Reproductive Hormone Concentrations Research Articles

Knockdown of Ptprn-2 delays the onset of puberty in female rats

In the present study, we evaluated how Ptprn-2 (encoding tyrosine phosphatase, receptor type, N2 polypeptide protein) affects the onset of puberty in female rats. We evaluated the expression of Ptprn-2 mRNA and protein in the hypothalamus-pituitary-ovary axis of female rats using real-time quantitative reverse transcription polymerase chain reaction (RT-qPCR) and immunofluorescence at infancy, prepuberty, puberty, peripuberty, and adulthood. We evaluated the effects of Ptprn-2 gene knockdown on different aspects of reproduction-related biology in female rats, including the expression levels of puberty-related genes in vivo and in vitro, the time to onset of puberty, the concentration of serum reproductive hormones, the morphology of ovaries, and the ultrastructure of pituitary gonadotropin cells. Our results demonstrated that PTPRN-2 was primarily distributed in the arcuate nucleus (ARC), periventricular nucleus (PeN), adenohypophysis, and the ovarian follicular theca, stroma, and granulosa cells of female rats at various stages. Ptprn-2 mRNA levels significantly varied between peripuberty and puberty (P < 0.05) in the hypothalamus and pituitary gland. In hypothalamic cells, Ptprn-2 knockdown decreased the expression of Ptprn-2 and Rfrp-3 mRNA (P < 0.05) and increased the levels of Gnrh and Kiss-1 mRNA (P < 0.05). Ptprn-2 knockdown in the hypothalamus resulted in delayed vaginal opening compared to the control group (n = 12, P < 0.01), and Ptprn-2, Gnrh, and Kiss-1 mRNA levels (P < 0.05) all decreased, while the expression of Igf-1 (P < 0.05) and Rfrp-3 mRNA (P < 0.01) increased. The concentrations of FSH and P4 in the serum of Ptprn-2 knockdown rats were lower than in control animals (P < 0.05). Large transverse perimeters and longitudinal perimeters (P < 0.05) were found in the ovaries of Ptprn-2 knockdown rats. There were fewer large secretory particles from gonadotropin cells in adenohypophysis tissue of the Ptprn-2 knockdown group compared to the control group. This indicates that Ptprn-2 knockdown can regulate levels of Gnrh, Kiss-1, and Rfrp-3 mRNA in the hypothalamus, regulate the concentration of serum FSH and P4, and alter the morphology of ovarian and gonadotropin cells, delaying the onset of puberty in female rats.

Filling in the holes: The reproductive biology of the understudied Mahali mole-rat (Cryptomys hottentotus mahali)

African mole-rats have provided great insight into mammalian evolution of sociality and reproductive strategy. However, some species have not received attention, and these may provide further insights into these evolutionary questions. The cooperatively breeding Mahali mole-rat (Cryptomys hottentotus mahali (Roberts, 1913)) is one such species. Body mass, reproductive-tract morphometrics, gonad histology, and plasma reproductive hormone concentrations were studied for breeding and non-breeding males and females over 1 year. This study aimed to discern if this species exhibits a seasonal or aseasonal breeding pattern and whether there is a relaxation of reproductive suppression at any point in the year in non-breeding animals. The pattern of reproductive relaxation during the wetter months is similar to other African mole-rat species. Interestingly, births and pregnant breeding females were recorded throughout the year, thus indicating an aseasonal breeding strategy, despite inhabiting a region that experiences seasonal rainfall. However, there were periods of the year favouring increased reproduction to enable an increased likelihood of offspring survival. This suggests that the Mahali mole-rat may be an opportunistic breeder possibly brought about by the benefits of living in a cooperatively breeding group and potentially moving into more arid environments that were previously unexploited by the genus Cryptomys Gray, 1864.

English

BACKGROUND Infertility is the inability to become a parent of a child even after one year of intercourse involving male and female partner without any contraceptives. There are many causes for infertility, Y chromosome microdeletion is one among that. Partial or complete deletion of the proximal Yq region, which contains azoospermic factor (AZF) locus, leads to infertility. Along with genetic and biochemical factors the ethno-geographical reasons also play an important role in infertility. The present study was done to identify the association of genetic and hormonal factors in the development of infertility in azoospermic males of southern Kerala. METHODS Retrospectively screened the medical records of 2100 infertile males of the Department of Reproductive Medicine of Sree Avittom Tirunal Hospital, Government Medical College, Thiruvananthapuram for a period from January 2017 to December 2019. Stringent inclusion criterias were taken to select patients for the molecular study and finally 46 were selected. Structural and numerical chromosome abnormalities were detected using karyotyping and microdeletion was identified using polymerase chain reaction. Electro-chemiluminescence immunoassay method was used for the quantification of reproductive hormones. Demographic data of selected patients were collected from the medical records. RESULTS The cytogenetic results showed that among the selected patients, 10.86 % had Klinefelter syndrome and one person had De la Chapelle syndrome. Partial microdeletion in AZFa, b or c regions have been observed in 13.63 % of the patients. The hormonal analysis showed significant change in concentration of reproductive hormones irrespective of genetic defects. Demographic data showed that the majority of participated patients are unskilled/skilled laborers, economically poor and are from urban areas. CONCLUSIONS The study concludes that among the selected patients, 24.49 % have clinically significant chromosomal abnormalities like Klinefelter syndrome, De la Chappelle syndrome and partial microdeletion on the AZF region. Irrespective of genetic defects, significant changes in the concentration of reproductive hormones are also observed. KEYWORDS Azoospermia, Infertility, Karyotyping, Y Chromosome Microdeletion

Species validation, growth, reproduction and nutritional perspective of Indian pompano, Trachinotus mookalee–A candidate species for diversification in coastal mariculture

The Indian pompano Trachinotus mookalee can be an ideal and alternative marine candidate species for aquaculture with its cultivable traits. The study aimed to understand growth, reproductive and nutritional potentials of the fish in different culture environments and also for species validation to avoid ambiguities in further research. Wild collected broodfishes have confirmed that the species is genetically and morphologically differentiated from its four closely related species of genus Trachinotus. The studied fish growth was significantly (P < 0.05) influenced by culture environments, where the maximum growth was attained in cage (684.9 ± 14.0 g), followed by pond (564 ± 13.6 g), Recirculating Aquaculture System (RAS) (471.5 ± 10 g) and the least in indoor Fibre-reinforced plastic tank (294.65 ± 10.35 g) for 12 months of culture. Growth data indicated presence of high genetic growth potential in the species, which could be improved with suitable intervention in abiotic factors. Studied reproductive sex steroid hormone concentrations varied in the fish and were matched with the different maturity stages confirmed by gonadal development stages. The sexually mature male and female fish found with elevated levels of testosterone (2.34 ± 0.25 ng/ml) and 17-β estradiol (2.56 ± 0.95 ng/ml), respectively, which indicated that sex differences has been persisting in the species and the steroid level could act as marker in assessing the maturity status of male and female fish. The gonadal developmental stages indicated that the fish became functional male and female brooders after 26 and 29 months of culture in sea cages, respectively. Nutritional contents of the fish was significantly (P < 0.05) influenced by the culture environments. Crude protein was maximum in cage reared fish (18.96 ± 0.36%), whereas fish in RAS exhibited high crude fat (6.87 ± 1.05%). Palmitic (C16:0) and glutamic acids were the maximum abundant fatty acid and amino acid, respectively in all the cultured environments. However, the content of essential polyunsaturated fatty acids (DHA and EPA) was significantly high in wild fish. Phosphorus and iron were the maximum abundant major and micro minerals, respectively in all the culture systems. With excellent traits linked with aquaculture, the species could be the most suitable candidate for species diversification in coastal mariculture. The species deserves further studies on the basis of influence of abiotic factors on different traits.

Effect of plane of nutrition during the first 12 weeks of life on growth, metabolic and reproductive hormone concentrations, and testicular relative mRNA abundance in preweaned Holstein Friesian bull calves.

The objective of this study was to examine the effect of nutrition during the first 12 wk of life on aspects of the physiological and transcriptional regulation of testicular and overall sexual development in the bull calf. Holstein Friesian bull calves with a mean (SD) age and bodyweight of 17.5 (2.85) d and 48.8 (5.30) kg, respectively, were assigned to either a high (HI; n = 15) or moderate (MOD; n = 15) plane of nutrition and were individually fed milk replacer and concentrate to achieve overall target growth rates of at least 1.0 and 0.5 kg/d, respectively. Throughout the trial, animal growth performance, feed intake, and systemic concentrations of metabolites, metabolic hormones, and reproductive hormones were assessed. Additionally, pulsatility of reproductive hormones (luteinizing hormone, follicle-stimulating hormone, and testosterone) was recorded at 15-min intervals during a 10-h period at 10 wk of age. At 87 ± 2.14 d of age, all calves were euthanized, testes were weighed, and testicular tissue was harvested. Differential expression of messenger ribonucleic acid (mRNA) candidate genes involved in testicular development was examined using quantitative polymerase chain reaction assays. All data were analyzed using the MIXED procedure in Statistical Analysis Software using terms for treatment as well as time for repeated measures. Blood metabolites and metabolic hormones generally reflected the improved metabolic status of the calves on the HI plane of nutrition though the concentrations of reproductive hormones were not affected by diet. Calves on the HI diet had greater mean (SED) slaughter weight (112.4 vs. 87.70 [2.98] kg; P < 0.0001) and testicular tissue weight (29.2 vs. 20.1 [2.21] g; P = 0.0003) than those on the MOD diet. Relative mRNA abundance data indicated advanced testicular development through upregulation of genes involved in cellular metabolism (SIRT1; P = 0.0282), cholesterol biosynthesis (EBP; P = 0.007), testicular function (INSL3; P = 0.0077), and Sertoli cell development (CLDN11; P = 0.0054) in HI compared with MOD calves. In conclusion, results demonstrate that offering dairy-bred male calves a high plane of nutrition during the first 3 mo of life not only improves growth performance and metabolic status but also advances testicular development consistent with more precocious sexual maturation.

Diurnal variation in serum concentrations of cortisol in captive African (Loxodonta africana) and Asian (Elephas maximus) elephants.

Cortisol is involved in a broad range of physiological processes and enables animals to adapt to new situations and challenges. Diurnal fluctuations in circulating cortisol concentrations in elephants have been demonstrated based on samples from urine and saliva. The aims of this study were to demonstrate diurnal cortisol fluctuations based on blood samples and compare concentrations between seasons, species, and changes in reproductive hormone concentrations. Nine African (Loxodonta africana) and three Asian (Elephas maximus) elephants at two facilities in the United Stateswere included in this study. Blood samples were collected every 2-3 h at one location and every 1-6 h at another. Peak serum concentrations of cortisol averaged 28 ng/ml for both African and Asian elephants, and diurnal cycles included a fivefold decrease from morning peak to evening nadir concentrations. Diurnal cortisol profiles varied uniquely among individual elephants. During the winter, nadir concentrations of cortisol were slightly higher, and the timing of peak concentrations was less predictable. There was no correlation between diurnal serum concentrations of progesterone and cortisol; however, a significant correlation (p = .02) was identified between serum concentrations of testosterone and cortisol when a time lag of ~2-3 h was considered. The physiological significance of the positive correlations between diurnal serum concentrations of cortisol and testosterone in male elephants remains to be determined. If cortisol concentrations are being used to evaluate elephant health or welfare, samples should be obtained at the same time each day to minimize variation due to diurnal fluctuations, and ideally seasonal variations and individuality in diurnal profiles should also be considered.

Association between the Area of the Highest Flank Temperature and Concentrations of Reproductive Hormones during Pregnancy in Polish Konik Horses-A Preliminary Study.

Simple SummaryThermographic imaging is a potentially useful tool in pregnancy detection in equids, especially native or wildlife breeds. In late gestation, the differences in temperature of the flank area between pregnant and non-pregnant mares were suspected to be caused by hormonal effects on regional blood flow. This preliminary study aimed to assess changes in thermal features of the abdomen lateral surface and concentrations of reproductive hormones in Polish native pregnant mares. The study was carried out on pregnant and non-pregnant Polish native Konik Polski mares, and both the hormonal profile and the thermal pattern of mares’ abdomens were examined monthly. The features from thermal images in rainbow HC and gray palette were extracted to determine relations with a hormonal profile dependent across the months of pregnancy. The new feature of a thermal image in the gray palette, the area with the highest temperatures (Area of Tmax), was found to be significantly related to progesterone and relaxin blood concentration. The standard features of the thermal image did not show any similar associations over consecutive months of pregnancy. In this preliminary study, a new approach to thermographic imaging analysis based on the Area of Tmax calculation was proposed. However, further research is needed to better understand the relation between the Area of Tmax and concentrations of reproductive hormones, especially including an experiment with at least daily blood sampling and the hair coat lengths examination.Determination of the pregnancy status is one of the most important factors for effective pregnancy management. Knowledge of the stage of pregnancy is important to interpret many of the reproductive hormones’ concentrations, including progesterone (P4), estrone sulfate (E1S), 17-ß estradiol (E2), and relaxin (REL). However, it is limited in wildlife or captive equids that cannot be handled. Reproductive hormones affect regional blood flow, the proliferation of tissues, and local metabolism intensity. Therefore, this preliminary study aimed to assess changes in thermal features of the abdomen lateral surface and concentrations of reproductive hormones in Polish native pregnant mares. The study was carried out on 14 non-pregnant and 26 pregnant Polish Konik mares during eleven months of pregnancy. Infrared thermography was conducted to image the lateral surface of mares’ abdomen (Px1) and flank area (Px2); P4, E1S, E2, and REL concentrations in serum were also determined. The evidence of the association between the area with the highest temperatures (Area of Tmax) and serum concentrations of P4 (the slope = 1.373; p = 0.9245) and REL (the slope = 1.342; p = 0.4324) were noted dependent across months of pregnancy. Measures of superficial body temperatures were found to change monthly, similarly to ambient temperatures, with no evidence of coincidence with changes in reproductive hormone concentrations. Individual thermal characteristics of the lateral surface of the abdomen differed between pregnant and non-pregnant mares in other periods. Differences in maximal and average temperature and Area of Tmax were observed from the sixth month of pregnancy, and those in minimal temperature were observed from the eighth month.

Reproductive Hormone Concentrations and Associated Anatomical Responses: Does Soy Formula Affect Minipuberty in Boys?

Soy formula feeding is common in infancy and is a source of high exposure to phytoestrogens, documented to influence vaginal cytology in female infants. Its influence on minipuberty in males has not been established. To assess the association between infant feeding practice and longitudinally measured reproductive hormones and hormone-responsive tissues in infant boys. The Infant Feeding and Early Development study was a prospective cohort of maternal-infant dyads requiring exclusive soy formula, cow milk formula, or breast milk feeding during study follow-up. In the 147 infant boy participants, serum testosterone, luteinizing hormone, stretched penile length, anogenital distance, and testis volume were longitudinally assessed from birth to 28 weeks. We examined feeding-group differences in age trajectories for these outcomes using mixed-effects regression splines. Median serum testosterone was at pubertal levels at 2 weeks (176 ng/dL [quartiles: 124, 232]) and remained in this range until 12 weeks in all feeding groups. We did not observe differences in trajectories of hormone concentrations or anatomical measures between boys fed soy formula (n = 55) and boys fed cow milk formula (n = 54). Compared with breastfed boys (n = 38), soy formula-fed boys had a more rapid increase in penile length (P = .004) and slower initial lengthening of anogenital distance (P = .03), but no differences in hormone trajectories. Reproductive hormone concentrations and anatomical responses followed similar trajectories in soy and cow milk formula-fed infant boys. Our findings suggest that these measures of early male reproductive development do not respond to phytoestrogen exposure during infancy.

Lower level of sexual maturation rating and reduced concentrations of reproductive hormones, luteinizing hormone, follicle stimulating hormone, testosterone and estradiol in short stature children with mutations in growth hormone secretagogue receptor 1a

Lower level of sexual maturation rating and reduced concentrations of reproductive hormones, luteinizing hormone, follicle stimulating hormone, testosterone and estradiol in short stature children with mutations in growth hormone secretagogue receptor 1a

Urinary metabolites of non-persistent pesticides and serum hormones in Spanish adolescent males

ObjectiveTo assess the relationship of urinary concentrations of ethylenethiourea (ETU), the main degradation product of ethylene bis-dithiocarbamate fungicides, 3-phenoxybenzoic acid (3-PBA), a common metabolite of many pyrethroids, and 1-naphthol (1N), a metabolite of the carbamate insecticide carbaryl, with hormone concentrations in adolescent males; and to examine interactions between pesticide metabolites and polymorphisms in xenobiotic metabolizing enzymes, including CYP2C19 and CYP2D6, in relation to hormone concentrations. MethodsA cross-sectional study was conducted in 134 males from the Spanish Environment and Childhood (INMA)-Granada cohort. Urine and serum samples were collected from participants during the same clinical visit at the age of 15–17 years. First morning urine void was analyzed for concentrations of ETU, 3-PBA, and 1N. Serum was analyzed for concentrations of reproductive hormones (testosterone, 17β-estradiol [E2], dehydroepiandrosterone sulfate [DHEAS], sex hormone binding globulin [SHBG], luteinizing hormone [LH], follicle stimulating hormone [FSH], anti-Müllerian hormone [AMH], and prolactin), thyroid hormones (free thyroxine [FT4], total triiodothyronine [TT3], and thyroid stimulating hormone [TSH]), insulin growth factor 1 (IGF-1), adrenocorticotropic hormone (ACTH), and cortisol. CYP2C19 G681A and CYP2D6 G1846A polymorphisms were determined in blood from 117 participants. Multiple linear regression, interaction terms, and stratified analyses were performed. ResultsUrinary ETU was detected in 74.6% of participants, 1N in 38.1%, and 3-PBA in 19.4%. Positive associations between detectable 3-PBA and TT3 and between detectable 1N and DHEAS were found, and marginally-significant associations of 1N with reduced E2 and FSH were observed. Poor CYP2C19 and CYP2D6 metabolizers (GA and AA genotype carriers) showed a greater increase in DHEAS for detected versus undetected 1N compared with GG genotype carriers. Poor CYP2D6 metabolizers (1846 GA and AA genotypes) evidenced increased cortisol for detected versus undetected ETU. ConclusionsThe associations observed between urinary pesticide metabolites and altered thyroid and reproductive hormones are novel and should be verified in studies with larger sample size. Further research on gene-environment interactions is warranted to establish individual susceptibility to pesticides and the risk of adverse health effects.

Using reproductive hormone concentrations from the muscle of white sharks Carcharodon carcharias to evaluate reproductive status in the Northwest Atlantic Ocean

Novel, non-lethal approaches are needed to improve our current understanding of the reproductive biology and ecology of the white shark Carcharodon carcharias. Previous studies have demonstrated that concentrations of reproductive hormones in muscle tissue can be used as reliable indicators of reproductive status for many vertebrate species, including elasmobranchs. Here, we applied this method to assess the concentrations of testosterone (T) and estradiol (E2) in muscle biopsies from free-swimming white sharks at a known aggregation site off the coast of Cape Cod, Massachusetts (USA), in the Northwest Atlantic Ocean, to determine whether this technique could be used to evaluate the reproductive status of this species. A total of 14 muscle samples from 13 white sharks (7 males [1 sampled twice], 6 females), ranging in size from 3.3 to 4.2 m total length, were analyzed for this study. T and E2 were present in sufficient amounts to be quantified in 7 of the 8 (87.5%) male and 1 of the 6 (16.7%) female samples, respectively. As expected, most samples collected from immature individuals were below minimum detection thresholds. Hormone concentrations in males presumed to be adults were also generally low, suggesting these individuals were not actively producing sperm at the time of sample collection. Overall, the results herein are similar to those found in other species and indicate that concentrations of hormones in the skeletal muscle of subadult and adult white sharks can provide information on the reproductive status of individuals. This technique could have wide-ranging applications for the study of white shark reproduction in the future.

Dietary encapsulated Bacillus subtilis and essential oil supplementation improves reproductive performance and hormone concentrations of broiler breeders during the late laying period

This study was conducted to evaluate the effects of increasing inclusion rates of Bacillus subtilis and essential oil (BSEO) on egg production, hatching traits, egg quality, plasma antioxidant capacity, immune response, and hormone concentrations of broiler breeders during the late laying period. A total of 576 broiler breeders at 54 wk of age were randomly allocated to 4 treatments with 6 replicates of 24 broiler breeders per replicate. The experiment lasted for 12 wk and dietary treatments included corn-soybean meal-based diet supplemented with 0, 300, 600, and 900 mg/kg of BSEO. The BSEO supplementation decreased linearly (P < 0.05) the feed conversion ratio, the concentrations of tumor necrosis factor-gamma, and interleukin-6. As the dietary BSEO supplementation increased, the egg weight, fertility, hatchability, hatchability of fertile eggs, eggshell-breaking strength, eggshell thickness, yolk index, the activity of glutathione peroxidase, the concentrations of estradiol, parathyroid hormone, follicle-stimulating hormone, progesterone, and luteinizing hormone increased linearly (P < 0.05). In conclusion, BSEO contributed to better fertility, hatchability, and hatchability of fertile eggs and improved antioxidant capacity and immune response, and increased hormone concentrations in broiler breeders during the late laying period.

Isomaltooligosaccharide and Bacillus regulate the duration of farrowing and weaning-estrous interval in sows during the perinatal period by changing the gut microbiota of sows.

This study investigated the effects of isomaltooligosaccharide (IMO) and Bacillus in perinatal diets on the duration of farrowing and post-weaning estrus, serum reproductive hormone concentrations, and gut microbiota and its metabolites of sows. Multiparous sows (n = 130) were fed diets without IMO (control, CON group), or diets containing only IMO (IMO group), IMO and Bacillus subtilis (IMOS group), IMO and Bacillus licheniformis (IMOL group), and IMO and B. subtilis and B. licheniformis (IMOSL group), respectively. The results indicate that the duration of farrowing and post-weaning estrus was shorter in sows in the IMOS, IMOL, and IMOSL groups, and the weaning-estrous interval was lower in sows in the IMOL greoup. In addition, the lowest fecal score was observed in the IMOL group during d 106 to 112 of gestation. Sows in most of the treatment groups had a higher concentration of serum prolactin and prostaglandin at farrowing, but a lower serum concentration of estradiol, oxytocin, and progesterone on d 18 of lactation than sows in the CON group. The treatment groups had a higher abundance of Candidatus Methanoplasma and Bacillus and a lower abundance of Escherichia-Shigella in their feces at farrowing. Furthermore, the treatment groups had higher concentrations of total short-chain fatty acids (SCFA) in feces at farrowing and a higher concentration of branched fatty acids in feces on d 18 of lactation. Furthermore, the abundance of Bacillus in feces was positively correlated with serum prostaglandin concentrations and fecal total SCFA of sows at farrowing, but was negatively correlated with the duration of farrowing. Overall, dietary IMO and Bacillus supplementation affected the concentration of serum reproductive hormones and the duration of farrowing and post-weaning estrus, and the gut microbiota is a key factor.

A hybrid machine learning approach in modeling the impact of chromium concentration in blood and gonads on the concentration of the reproductive hormones of Urva auropunctatus

The toxic impact of chromium on hormonal concentrations of the Urva auropuctatus in a tannery industrial area has been analyzed through exposure to a sub-lethal contaminated environment. Chromium concentration in the body tissues (blood, testes, and ovaries) of the exposed Urva auropunctatus was found significantly higher than the control. Moreover, the concentrations of reproductive hormones (follicle-stimulating hormone (FSH), luteinizing hormone (LH), progesterone, estradiol, and testosterone) were reduced in chromium exposed animals. A hybrid approach of artificial neural network and fuzzy methods (adaptive neuro-fuzzy inference system (ANFIS)) has been designed in the modeling of hormonal concentration of Urva auropunctatus of control and experimental groups using the concentration of chromium in the body tissues. The ANFIS results in satisfactory estimation accuracy (minimum root mean square error (RMSE) = 0.01) in the estimation of the concentration of reproductive hormones.

Organophosphate pesticide exposure, hormone levels, and interaction with PON1 polymorphisms in male adolescents

ObjectiveTo examine the association between urinary metabolites of organophosphate (OP) pesticides and serum concentrations of thyroid and reproductive hormones in male adolescents and to assess the potential effect of interactions between OP pesticides and paraoxonase 1 (PON1) polymorphisms on hormone levels. MethodsStudy subjects (N = 117) were male 16- to 17-year-olds from the Environment and Childhood (INMA)-Granada cohort in Spain. Concentrations of 3,5,6-trichloro-2-pyridinol (TCPy), a metabolite of chlorpyrifos/chlorpyrifos-methyl, 2-isopropyl-6-methyl-4-pyrimidinol (IMPy), a metabolite of diazinon, and diethylthiophosphate (DETP) and diethyldithiophosphate (DEDTP), non-specific metabolites of OP pesticides, were measured in a spot urine sample from each subject and adjusted for creatinine. Levels of reproductive hormones (total testosterone [TT], estradiol [E2], dehydroepiandrosterone sulfate [DHEAS], sex hormone binding globulin [SHBG], luteinizing hormone [LH], follicle stimulating hormone [FSH], anti-Müllerian hormone [AMH], insulin growth factor 1 [IGF-1], and prolactin), thyroid hormones (free thyroxine [FT4], total triiodothyronine [TT3], and thyroid stimulating hormone [TSH]), and PON1 Q192R and L55M polymorphisms were determined in blood drawn during the same clinical visit. ResultsMultiple linear regression models showed that detectable levels of TCPy were associated with an increase in DHEAS and decreases in E2, FSH, and AMH; detectable IMPy with increases in E2, DHEAS, FSH, AMH, and prolactin and decreases in SHBG and LH; and detectable DETP with marginally-significant increases in TT and TT3 and decreases in FSH, AMH, and prolactin. The effect of IMPy and DETP on DHEAS and TT levels, respectively, was higher in subjects that carried the PON1 55MM genotype, while the effect of TCPy, IMPy, and DETP on thyroid hormone levels was higher in PON1 192QR/RR or 55MM genotype carriers. ConclusionsIn male adolescents, non-occupational exposure to OP pesticides was associated with several changes in reproductive and thyroid hormone levels, and the magnitude of some associations was greater in adolescents genetically more susceptible to OP pesticide exposure who carry the PON1 55MM genotype.

Prenatal paraben exposure and anogenital distance and reproductive hormones during mini-puberty: A study from the Odense Child Cohort

BackgroundParabens are added to personal care products as antimicrobial preservatives. They have been suggested to have endocrine disrupting abilities. Prenatal exposure to parabens has been associated with reproductive endpoints including reduced male anogenital distance (AGD, distance from anus to genitals), which is sensitive to prenatal anti-androgenic exposure. ObjectivesTo study the associations between maternal paraben concentrations in second trimester urine and AGD and reproductive hormone concentrations at 3 months of age in offspring. MethodsPregnant women from Odense, Denmark were included in early pregnancy from 2010 to 12, and their children are being followed up. Fasting spot urine samples from 536 pregnant women were analyzed for methylparaben (MeP), ethyl-paraben (EtP), iso-propylparaben (i-PrP), n-propylparaben (n-PrP), n-butylparaben (n-BuP) and benzylparaben (BzP) by liquid chromatography tandem mass spectrometry and thereafter osmolarity adjusted. Three months after expected date of birth, AGD was measured in 452 children, and serum concentrations of follicle stimulating hormone (FSH), luteinizing (LH), testosterone, dehydroepiandrosterone-sulphate (DHEAS), androstenedione and 17-hydroxyprogesterone (17-OHP) were measured in 198 children. Maternal paraben exposure was categorized into tertiles or below and above level of detection, and sex-stratified multiple linear regression analyses were performed with AGD or reproductive hormones as outcomes. ResultsMost pregnant women had low concentrations of parabens in urine, but 10% exceeded the threshold for adverse estrogenic effects. Higher maternal paraben exposure was associated with shorter AGD in male offspring and longer AGD in girls, although only significant for MeP in boys. In addition, FSH, LH, DHEAS, 17-OHP concentrations were lower in girls with high prenatal paraben exposure, whereas no consistent pattern was found in boys. DiscussionThe endocrine disrupting abilities of parabens may affect humans at vulnerable time periods during development, which may have long term impact on reproductive function. This is the first study to find these associations in girls and our findings need confirmation.

Influence of ethanolic extract of avocado (Persea americana Mill.) seed flour on the estrous cycle, the serum concentrations of reproductive hormones, and the activities of oxidative stress markers in female cavies (Cavia porcellus L.).

Objective:The purpose of this study was to determine the effects of the ethanolic extract of avocado seed flour on the estrous cycle characteristics, the concentrations of reproductive hormones [luteinizing hormone (LH) and estradiol], and the activities of some tissues (ovarian and uterine) that are markers of oxidative stress in female guinea pigs (Cavia porcellus).Materials and Methods:Twenty-four female cavies with normal estrous cycles and equivalent body weights (464.25 and 71.88 gm) were randomly assigned to four groups, each with six females. The control group received 1 ml of distilled water orally, whereas the EE100, EE200, and EE400 groups received 100, 200, and 400 mg/kg bw of ethanolic extract of Persea americana seed, respectively. Following that, three consecutive estrous cycles were observed using vaginal smears. After the trial, the females were slaughtered, and blood and organs were gathered for study.Results:The mean duration of the estrus phase is considerably (p < 0.05) longer in group EE100 animals than in control animals. LH concentrations were substantially (p < 0.05) higher in females in group EE200 than in controls. Total cholesterol levels typically dropped in females in the extract groups, but only significantly (p < 0.05) in those in group EE100 compared to the control group. Serum estradiol levels increased considerably (p < 0.05) in treated females compared to controls. Catalase activity rose considerably (p < 0.05) in the ovaries of group EE400 when compared to the control. Superoxide dismutase activity rose considerably (p < 0.05) in the uterus of female cavies given the extract compared to the control.Conclusion:Avocado seed ethanolic extract prolongs the estrus phase, increases estradiol and LH levels, and protects the uterus from oxidative stress in female cavies.

Detection of steroid and thyroid hormones in mammalian teeth.

Endocrine tools can provide an avenue to better understand mammalian life histories and predict how individuals and populations may respond to environmental stressors; however, few options exist for studying long-term endocrine patterns in individual marine mammals. Here, we (i) determined whether hormones could be measured in teeth from four marine mammal species: narwhal (Monodon monoceros), beluga (Delphinapterus leucas), killer whale (Orcinus orca) and Atlantic walrus (Odobenus rosmarus rosmarus); (ii) validated commercially available enzyme immunoassay kits for use with tooth extracts; and (iii) conducted biological validations for each species to determine whether reproductive hormone concentrations in teeth correlated with age of sexual maturity. Tooth extracts from all species had measurable concentrations of progesterone, testosterone, 17β-estradiol, corticosterone, aldosterone and triiodothyronine (T3); however, cortisol was undetectable. Parallelism between the binding curves of assay kit standards and serially diluted pools of tooth extract for each species was observed for all measurable hormones. Slopes of accuracy tests ranged from 0.750 to 1.116, with r2 values ranging from 0.977 to 1.000, indicating acceptable accuracy. Biological validations were inconsistent with predictions for each species, with the exception of female killer whales (n = 2), which assumed higher progesterone and testosterone concentrations in mature individuals than immature individuals. Instead, we observed a decline in progesterone and testosterone concentrations from infancy through adulthood in narwhal (n = 1) and walruses (n = 2) and higher reproductive hormone concentrations in immature individuals than mature individuals in belugas (n = 8 and 10, respectively) and male killer whales (n = 1 and 2, respectively). While unexpected, this pattern has been observed in other taxa; however, further analytical and biological validations are necessary before this technique can be used to assess individual mammalian endocrine patterns.

Steroid hormones in Pacific walrus bones collected over three millennia indicate physiological responses to changes in estimated population size and the environment.

The Pacific walrus (Odobenus rosmarus divergens) is an iconic Arctic marine mammal and an important resource to many Alaska Natives. A decrease in sea ice habitat and unknown population numbers has led to concern of the long-term future health of the walrus population. There is currently no clear understanding of how walrus physiology might be affected by a changing Arctic ecosystem. In this study, steroid hormone concentrations (progesterone, testosterone, cortisol and estradiol) were analysed in walrus bones collected during archaeological [3585-200calendar years before present (BP)], historical [1880-2006 common era (CE)] and modern (2014-2016CE) time periods, representing ~ 3651years, to track changes in reproductive activity and cortisol concentrations (biomarker of stress) over time. Our results show that modern walrus samples have similar cortisol concentrations (median = 43.97 ± standard deviation 904.38ng/g lipid) to archaeological walruses (38.94 ± 296.17ng/g lipid, P = 0.75). Cortisol concentrations were weakly correlated with a 15-year average September Chukchi Sea ice cover (P = 0.002, 0.02, r 2 = 0.09, 0.04, for females and males, respectively), indicating a possible physiological resiliency to sea ice recession in the Arctic. All steroid hormones had significant negative correlations with mean walrus population estimates from 1960 to 2016 (P < 0.001). Progesterone in females and testosterone in males exhibited significant correlations with average September Chukchi Sea ice cover for years 1880-2016 (P < 0.001 for both, r2 = 0.34, 0.22, respectively). Modern walruses had significantly lower (P = < 0.001) reproductive hormone concentrations compared with historic walruses during times of rapid population increase, indicative of a population possibly at carrying capacity. This is the first study to apply bone as a tool to monitor long-term changes in hormones that may be associated with changes in walrus population size and sea ice cover.

Effects of anesthetic MS-222 on stress and reproduction of South American silver catfish (Rhamdia quelen) males

Anesthesia is a common practice used in fish research and aquaculture. It is important to understand anesthetic effects on the animal and tissues of interest to ensure validity of data and to improve animal welfare in research and fish production endeavors. The production of some captive fish species is only possible by imposing artificial reproduction procedures, and manipulation of fish for these purposes is a stressor. The purpose of this study, therefore, was to evaluate effects of different concentrations (100, 200, and 300 mg/L) of the anesthetic MS-222 (tricaine methanesulfonate) on cortisol concentrations and effects on sperm quality in Rhamdia quelen. After hormonal induction of gamete production, 28 sexually mature males were randomly assigned to treatments, and milt and blood samples were collected. Anesthesia induction time, motility rate, sperm concentration and morphology, plasma cortisol concentrations, and reproductive hormone concentrations (testosterone, 17-α-hydroxyprogesterone, and estradiol) were evaluated. Sperm motility was greater in the control than 300 mg/L treatment group but did not differ among the control, 100, and 200 mg/L groups. The estradiol concentration was greater in non- anesthetized than anesthetized Rhamdia quelen, but plasma cortisol concentrations did not differ among treatment groups (182.50 ± 42.03 ng/mL). The anesthetic MS-222 at concentrations of 100, 200, and 300 mg/L did not inhibit the stress response due to handling of Rhamdia quelen males. In addition, treatment with MS-222 was not effective in inhibiting detrimental effects on sperm quality because this treatment was associated with impaired sperm motility and lesser concentrations of plasma estradiol.