67 INHIBITION OF 5α-REDUCTASE DURING LATE GESTATION IN THE MARE

2016 ◽  
Vol 28 (2) ◽  
pp. 163
Author(s):  
M. Wynn ◽  
E. Legacki ◽  
A. Conley ◽  
S. Loux ◽  
A. Esteller-Vico ◽  
...  
Keyword(s):  
Mixed Model ◽  
Late Gestation ◽  
Wilcoxon Test ◽  
Serum Concentrations ◽  
Gestational Length ◽  
Time Treatment ◽  
Chromatography Tandem Mass Spectrometry ◽  
Liquid Chromatography Tandem Mass ◽  
High Concentrations ◽  
And Control

During the latter half of pregnancy in the mare, circulating concentrations of progesterone (P4) are low and a major bioactive progestogen, 5α-dihydroprogesterone (DHP), is present in high concentrations. DHP is formed through the activity of 5α-reductase, which converts P4 to DHP. Further metabolites of DHP have been attributed to fetal and myometrial quiescence. The purpose of this study was to examine the effects of a 5α-reductase inhibitor (dutasteride) on P4 metabolism and onset of parturition. Pregnant mares (n = 5) were treated with dutasteride (0.01 mg kg–1; IM), and control mares (n = 4) received vehicle alone from 300 to 320 days of gestation or until foaling. Serum concentrations of P4 and DHP were determined with liquid chromatography/tandem mass spectrometry (LC/MS-MS) daily for 9 days preceding parturition. Endocrine data were analysed with a random effects mixed model with time, treatment (TRT), and time × TRT interaction. Gestational data were analysed with a Wilcoxon test. Although there was a significant effect of time on P4 and DHP, there was no effect of TRT or time × TRT on these progestogens. For the ratio of DHP/P4, there were significant effects of time, TRT, and time × TRT interaction such that the ratio of DHP/P4 was greater in the control than dutasteride-treated mares. Birth weight and gestational length were not different (P > 0.2) between the dutasteride-treated and control mares, although placental weights were greater (P < 0.05) in dutasteride-treated mares. Because the ratio of DHP/P4 was suppressed in dutasteride-treated mares, it appears that dutasteride was active in late gestational mares. Although gestational length and neonatal weights were not different between groups, placentas from dutasteride-treated mares were heavier than those from control mares. The reason for the increase in placental weights was not determined.

scholarly journals Inhibition of 5α-reductase alters pregnane metabolism in the late pregnant mare

Reproduction ◽  
2018 ◽  
Vol 155 (3) ◽  
pp. 251-258 ◽  
Author(s):  
Michelle A A Wynn ◽  
Barry A Ball ◽  
Erin Legacki ◽  
Alan Conley ◽  
Shavahn Loux ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Reductase Inhibitor ◽  
Tandem Mass ◽  
Gestational Length ◽  
Significant Treatment ◽  
Chromatography Tandem Mass Spectrometry ◽  
Progesterone Metabolism ◽  
Liquid Chromatography Tandem Mass ◽  
And Control

In the latter half of gestation in the mare, progesterone concentrations decline to near undetectable levels while other 5α-reduced pregnanes are elevated. Of these, 5α-dihydroprogesterone and allopregnanolone have been reported to have important roles in either pregnancy maintenance or fetal quiescence. During this time, the placenta is necessary for pregnane metabolism, with the enzyme 5α-reductase being required for the conversion of progesterone to 5α-dihydroprogesterone. The objectives of this study were to assess the effects of a 5α-reductase inhibitor, dutasteride on pregnane metabolism (pregnenolone, progesterone, 5α-dihydroprogesterone, 20α-hydroxy-5α-pregnan-3-one, 5α-pregnane-3β,20α-diol and allopregnanolone), to determine circulating dutasteride concentrations and to assess effects of dutasteride treatment on gestational parameters. Pregnant mares (n = 5) received dutasteride (0.01 mg/kg/day, IM) and control mares (n = 4) received vehicle alone from 300 to 320 days of gestation or until parturition. Concentrations of dutasteride, pregnenolone, progesterone, 5α-dihydroprogesterone, 20α-hydroxy-5α-pregnan-3-one, 5α-pregnane-3β,20α-diol, and allopregnanolone were evaluated via liquid chromatography–tandem mass spectrometry. Samples were analyzed as both days post treatment and as days prepartum. No significant treatment effects were detected in pregnenolone, 5α-dihydroprogesterone, 20α-hydroxy-5α-pregnan-3-one, 5α-pregnane-3β,20α-diol or allopregnanolone for either analysis; however, progesterone concentrations were increased (P < 0.05) sixfold in dutasteride-treated mares compared to control mares. Dutasteride concentrations increased in the treated mares, with a significant correlation (P < 0.05) between dutasteride concentrations and pregnenolone or progesterone concentrations. Gestational length and neonatal outcomes were not significantly altered in dutasteride-treated mares. Although 5α-reduced metabolites were unchanged, these data suggest an accumulation of precursor progesterone with inhibition of 5α-reductase, indicating the ability of dutasteride to alter progesterone metabolism.

scholarly journals Detection of Antimicrobial Residues in Poultry Litter: Monitoring a Risk through a Selective and Sensitive HPLC–MS/MS Method

Animals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1399
Author(s):  
Karina Yévenes ◽  
Ekaterina Pokrant ◽  
Lina Trincado ◽  
Lisette Lapierre ◽  
Nicolás Galarce ◽  
...  
Keyword(s):  
High Performance ◽  
Limit Of Detection ◽  
Poultry Litter ◽  
Chromatography Tandem Mass Spectrometry ◽  
Antimicrobial Residues ◽  
Field Samples ◽  
Liquid Chromatography Tandem Mass ◽  
Commercial Poultry ◽  
Agriculture Fertilizer ◽  
And Control

Tetracyclines, sulphonamides, and quinolones are families of antimicrobials (AMs) widely used in the poultry industry and can excrete up to 90% of AMs administrated, which accumulate in poultry litter. Worryingly, poultry litter is widely used as an agriculture fertilizer, contributing to the spread AMs residues in the environment. The aim of this research was to develop a method that could simultaneously identify and quantify three AMs families in poultry litter by high-performance liquid chromatography–tandem mass spectrometry (HPLC–MS/MS). Samples of AMs free poultry litter were used to validate the method according to 657/2002/EC and VICH GL49. Results indicate that limit of detection (LOD) ranged from 8.95 to 20.86 μg kg−1, while limits of quantitation (LOQ) values were between 26.85 and 62.58 µg kg−1 of tetracycline, 4-epi-tetracycline, oxytetracycline, 4-epi-oxytetracycline, enrofloxacin, ciprofloxacin, flumequine, sulfachloropyridazine, and sulfadiazine. Recoveries obtained ranged from 93 to 108%. The analysis of field samples obtained from seven commercial poultry flocks confirmed the adequacy of the method since it detected means concentrations ranging from 20 to 10,364 μg kg−1. This provides us an accurate and reliable tool to monitor AMs residues in poultry litter and control its use as agricultural fertilizer.

scholarly journals Multiple cyanotoxin congeners produced by sub-dominant cyanobacterial taxa in riverine cyanobacterial and algal mats

2019 ◽  
Author(s):  
Laura T. Kelly ◽  
Keith Bouma-Gregson ◽  
Jonathan Puddick ◽  
Rich Fadness ◽  
Ken G. Ryan ◽  
...  
Keyword(s):  
Green Alga ◽  
Digital Pcr ◽  
Droplet Digital Pcr ◽  
Wilcoxon Test ◽  
Cladophora Glomerata ◽  
Chain Reaction ◽  
Chromatography Tandem Mass Spectrometry ◽  
Liquid Chromatography Tandem Mass ◽  
Polymerase Chain ◽  
Russian River

AbstractBenthic cyanobacterial proliferations in rivers are have been reported with increasing frequency worldwide. In the Eel and Russian rivers of California, more than a dozen dog deaths have been attributed to cyanotoxin toxicosis since 2000. Periphyton proliferations in these rivers comprise multiple cyanobacterial taxa capable of cyanotoxin production, hence there is uncertainty regarding which taxa are producing toxins. In this study, periphyton samples dominated by the cyanobacterial genera Anabaena spp. and Microcoleus spp. and the green alga Cladophora glomerata were collected from four sites in the Eel River catchment and one site in the Russian River. Samples were analysed for potential cyanotoxin producers using polymerase chain reaction (PCR) in concert with Sanger sequencing. Cyanotoxin concentrations were measured using liquid chromatography tandem-mass spectrometry, and anatoxin quota determined using droplet digital PCR. Sequencing indicated Microcoleus sp. and Nodularia sp. were the putative producers of anatoxins and nodularins, respectively, regardless of the dominant taxa in the mat. Anatoxin concentrations in the mat samples varied from 0.1 to 18.6 μg g−1 and were significantly different among sites (p < 0.01, Wilcoxon test); however, anatoxin quotas were less variable (< 5-fold). Dihydroanatoxin-a was generally the most abundant variant in samples comprising 38% to 71% of the total anatoxins measured. Mats dominated by the green alga C. glomerata contained both anatoxins and nodularin-R at concentrations similar to those of cyanobacteria-dominated mats. This highlights that even when cyanobacteria are not the dominant taxa in periphyton, these mats may still pose a serious health risk and indicates that more widespread monitoring of all mats in a river are necessary.

scholarly journals Estrone Is a Strong Predictor of Circulating Estradiol in Women Age 70 Years and Older

2020 ◽  
Vol 105 (9) ◽  
pp. e3348-e3354
Author(s):  
Susan R Davis ◽  
Alejandra Martinez-Garcia ◽  
Penelope J Robinson ◽  
David J Handelsman ◽  
Reena Desai ◽  
...  
Keyword(s):  
Health Outcomes ◽  
Postmenopausal Women ◽  
Limit Of Detection ◽  
Strong Predictor ◽  
Serum Concentrations ◽  
Community Based ◽  
Cross Sectional ◽  
A Value ◽  
Chromatography Tandem Mass Spectrometry ◽  
Liquid Chromatography Tandem Mass

Abstract Importance After menopause, estradiol (E2) is predominately an intracrine hormone circulating in very low serum concentrations. Objective The objective of this work is to examine determinants of E2 concentrations in women beyond age 70 years. Design and Setting A cross-sectional, community-based study was conducted. Participants A total of 5325 women participated, with a mean age of 75.1 years (± 4.2 years) and not using any sex steroid, antiandrogen/estrogen, glucocorticoid, or antiglycemic therapy. Main Outcome Measures Sex steroids were measured by liquid chromatography–tandem mass spectrometry. Values below the limit of detection (LOD; E2 11 pmol/L [3 pg/mL] were assigned a value of LOD/√2 to estimate total E2. Results E2 and estrone (E1) were below the LOD in 66.1% and 0.9% of women, respectively. The median (interdecile ranges) for E1 and detectable E2 were 181.2 pmol/L (range, 88.7-347.6 pmol/L) and 22.0 pmol/L (range, 11.0-58.7 pmol/L). Women with undetectable E2 vs detectable E2 were older (median age 74.1 years vs 73.8, P = .02), leaner (median body mass index [BMI] 26.8 kg/m2 vs 28.5, P &lt; .001), and had lower E1, testosterone and DHEA concentrations (P &lt; .001). A linear regression model, including age, BMI, E1, and testosterone, explained 20.9% of the variation in total E2, but explained only an additional 1.2% of variation over E1 alone. E1 and testosterone made significant contributions (r2 = 0.162, P &lt; .001) in a model for the subset of women with detectable E2. Conclusions Our findings support E1 as a principal circulating estrogen and demonstrate a robust association between E1 and E2 concentrations in postmenopausal women. Taken together with prior evidence for associations between E1 and health outcomes, E1 should be included in studies examining associations between estrogen levels and health outcomes in postmenopausal women.

Determination of three unsaturated fatty acids in pressure ulcer rats using an UPLC-MS/MS method

2020 ◽  
Vol 16 ◽  
Author(s):  
Fuman Cai ◽  
Yuwei Dong ◽  
Shaosheng Lou ◽  
Zeping Ma ◽  
Ting Wu ◽  
...  
Keyword(s):  
Ammonium Acetate ◽  
Unsaturated Fatty Acids ◽  
Serum Levels ◽  
Ultra Performance Liquid Chromatography ◽  
Release Time ◽  
Control Group ◽  
Serum Concentrations ◽  
Chromatography Tandem Mass Spectrometry ◽  
Liquid Chromatography Tandem Mass

Background: The serum levels of docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA) and arachidonic acid (AA) under the state of pressure ulcers (PUs) are still unclear. Introduction: In order to investigate serum levels of DHA, EPA, and AA in PUs rats, an ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/ MS) method was developed and validated. Methods: Chromatographic separation of DHA, EPA, AA was carried out on a BEH C18 column and gradient elute consisted of 5 mM ammonium acetate-0.1% formic acid and acetonitrile. Subsequently, fifty rats were divided into five groups (n=10), four PU groups (A-D) underwent various pressure and release time protocols, with group E as the control. The concentrations of DHA, EPA, AA from five groups were determination using validated method. Results: The results showed there was good linearity for DHA (327.3/283.4), EPA (301.2/257.0), and AA (303.1/258.9) within 0.05-6.4 μg/mL. In control group, the levels of DHA, AA and EPA were 1.16±0.68, 0.59±0.19 and 0.78±0.21 μg/mL. At the end of modeling, concentrations of DHA, EPA and AA were increased after long and persistent pressure (>8 h). Especially, the level of DHA was significantly higher (P<0.01) than that of control group. Conclusion: A stable, reliable and accurate UPLC-MS/MS for determination of DHA, EPA, AA in blood was developed. Serum concentrations of DHA, EPA and AA were altered differently after long and persistent pressure (>8 h), and DHA is a remarkable one.

scholarly journals First Detection of Tetrodotoxins in the Cotylean Flatworm Prosthiostomum trilineatum

Marine Drugs ◽  
2021 ◽  
Vol 19 (1) ◽  
pp. 40
Author(s):  
Rei Suo ◽  
Maho Kashitani ◽  
Hikaru Oyama ◽  
Masaatsu Adachi ◽  
Ryota Nakahigashi ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Tandem Mass Spectrometry ◽  
High Performance ◽  
Tandem Mass ◽  
Chromatography Tandem Mass Spectrometry ◽  
Liquid Chromatography Tandem Mass ◽  
High Concentrations ◽  
First Time

Several polyclad flatworm species are known to contain high levels of tetrodotoxin (TTX), but currently TTX-bearing flatworms seem to be restricted to specific Planocera lineages belonging to the suborder Acotylea. During our ongoing study of flatworm toxins, high concentrations of TTXs were detected for the first time in the flatworm Prosthiostomum trilineatum, suborder Cotylea, from the coastal area of Hayama, Kanagawa, Japan. Toxin levels were investigated by high performance liquid chromatography-tandem mass spectrometry (LC-MS/MS), revealing that this species contains comparable concentrations of toxins as seen in planocerid flatworms such as Planocera multitentaculata. This finding indicated that there may be other species with significant levels of TTXs. The distribution of TTXs among other flatworm species is thus of great interest.

scholarly journals Phosphoproteomic insights into processes influenced by the kinase-like protein DIA1/C3orf58

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4599 ◽  
Author(s):  
Agnieszka Hareza ◽  
Magda Bakun ◽  
Bianka Świderska ◽  
Małgorzata Dudkiewicz ◽  
Alicja Koscielny ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Endoplasmic Reticulum ◽  
Secretory Pathway ◽  
Signalling Pathways ◽  
Tandem Mass ◽  
Phosphopeptide Enrichment ◽  
Chromatography Tandem Mass Spectrometry ◽  
Proteomic Approach ◽  
Liquid Chromatography Tandem Mass ◽  
And Control

Many kinases are still ‘orphans,’ which means knowledge about their substrates, and often also about the processes they regulate, is lacking. Here, DIA1/C3orf58, a member of a novel predicted kinase-like family, is shown to be present in the endoplasmic reticulum and to influence trafficking via the secretory pathway. Subsequently, DIA1 is subjected to phosphoproteomics analysis to cast light on its signalling pathways. A liquid chromatography–tandem mass spectrometry proteomic approach with phosphopeptide enrichment is applied to membrane fractions of DIA1-overexpressing and control HEK293T cells, and phosphosites dependent on the presence of DIA1 are elucidated. Most of these phosphosites belonged to CK2- and proline-directed kinase types. In parallel, the proteomics of proteins immunoprecipitated with DIA1 reported its probable interactors. This pilot study provides the basis for deeper studies of DIA1 signalling.

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