Blood Hormone Concentrations Research Articles

The gut microbiome of kittens is affected by dietary protein: carbohydrate ratio and correlated with blood metabolite and hormone concentrations

This study was conducted to test the effects of dietary protein: carbohydrate ratio on the composition of the gut microbiota using 454 pyrosequencing and identify associations with blood metabolites of growing kittens. Male domestic shorthair kittens were raised by mothers fed moderate‐protein, moderate‐carbohydrate (MPMC; n=7) or high‐protein, low‐carbohydrate (HPLC; n=7) diets. Fasted blood samples were collected and analyzed for blood metabolites and hormones. Pyrosequencing resulted in a total of 384,588 sequences, with an average of 9,374 sequences per sample. A dual hierarchical clustering dendogram of the most abundant bacterial genera indicated distinct clustering of samples based on protein:carbohydrate ratio. The principal component analysis of fecal bacterial families, blood metabolites, and hormones resulted in 4 distinct clusters. One cluster included blood triglycerides and fecal Clostridiaceae, Eubacteriaceae, Ruminococcaceae, Fusobacteriaceae, and Lachnospiraceae. A second cluster consisted of blood ghrelin and fecal Coriobacteriaceae, Bifidobacteriaceae, and Veillonellaceae. A third cluster consisted of blood glucose, cholesterol, and leptin and fecal Lactobacillaceae. The strong correlations between blood hormones and metabolites and well‐known probiotic bacterial families indicate potential significance as it pertains to satiety and host metabolism.Grant Funding Source : United States Department of Agriculture‐Cooperative State Research, Education and Extension Service (project ILLU‐538‐396)

Multilevel regulation of steroid synthesis and metabolism in the bovine placenta

Steroid hormones play critical roles in almost all physiological processes in male and female reproduction. In a normal pregnancy, the concentrations of steroid hormones in maternal and foetal blood vary with gestation in response to changing needs. The placenta plays a central role in producing the appropriate steroids to support the pregnancy by coordinating its own steroidogenic activity with that of the corpus luteum and responding to foetal signals. Although much is known about the steroidogenic potential of the bovine placenta, far less is known about how the placenta integrates the synthesis of steroids with their subsequent metabolism and clearance to achieve appropriate local and peripheral concentrations of steroids in maternal and foetal blood at each stage of gestation. This review focuses on the current knowledge of the temporal and spatial regulation and compartmentalization of the biochemical pathways by which potent steroid hormones are synthesized and metabolized in the bovine placenta. The aim is to increase our understanding of how the balance of synthesis and metabolism determines placental steroid output as it changes with development and differentiation, and how this is regulated in response to the variations in the foetal signals and luteal secretory activity. The review highlights knowledge gaps and suggests that mathematical modelling can help understand the effect of different levels of regulation on the steroidogenic output of an organ, such as the bovine placenta.

Determination of anti-Müllerian hormone concentrations in blood as a tool to select Holstein donor cows for embryo production: from the laboratory to the farm

High between-animal variability in the number of embryos produced by multiple ovulation and embryo transfer (MOET) and ovum pick-up and in vitro production (OPU-IVP) methods remains a major limit to the development of embryo biotechnologies in cattle. The measurement of anti-Müllerian hormone (AMH) endocrine concentrations in cows can help to predict their follicular and ovulatory responses to gonadotrophin treatment. The present study aimed to provide practical information for a simple prognostic method based on AMH measurement in Holstein cows. Accurate AMH concentrations could be measured with ELISA in blood or plasma. In cows undergoing repeated OPU protocols over 1 year, the AMH concentrations measured in plasma samples collected before each gonadotrophin treatment were found to be highly repeatable and were tightly correlated with follicular responses. From data obtained at both an experimental station and farm settings, it was possible to propose AMH cut-off values to identify low-responding cows. Gonadotrophin-stimulated cows producing fewer than 15 large follicles at oestrus and fewer than 10 embryos in MOET protocols could be discarded efficiently with plasma AMH concentrations below 87 and 74 pg mL(-1), respectively. In conclusion, we propose a prognostic method based on a single AMH measurement to improve the results of embryo biotechnologies.

The effects of glutamine supplementation on performance and hormonal responses in non-athlete male students during eight week resistance training

Hakimi M, Mohamadi MA, Ghaderi Z. The effects of glutamine supplementation on performance and hormonal responses in non-athlete male students during eight week resistance training. J. Hum. Sport Exerc. Vol. 7, No. 4, pp.770-782, 2012. The aim of this study was to determine the effects of glutamine supplementation on performance, and hormonal changes during an 8-week resistance training program in non athlete male students. Thirty healthy non athlete male (age 21.25 ± 1.6 years, height 173.2 ± 3.2 cm, body mass 72.8 ± 2.8 kg, VO2max 43.48± 2.38 ml·kg -1 ·min -1 ) were randomly divided into a glutamine supplementation (GL) group (n=15), and a placebo (PL) group (n=15). Each group was given either glutamine or a placebo in a double blind manner to be taken orally for eight weeks (0.35 g/kg/day). GL and PL groups performed the same weight training program 3 days, each week for 8 weeks. The training consisted of 3 sets of 8 repetitions, and the initial weight was 80% of the pre-1RM. Subjects were tested for performance and blood hormone concentrations before and after the 8-week period. Both groups increased their performance however the GL group showed significantly greater increases in upper and lower body strength, explosive muscular power, blood testosterone, GH and IGF-1 when compared to the PL group; however, cortisol concentrations were significantly more reduced in GL group when compared to the PL group. It can, therefore, be concluded that within 8 weeks glutamine supplementation during resistance training was found to increase performance (explosive muscular power, muscle strength) and improved

Interpretation of Hormone Levels in Older Patients: Points for Consideration

Blood hormone and tumor marker concentrations are usually determined by immunochemical methods which are based on an unique reaction between antigen and assay capture antibody. Despite the speed and simplicity of assays performance on automatic immunochemistry platforms, the interpretation of final results requires a deep knowledge of method fallibility. General lack of immunoassays standardization, presence of cross-reacting substances in patient's sample, limitation of free hormones measurement due to abnormal analyte binding protein concentrations, assay interferences due to patient's autoantibodies, and heterophilic antibodies, as well as proper interpretation of very low- and very high-sample analyte levels, are the main points discussed in respect to hormones and tumor markers measurement in geriatric population.

Steroid profiling by gas chromatography-mass spectrometry and high performance liquid chromatography-mass spectrometry for adrenal diseases.

The ability to measure steroid hormone concentrations in blood and urine specimens is central to the diagnosis and proper treatment of adrenal diseases. The traditional approach has been to assay each steroid hormone, precursor, or metabolite using individual aliquots of serum, each with a separate immunoassay. For complex diseases, such as congenital adrenal hyperplasia and adrenocortical cancer, in which the assay of several steroids is essential for management, this approach is time consuming and costly, in addition to using large amounts of serum. Gas chromatography/mass spectrometry profiling of steroid metabolites in urine has been employed for many years but only in a small number of specialized laboratories and suffers from slow throughput. The advent of commercial high-performance liquid chromatography instruments coupled to tandem mass spectrometers offers the potential for medium- to high-throughput profiling of serum steroids using small quantities of sample. Here, we review the physical principles of mass spectrometry, the instrumentation used for these techniques, the terminology used in this field and applications to steroid analysis.

PHYSIOLOGY AND ENDOCRINOLOGY SYMPOSIUM: Harnessing basic knowledge of factors controlling puberty to improve synchronization of estrus and fertility in heifers1

The development of replacement heifers is a major economic investment for all beef and dairy operations. The costs associated with heifer development cannot be recovered if heifers do not conceive and remain productive in the herd; therefore, heifers need to conceive early in the breeding season or risk being culled. Previous research has reported up to a 21% increase in fertility from pubertal estrus to the third estrus of a heifer. The use of reproductive tract scores to determine pubertal status has demonstrated that peripubertal and pubertal heifers have increased pregnancy success to estrous synchronization compared with heifers that were prepubertal. The development of RIA has allowed accurate measurement of peripheral blood hormone concentrations associated with the pubertal process and luteal formation. This basic knowledge has increased our understanding of the mechanisms that control puberty in heifers. In addition, understanding the hormonal changes that occur during the estrous cycle has allowed for the development of estrous synchronization protocols that result in increased control of follicular growth, regression of luteal tissue, and ovulation. Transrectal ultrasonography has increased our understanding of follicular waves; this understanding led to research investigating the endocrine regulation of follicular waves and development of methods to synchronize follicular waves for purposes of fixed-time AI. Current topics of research include the effect of antral follicle count on fertility and the effect of maternal nutrition (on the fetus in utero) on subsequent reproductive potential of a heifer (i.e., fetal programming). Advancements in genomic technologies will likely provide a powerful tool for selecting heifers at birth that will have a greater probability of being reproductively successful if managed correctly. Therefore, knowledge gained through basic research on factors that control puberty has improved and will continue to improve heifer development and fertility.

Trans-Placental Transfer of Thirteen Perfluorinated Compounds and Relations with Fetal Thyroid Hormones

While the results of animal studies have shown that perfluorinated compounds (PFCs) can modulate concentrations of thyroid hormones in blood, limited information is available on relationships between concentrations of PFCs in human blood serum and fetal thyroid hormones. The relationship between concentrations of PFCs in blood and fetal thyroid hormone concentrations or birth weight, and ratios of major PFCs between maternal and fetal serum were determined. Concentrations of PFCs were measured in blood serum of pregnant women (n = 44), fetal cord blood serum (n = 43) and breast milk (n = 35). Total concentrations of thyroxin (T4), triiodothyronin (T3) and thyroid stimulating hormone (TSH) in blood serum were also quantified. The ratios of major PFCs in maternal versus fetal serum were 1:1.93, 1.02, 0.72, and 0.48 for perfluorotridecanoic acid (PFTrDA), perfluorooctanoic acid (PFOA), perfluorohexane sulfonate (PFHxS), and perfluorooctane sulfonate (PFOS), respectively. Fetal PFOS, PFOA, PFTrDA and maternal PFTrDA were correlated with fetal total T4 concentrations, but after adjusting for major covariates, most of the relationships were no longer statistically significant. However, the significant negative correlations between maternal PFOS and fetal T3, and maternal PFTrDA and fetal T4 and T3 remained. Since thyroid hormones are crucial in the early development of the fetus, its clinical implication should be evaluated. Given the observed trans-placental transfer of PFCs, efforts should be also made to elucidate the exposure sources among pregnant women.

Postprandial changes in plasma acylcarnitine concentrations as markers of fatty acid flux in overweight and obesity

This study determined whether reductions in postprandial plasma nonesterified fatty acid (FFA) flux would lead to reductions in plasma acylcarnitine (AC) concentrations. Plasma AC was measured by liquid chromatography with tandem mass spectrometry in the fasting state and over 6 hours after a high-fat (50% energy) meal was fed to 16 overweight and obese subjects with a wide range of insulin sensitivities. Body composition was measured by dual-energy x-ray absorptiometry; insulin sensitivity by insulin-modified, frequently sampled intravenous glucose tolerance test; substrate oxidation by indirect calorimetry; blood metabolite and hormone concentrations biochemically; and fatty acid flux by using stable isotope tracers. Lean body mass and fasting fat oxidation correlated positively ( r > 0.522, P < .05), whereas glucose oxidation correlated negatively ( r < −0.551, P < .04), with fasting AC. Postprandially, plasma glucose, insulin, and triglyceride concentrations increased; and FFA concentrations decreased significantly. The responses of plasma AC species depended on chain length and saturation, with C14:0, C16:0, and C18:0 remaining unchanged, and unsaturated species (eg, C14:1, C14:2) falling significantly (21%-46%, P < .03). Postmeal nadir AC concentrations were positively associated with lean body mass, postprandial fatty acid flux, and FFA concentrations ( r > 0.515, P < .05). By contrast, nadir AC correlated negatively with insulin sensitivity and spillover of meal-derived fatty acids ( r < −0.528, P < .04). Conditions that impact fatty acid flux contribute to the control of postprandial plasma AC concentrations. These data underscore the need for a better understanding of postprandial fatty acid oxidation and dietary fat delivery in the setting of adipose insulin resistance to determine how postprandial lipemia contributes to chronic disease risk.

CANCER PATIENTS THYROID AND GLUCOCORTICOID HOMEOSTASIS IN METASTATIC BRAIN DISEASE

Blood concentration of hormones – stress indicators has been studied in patients with metastatic brain disease at pretreatment stage. Pronounced deviations of glucocorticoid and thyroid homeostasis have been observed in these patients. Dependence of hormonal parameters dynamics on extension of cerebral and extracranial metastasizing has been revealed.

The Effects of Whey Protein Supplementation on Performance and Hormonal Adaptations Following Resistance Training in Novice Men

The purpose of this study was to determine the effects of whey protein supplementation on performance and hormonal changes during an 8-week resistance training program in novice weight trained men. Forty recreational weight trained men were randomly divided into a whey protein supplementation (WP) group (n=20), and a placebo (PL) group (n=20). Each group was given either whey protein or a pla cebo in a double-blind manner to be taken orally for eight weeks (1.8 g/kg/day). WP and PL groups performed the same weight training program 3 days, each week for 8 weeks. The training consisted of 3 sets of 8 repetitions, and the initial weight was 80% of the pre-1RM. Sub jects were tested for performance and blood hormone concentrations before and after the 8-week period. The WP group achieved greater increases in body weight, explosive muscular power, muscle strength and blood testosterone when compared to the PL group; however, cortisol concentrations were significantly more reduced in WP group when compared to the PL group. It can, therefore, be concluded that within 8 weeks whey protein supplementation was found to increase explosive muscular power, body weight and muscle strength.

Acute and cumulative effects of focused high-frequency vibrations on the endocrine system and muscle strength

The purpose of this study was to evaluate the acute and long-term effects of local high-intensity vibration (HLV, f = 300 Hz) on muscle performance and blood hormone concentrations in healthy young men. Totally 18 subjects (cV group) were studied in two sessions, either without (control) or with HLV treatment. The protocol was the same on both control and test days, except that, in the second session, subjects underwent HLV treatment. Counter-movement jumping (CMJ), maximal isometric voluntary contraction (MVC) test, and hormonal levels were measured before the procedure, immediately thereafter, and 1 h later. To assess the long-term effects of HLV, the cV group was subjected to HLV on the leg muscles for 4 weeks, and a second group (cR group, n = 18) embarked upon a resistance training program. All subjects underwent an MVC test and an isokinetic (100 deg/s) test before training, 4 weeks after training, and 2 months after the end of training. The HLV protocol significantly increased the serum level of growth hormone (GH, P < 0.05) and creatine phosphokinase (CPK, P < 0.05), and decreased the level of cortisol (P < 0.05). None of GH, CPK or testosterone levels were altered in controls. There was a significant improvement in MVC (P < 0.05). After 4 weeks, both the cV and cR groups demonstrated significant improvement in MVC and isokinetic tests (P < 0.05). This increase persisted for at least 2 months. Our results indicate that HLV influences the levels of particular hormones and improves neuromuscular performance. Our results indicate that HLV has a long-term beneficial effect comparable to that of resistance training.

The effects of creatine supplementation on sprint running performance and selected hormonal responses

The purpose of this study was to determine the influence of short-term creatine supplementation on sprint running performance (100 and 200 m) and circulating hormone [growth hormone (GH), testosterone and cortisol] concentrations. Twenty amateur male runners were randomly divided into a creatine supplementation group, or placebo group. Subjects were provided with capsules containing either creatine monohydrate or identical powdered cellulose placebo. Daily creatine monohydrate supplementation was 20 g/day parceled into three equal dosages to be consumed with each major meal. Subjects were tested for performance and resting blood hormone concentrations before and after six days. A double-blind research design was employed in this study. After this creatine loading, the mean running performance time of the creatine supplementation group decreased significantly in the 100 m, but not the 200 m. Serum GH, testosterone, and cortisol concentrations were not affected by creatine supplementation. It can therefore be concluded that although short-term creatine supplementation was found to improve sprint performance in the 100 m in amateur runners, this performance improvement did not appear to be hormonally mediated.Key words: Sprint performance; Creatine supplementation; Hormonal responses; Creatine loading.

Greater milk yield is related to increased DNA and RNA content but not to mRNA abundance of selected genes in sow mammary tissue

The relationship between greater sow milk yield and mammary development, expression of selected genes in mammary tissue and hormonal concentrations in lactating sows was studied. Crossbred sows were separated in two groups according to the weight gains of their piglets up to day 21. The groups were: (1) lower milk yield (LOW, n = 14) and (2) higher milk yield (HI, n = 14), representing lactation weight gains of 4.46 and 5.25 kg pig-1, respectively. Jugular blood samples were obtained from all sows on day 3 (for prolactin determination) and day 23 (for measures of prolactin, leptin, insulin, glucose and free fatty acids) of lactation, and milk samples were collected on days 3 and 22. At weaning (day 23), sows were slaughtered and their mammary glands were collected, dissected and composition was determined. Mammary parenchymal tissue was analyzed for the mRNA abundance of selected genes. Hormone concentrations in blood did not differ between groups (P &gt; 0.1) and on day 3 of lactation, dry matter and leptin contents in milk were lower (P &lt; 0.05) in HI than in LOW sows. There was more DNA and RNA per teat in HI than LOW sows (P &lt; 0.05), whereas the expression of selected genes within mammary tissue was unaffected (P &gt; 0.1) by production group. Significant correlations (P &lt; 0.01) existed between average weight gain of piglets during lactation and mammary RNA and DNA, expressed either as total amount or amount per teat, at weaning. Sow milk yield is therefore related to mammary gland composition in late lactation.Key words: Genes, lactation, mammary gland, milk yield, sow

Association of Season and Pasture Grazing with Blood Hormone and Metabolite Concentrations in Horses with Presumed Pituitary Pars Intermedia Dysfunction

Pituitary pars intermedia dysfunction (PPID) is a risk factor for pasture-associated laminitis, which follows a seasonal pattern. Hormonal responses to season differ between PPID and unaffected horses. Seventeen horses aged 8-30 years (14 horses ≥ 20 years of age). Longitudinal observational study. Blood was collected monthly from August 2007 until July 2008 after pasture grazing and again after overnight stall confinement. Blood hormone and metabolite concentrations were measured and pasture grass samples were analyzed to determine carbohydrate content. Analysis of variance analysis for repeated measures was performed. Mean ACTH concentrations varied significantly over time (P < .001), with higher concentrations detected in August, September, and October compared with November-April. Pasture × time effects were detected for glucose and insulin concentrations, with peaks observed in September. Horses were retrospectively allocated to PPID (n = 8) and control (n = 9) groups on the basis of plasma ACTH concentrations. Changes in insulin concentrations over time differed in the PPID group when compared with the control group. Insulin concentrations were positively correlated with grass carbohydrate composition. PPID did not affect the timing or duration of the seasonal increase in ACTH concentrations, but higher values were detected in affected horses. Insulin concentrations differed between groups, but hyperinsulinemia was rarely detected. Glucose and insulin concentrations peaked in September when horses were grazing on pasture, which could be relevant to the seasonal pattern of laminitis.

Reversible escitalopram-induced hypothyroidism

Some drugs can cause alterations in the concentration of thyroid hormones in blood even without clinical signs of dysfunction or pathology of the thyroid gland. Apart from the well-known relationship between depression and hypothalamic-pituitary-thyroid (HPT) axis, and the impact of selective serotonin reuptake inhibitors (SSRIs) on thyroid indices, hypothyroidism is a very rare adverse effect of SSRI treatment. However, the case presented here demonstrates that escitalopram may have the potential to induce hypothyroidism without any significant clinical signs and symptoms. Therefore, the possibility of SSRI-induced asymptomatic hypothyroidism presented here may help clinicians in this regard.

Weight-of-evidence analysis of human exposures to dioxins and dioxin-like compounds and associations with thyroid hormone levels during early development

Thyroid hormones play a critical role in the proper development of brain function and cell growth. Several epidemiological studies have been conducted to assess potential associations between pre- and post-natal exposure to dioxins or dioxin-like compounds (DLCs) and the levels of circulating thyroid hormones during early development. Dioxins and DLCs include chlorinated dibenzo- p-dioxins, chlorinated dibenzofurans, and mono- and non- ortho polychlorinated biphenyls (PCBs). We identified a total of 23 relevant epidemiological studies (21 cohort studies and 1 case–control study) that measured exposures to various types of dioxins and DLCs as well as markers of thyroid function, such as thyroid stimulating hormone (TSH), total thyroxine (T4), free T4, total triiodothyroxine (T3), free T3, and thyroid-binding globulin concentrations in cord blood or circulation. While some of the studies reported associations between concentrations of dioxins and/or DLCs and some biomarkers of thyroid function, the majority of the observed associations were not statistically significant. Moreover, there were no clear and consistent effects across studies for any of the hormone levels examined, and while a number of studies showed a statistically significant association with exposure for a given marker of thyroid function, other studies showed either no change or changes in the opposite direction for the same thyroid function marker. Similarly, when the results were analyzed considering developmental stage, there generally were no clear and consistent effects at any age from birth through 12 years of age. The absence of a clear correlation between background exposures to dioxins and DLCs and thyroid function biomarkers during development is not consistent with the hypothesis that background exposures to these chemicals cause effects on thyroid function during development.

Bayesian Hierarchical Analysis for Multiple Health Endpoints in a Toxicity Study

Bayesian hierarchical models are built to fit multiple health endpoints from a dose-response study of a chemical contaminant, perchlorate. Perchlorate exposure results in iodine uptake inhibition in the thyroid, with health effects manifested by changes in blood hormone concentrations and histopathological effects on the thyroid. We propose empirical models to fit blood hormone concentration and thyroid histopathology data for rats exposed to perchlorate in the 90-day study of Springborn Laboratories Inc. (1998), based upon a mechanistic model derived from the assumed toxicological relationships between dose and the various endpoints. All of the models are fit in a Bayesian framework, and predictions about each endpoint in response to dose are simulated based on the posterior predictive distribution. A hierarchical model tries to exploit possible similarities between different combinations of sex and exposure duration, and it allows us to produce more stable estimates of dose-response curves. We also illustrate how the Bayesian model specification allows us to address additional questions that arise after the analysis.

Effects of aging on body temperature and several hormones (ADH, TSH, fT3, fT4 and leptin) in different seasons

With change in the season, the patterns of body temperature regulation as well as hormonal regulation might be modified. The purpose of this study is to examine the seasonal changes in various hormones in association with temperature and metabolic regulation (ADH, TSH, fT3, fT4 and leptin) in young (21±1 yrs; mean±SD) and elder subjects (69±5 yrs; mean±SD). At each season, blood was taken in a sitting position at rest after the subject stayed for 30 min or more in the climatic chamber set at 26°C and 50%RH, and the blood osmolality and hormone concentrations were measured. The average of atmospheric temperature in experimental days were 15‐20°C in spring, 25‐30°C in summer, 15‐23°C in autumn and 5‐10°C in winter. We found that: 1) ADH concentration was significantly higher in elder than in younger in winter; 2) osmolality in elder subject was significantly higher in winter than in summer; 3) concentration of leptin in elder subjects was significantly higher in winter than in other seasons; 4) concentration of TSH, fT3 and fT4 in elder subjects was not significantly different with seasons. It was suggested that hormonal regulation was reduced in elder subjects in winter.

CHARACTERISTIC OF METABOLISM-REGULATING HORMONES CONCENTRATION CHANGE in POSTMORTAL AND ALIVE BLOOD DEPENDING ON ETHYL ALCOHOL LEVEL

Distinctions in concentration of blood serum hormones in postmortem blood and persons are established at various concentration of ethyl alcohol. The revealed changes can be caused by the processes occurring in the postmortal period (raised cytolysis, damages of the receptors, increased protein catabolism, change of water and cells of blood ratio, etc.). The most stable molecules are steroid structures (cortisol). For definition of pancreas function it is recommended to determine a level of C-peptide and proinsulin as more stable protein molecules.