the serum concentration of thyroid hormones in dogs, including breed, age, drugs, and concurrent diseases. However, data regarding the interaction between thyroid function and the estrous stage of female dogs are limited. Estrous stage may influence thyroid function in German Shepherd dogs. Longitudinal, observational, non-randomized cohort study. The dogs were monitored during the complete estrous cycle, and different stages were determined by vaginal cytology. Two blood samples were collected at the beginning and end of each stage to analyze the following: total thyroxine (TT4), free thyroxine (fT4), total triiodothyronine (TT3), free triiodothyronine (fT3), canine thyrotropin (cTSH), progesterone, 17-β-estradiol, triglycerides, and cholesterol concentrations. Hematological and biochemical evaluations were performed at the beginning and end of the study period. Seventeen German Shepherds were included, of which 7 were bred during the study period. One dog was excluded for estrus interruption and another for suspected hypothyroidism. Serum concentrations of T4, fT4, and fT3 were negatively correlated with age. Total thyroxine demonstrated significant changes in serum concentrations between estrous stages, with higher concentrations in estrus and diestrus. Total thyroxine concentrations were positively correlated with progesterone concentrations and negatively correlated with 17-β-estradiol concentrations. Free thyroxine did not show significant variations but was positively correlated with progesterone concentrations. Canine TSH concentrations were positively correlated with 17-β-estradiol concentrations. No significant differences in thyroid hormones and cTSH concentrations were observed between diestrus during pregnancy and pseudopregnancy. Different stages of estrus can influence the measurement of TT4 in female dogs.

Serum steroid and thyroid hormone concentrations in healthy domestic male and female alpacas.

Alpacas are high quality fiber producing animals, kept for production purpose and as pets. Endocrine imbalances from adrenal glands, gonads, or thyroid gland may result in coat abnormalities in domestic animals and affect reproduction. Contrary to many domesticated animals, information on hormone concentrations in alpacas is scarce. The purpose of this study was to provide steroid and thyroid hormone values in domestic alpacas. Blood was collected from healthy male (35 intact, 2 castrated) and female (48 non-pregnant, 3 pregnant) alpacas from local farms in Tennessee. Adrenal, reproductive, and thyroid hormones were analyzed. There were no significant differences in median concentrations of progesterone, estradiol, thyroxine (T4), and triiodothyronine (T3) between intact male and female non-pregnant alpacas. Median concentrations of testosterone, androstenedione, 17-hydroxyprogesterone, and cortisol were significantly higher in intact male alpacas compared to female non-pregnant alpacas. This information provides adrenal, gonadal, and thyroid hormone concentrations in alpacas to help with diagnosis of endocrine disorders.

Effect of indoxyl sulfate on the morphology and function of the thyroid gland - ex vivo studies in rabbits.

Indoxyl sulfates are uremic indolic toxins known to participate in the pathogenesis of cardiovascular diseases during chronic kidney disease in humans and some animal species. However, nothing is known about the indoxyl sulfate effect on the thyroid gland which is especially responsible for the general organism metabolism. This study determines the morpho-functional status of the thyroid gland after exposure to indoxyl sulfate (10, 25, and 50 mM) with the use of an ex vivo system and rabbit (n=10) as an experimental model thyroid gland histology, immunoexpression of thyrotropin receptor (TSHR), and concentrations of thyroxine (T4) and triiodothyronine (T3) were evaluated. Statistical analyses were performed using one-way analysis of the variance (ANOVA) followed by Tukey's post hoc comparison test. Minor alterations in thyroid tissue structure e.g. very rare exfoliated epithelial cells, condensed colloid fluid, or slight loosening of the epithelium were found. In addition, modulated dose dependent-expression of TSHR (p<0.01, p<0.001) together with a decreased level of T4 and T3 (p<0.001, p<0.01) exception of an increased level of T4 after the middle dose of indoxyl sulfate were revealed. We report here, for the first time, that indoxyl sulfate affects the thyroid gland mainly at the molecular level. The rabbit thyroid gland ex vivo system seems to be suitable for further studies on the thyroid gland in health and disease. However, the effect of TSH-TSHR signaling at ultrastructural, and epigenetic levels needs supplementary appraisal.

Diabetes Modulates Iodothyronine Deiodinase 2 Expression in the Mouse Retina: A Role for Thyroid Hormone in the Pathogenesis of Diabetic Retinopathy.

Clinical investigations associate hypothyroidism with an increased risk for microvascular complications, yet the mechanism by which thyroid hormone regulates the development of diabetic retinopathy is not clearly understood. We investigated the role of iodothyronine deiodinase 2 (DIO2) in the pathogenesis of diabetic retinopathy. Retinas from streptozotocin-induced diabetic and nondiabetic mice were evaluated by RNA sequencing, RT-PCR, and immunostaining. Media and cell lysates from mouse retinal microvascular endothelial cells and retinal astrocytes exposed to physiologic (5mM) and high glucose (25 mM) containing media were assessed by liquid chromatography-tandem mass spectrometry to measure tetraiodothyronine (T4) and tri-iodothyronine (T3) concentrations and by Western blot analysis to determine the relationship of T4/T3 to oxidative stress and inflammatory mediators. Cell death was determined by Trypan Blue exclusion assay. At 12 weeks of diabetes duration, retinas from diabetic mice compared with nondiabetic mice demonstrated a significant decrease in Dio2 transcripts and Dio2 gene and protein (P < 0.05) expression. When cultured in the presence of high glucose, both mouse retinal astrocytes and microvascular endothelial cells demonstrated a significant reduction of DIO2 protein compared with cells cultured in physiologic glucose. High glucose inhibited generation of T3, leading to a significantly increased T4/T3 (P < 0.0079). Supplementation of cells with T3, but not T4, prevented the high glucose-induced rise in endothelial nitric oxide synthase, intercellular cell adhesion molecule 1, and endothelial cell death (P < 0.0079). Decreased intraretinal T3 owing to diabetes-induced loss of DIO2 may lead to dysfunction and death of cells in the retina, thereby contributing to the pathogenesis of early diabetic retinopathy.

Changes in thyroid function levels in female patients with first-episode bipolar disorder.

The identification of molecular biomarkers for bipolar disorder is anticipated to greatly improve the diagnosis and treatment of this disease. The objective of this case-control study is to determine whether the blood thyroid hormone levels in bipolar disorder patients are associated with different types of first onset. From August 1, 2020 to July 31, 2021 a total of 120 female patients diagnosed with bipolar disorder and hospitalized at Qingdao Mental Health Center were recruited as the case group, including 60 patients with depression as their first onset (depression first-episode group, DF) and 60 with mania/hypomania as their first onset (mania/hypomania first-episode group, M/HF). A group of 60 healthy adult females matching general demographic data, such as race and age, were selected as the control group. Blood samples were taken from both groups to measure serum triiodothyronine (T3), thyroxine (T4), free triiodothyronine (FT3), free thyroxine (FT4), and thyroid stimulating hormone (TSH) concentrations. The duration of current onset in the M/HF group was significantly less than that in the DF group (23.1 ± 20.2 vs. 125.2 ± 41.0 days). About 27% of patients in the M/HF group had thyroid abnormalities, in contrast to 60% in the DF group. The blood T3 and T4 levels in both the M/HF group and the DF group, as well as the TF3 levels in the DF group, were significantly lower as compared to control. The M/HF group had significantly higher T3 and FT3 levels than the DF group. The blood T3 levels were inversely correlated with the Young's Mania Scale score and the Hamilton Depression Scale score in both the M/HF and DF groups. Thyroid dysfunction resulting in reduced levels of blood thyroid levels may be involved in the disease progression of bipolar disorder, and correlated with the clinical symptoms in patients with depression or mania as the first episode.

Effects of genetic selection for fast growth on the development of wooden breast myopathy in broilers

ABSTRACT 1. This study investigated the physiological and molecular mechanisms leading to wooden breast (WB) by comparing growth parameters, oxygen consumption rate, thyroid hormone and gene expression patterns in fast- versus slow-growing broiler lines (Cobb500 and L1986, respectively). 2. WB was observed in Cobb500 broilers only and was first diagnosed on d 21 post-hatch. Compared to the slow-growing L1986, Cobb500 showed a significantly higher growth rate, relative breast weight, breast thickness, meat pH and water-retention capacity (drip loss). Correspondingly, there was significantly lower relative heart weight, relative right ventricular weight, triiodothyronine and thyroxine concentrations and oxygen consumption rate. 3. Compared to No-WB Cobb500, the WB-affected samples exhibited higher relative breast weight, breast thickness and drip loss and lower plasma total thyroxine (T4) concentrations. 4. Selection for fast growth was associated with differential expression of genes involved in hypoxia (PLOD2), energy metabolism (FABP3, FABP4, CD36, and LPL), endoplasmic reticulum stress, muscle regeneration (CSRP3) and fibre-type switching (ANKRD1). WB-affected samples exhibited an upregulation of CSRP3, PLOD2 and ANKRD1, while CD36 was downregulated. Taken together, selection for fast growth and muscle gain is not matched by adequate cardiac and metabolic support systems.

Hyperthyroidism: A Review.

Overt hyperthyroidism, defined as suppressed thyrotropin (previously thyroid-stimulating hormone) and high concentration of triiodothyronine (T3) and/or free thyroxine (FT4), affects approximately 0.2% to 1.4% of people worldwide. Subclinical hyperthyroidism, defined as low concentrations of thyrotropin and normal concentrations of T3 and FT4, affects approximately 0.7% to 1.4% of people worldwide. Untreated hyperthyroidism can cause cardiac arrhythmias, heart failure, osteoporosis, and adverse pregnancy outcomes. It may lead to unintentional weight loss and is associated with increased mortality. The most common cause of hyperthyroidism is Graves disease, with a global prevalence of 2% in women and 0.5% in men. Other causes of hyperthyroidism and thyrotoxicosis include toxic nodules and the thyrotoxic phase of thyroiditis. Common symptoms of thyrotoxicosis include anxiety, insomnia, palpitations, unintentional weight loss, diarrhea, and heat intolerance. Patients with Graves disease may have a diffusely enlarged thyroid gland, stare, or exophthalmos on examination. Patients with toxic nodules (ie, in which thyroid nodules develop autonomous function) may have symptoms from local compression of structures in the neck by the thyroid gland, such as dysphagia, orthopnea, or voice changes. Etiology can typically be established based on clinical presentation, thyroid function tests, and thyrotropin-receptor antibody status. Thyroid scintigraphy is recommended if thyroid nodules are present or the etiology is unclear. Thyrotoxicosis from thyroiditis may be observed if symptomatic or treated with supportive care. Treatment options for overt hyperthyroidism from autonomous thyroid nodules or Graves disease include antithyroid drugs, radioactive iodine ablation, and surgery. Treatment for subclinical hyperthyroidism is recommended for patients at highest risk of osteoporosis and cardiovascular disease, such as those older than 65 years or with persistent serum thyrotropin level less than 0.1 mIU/L. Hyperthyroidism affects 2.5% of adults worldwide and is associated with osteoporosis, heart disease, and increased mortality. First-line treatments are antithyroid drugs, thyroid surgery, and radioactive iodine treatment. Treatment choices should be individualized and patient centered.