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1.
Reprod Fertil Dev ; 30(8): 1066-1076, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29309736

RESUMO

Sixteen cases of spontaneous pregnancy loss (11 of singletons and five of pairs of twins) are described. The losses occurred between gestation Days 13 and 25 in 12 mares being monitored almost daily by transrectal ultrasonography (for measurement of conceptus growth) and blood sampling (for determination of maternal plasma progesterone concentrations as evidence of luteolysis) in experimental studies of early pregnancy. In 10 of the 16 cases the uterus was flushed and eight conceptuses were recovered for morphological assessment. Five of the 11 losses of singletons occurred before Day 16 and, with one exception, were preceded or accompanied by luteolysis. The remaining six singleton pregnancies failed after Day 16, with two cases evidencing luteolysis beforehand. Thus, overall, 6/11 singleton losses were associated with luteolysis while 5/11 were not. The five cases of simultaneous loss or degeneration of twin conceptuses all occurred on Day 19 or 20, preceded by luteolysis in only one case. These observations suggest that while the causes of spontaneous early pregnancy failure are multifactorial, luteolysis might contribute to the problem more often than has been previously contended.


Assuntos
Aborto Espontâneo/etiologia , Aborto Animal/etiologia , Desenvolvimento Embrionário/fisiologia , Luteólise/sangue , Progesterona/sangue , Aborto Espontâneo/sangue , Aborto Animal/sangue , Animais , Feminino , Cavalos , Gravidez
2.
Biol Reprod ; 93(3): 77, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26224003

RESUMO

Steroid production and metabolism by early conceptuses are very important for the establishment and maintenance of pregnancy in horses. Our earlier work suggested the possible formation of 5alpha-reduced steroids in equine conceptuses. We have now demonstrated the formation of 5alpha-reduced metabolites of androstenedione, testosterone, and progesterone by the embryo and its membranes. A total of 44 conceptuses were collected from 26 mares between 20 and 31 days of pregnancy. Tissues from the embryo proper and from the separated components of the conceptus (bilaminar and trilaminar trophoblast, allantois) were incubated with tritium-labeled substrates. 5Alpha-reduced metabolites (5alpha-dihydro- and 3beta,5alpha-tetrahydro- steroids) as radiolabeled products were identified from a series of chromatographic steps using four solvent systems for high-performance liquid chromatography. Use of a 5alpha-reductase inhibitor confirmed the metabolites were indeed 5alpha-reduced steroids. For the embryo, the only products from androstenedione were 5alpha-dihydroandrostenedione and 3beta,5alpha-tetrahydroandrostenedione, with no evidence of more polar metabolites; there was some 3beta,5alpha-tetrahydrotestosterone but no 5alpha-dihydrotestosterone from testosterone, and formation of androstenedione was followed by the production of 5alpha-dihydroandrostenedione and 3beta,5alpha-tetrahydroandrostenedione. The major 5alpha-reduced product from progesterone was 3beta,5alpha-tetrahydroprogesterone, with lesser amounts of 5alpha-dihydroprogesterone. For the membranes, reductions to tetrahydro, 5alpha-reduced steroids were prominent in most instances, but also present were considerable amounts of products more polar than the substrates. The well-recognized activity of some 5alpha-reduced steroids--for example, 5alpha-dihydrotestosterone in male sexual differentiation--provokes interest in their even earlier appearance, as seen in this study, and suggests a possible role for them in early embryonic development in horses and, more generally, in other species.


Assuntos
Embrião de Mamíferos/metabolismo , Cavalos/metabolismo , Esteroides/metabolismo , 3-Oxo-5-alfa-Esteroide 4-Desidrogenase/metabolismo , Inibidores de 5-alfa Redutase/farmacologia , Androstenodiona/metabolismo , Animais , Aromatase/metabolismo , Membranas Extraembrionárias/metabolismo , Feminino , Hidroxiesteroides/metabolismo , Oxirredução , Gravidez , Progesterona/metabolismo , Sulfotransferases/metabolismo , Testosterona/metabolismo
3.
Fish Physiol Biochem ; 40(6): 1887-97, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25148794

RESUMO

The goal of the study was to determine whether the metabolic clearance of cortisol from rainbow trout (Oncorhynchus mykiss) ovarian follicles is affected by the level of ovarian steroidogenesis, and whether it involves the activation of glucocorticoid receptors (GRs). Ovarian follicles were incubated in vitro; the adenylate cyclase activator, forskolin, was used to stimulate ovarian steroidogenesis, and the modulation of GR activity was brought about using GR agonists (cortisol and dexamethasone) or the GR antagonist, mifepristone (RU486). The follicles were co-incubated with [2, 4, 6, 7 (3)H] cortisol, and the tritium-labelled steroid products were separated by HPLC. In addition, the rates of expression of genes encoding for the two forms of GR (gr1 and gr2) were measured. Cortisone, cortisol sulphate, and cortisone sulphate were the major glucocorticoid products of cortisol metabolism, indicative of the action of 11ß-hydroxysteroid dehydrogenase and glucocorticoid sulphotransferase in the follicular cells. There were no effects of RU486 or forskolin on the rates of [(3)H]cortisol metabolism suggesting that cortisol metabolism by ovarian follicles was independent of GR activation, and not influenced by increased activation of gonadal reproductive steroidogenesis.


Assuntos
Hidrocortisona/metabolismo , Oncorhynchus mykiss/fisiologia , Folículo Ovariano/metabolismo , Receptores de Glucocorticoides/metabolismo , Animais , Colforsina/farmacologia , Dexametasona/farmacologia , Feminino , Regulação da Expressão Gênica , Glucocorticoides/farmacologia , Antagonistas de Hormônios/farmacologia , Hidrocortisona/genética , Mifepristona/farmacologia , Receptores de Glucocorticoides/genética , Vasodilatadores/farmacologia
4.
Psychol Rep ; 112(1): 14-9, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23654023

RESUMO

Estimates of per capita centenarians in a Utah population varied between one per 12,864 and one per 4,675, depending on the data that were used, the population assumptions that were made, and the boundary limits that were employed. In general, caution is warranted in claims about the existence of longevity hotspots.


Assuntos
Censos , Longevidade/fisiologia , Distribuição por Idade , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Análise de Sobrevida , Utah/epidemiologia , Utah/etnologia
5.
Reproduction ; 144(6): 713-22, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23081894

RESUMO

Mid-vitellogenic stage rainbow trout (Oncorhynchus mykiss) ovarian follicles (both intact and yolk free (YF)), ovulated oocytes and embryos were co-incubated with [2,4,6,7-(3)H]cortisol for 18 h to determine the degree and nature of the metabolism and biotransformation of the glucocorticoid. There was evidence of the conversion of cortisol to the less biologically potent glucocorticoid, cortisone, and the formation of glucocorticoid sulphates (both cortisol and cortisone) for all cell and tissue samples, suggesting the presence of 11ß-hydroxysteroid dehydrogenase (11ß-HSD) and glucocorticoid sulphotransferase (GST) activity at all stages; however, GST activity was particularly marked in both intact and YF ovarian follicles, suggesting an important role of follicles in limiting the exposure of oocyte to maternal cortisol. As there was no evidence of 11ß-HSD or GST activity in ovarian fluid, the findings affirm that ovarian follicles (probably the thecal and granulosa cells) provide a barrier against the transfer of cortisol to the oocytes by forming sulphated steroids, whereas ovulated oocytes and early embryos have a more limited capacity to either metabolize or conjugate cortisol and are therefore more vulnerable at the post-ovulatory and early embryonic stages to increases in exposure to the glucocorticoid.


Assuntos
11-beta-Hidroxiesteroide Desidrogenases/metabolismo , Hidrocortisona/metabolismo , Oncorhynchus mykiss/metabolismo , Folículo Ovariano/enzimologia , Sulfotransferases/metabolismo , Animais , Cromatografia Líquida de Alta Pressão , Embrião não Mamífero/enzimologia , Feminino , Oócitos/enzimologia , Estresse Fisiológico , Trítio
6.
Reprod Fertil Dev ; 24(8): 1071-8, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22950882

RESUMO

The embryo proper in early equine pregnancy has recently been shown to have a remarkable capacity for metabolism of oestrogens. High concentrations of oestrogens in yolk-sac fluid could provide substrate for local metabolism in tissues of the embryo proper and this activity could have significance for early development. Due to the high level of oestrogen metabolism in the embryo proper we examined the possibility that it could also biosynthesise oestrogens. Conceptuses were collected in the fourth week of pregnancy (n=23) and the embryo was separated from extraembryonic tissues for incubation with [(3)H]androstenedione. Steroids were recovered from media by solid-phase extraction and eluted as unconjugated and conjugated fractions. Profiles of free and sulfoconjugated fractions, as well as the phenolic steroids extracted from them, were obtained by chromatography. Oestrone and oestradiol were seen clearly, indicating oestrogen biosynthesis, and the presence of more polar products, arising from metabolism of the primary oestrogens, gave further evidence that the embryo was capable of oestrogen biosynthesis. Aromatase activity was also demonstrated by detection of tritium loss, as (3)H(2)O, from incubations (n=3) with [1ß-(3)H]androstenedione. It is suggested that its oestrogen biosynthesis may have significance for the remarkable development of the vasculature in the embryo proper at this stage.


Assuntos
Embrião de Mamíferos/metabolismo , Estrogênios/biossíntese , Androstenodiona/metabolismo , Animais , Aromatase/metabolismo , Vasos Sanguíneos/embriologia , Embrião de Mamíferos/irrigação sanguínea , Desenvolvimento Embrionário , Feminino , Idade Gestacional , Gravidez , Trítio
7.
Reprod Fertil Dev ; 24(3): 411-24, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22401273

RESUMO

To advance the understanding of early pregnancy and pregnancy failure in horses, this study determined how luteolysis induced by cloprostenol (an analogue of prostaglandin F2α) affects conceptus development. Mares were injected on Days 12, 14, 16 or 18 of pregnancy with either cloprostenol (treatment groups, total n=83 pregnancies) or saline (controls, n=81), and growth of the conceptuses was monitored and compared by daily ultrasonography until they were collected transcervically on Days 15-22, 1-4 days after the injections. The comparisons were extended in the recovered conceptuses by counting somites, measuring the volume and osmolality of yolk-sac fluid and its concentrations of proteins, estrone sulfate and progesterone, and by assessing the morphology of the capsule and vascular system. When luteolysis was initiated on or before Day 16, most pregnancies survived until the time of collection and the conceptuses in respective treated and control groups on Days 15-20 were very similar except for some effects of treatment on the capsule and vascular development. In contrast, after luteolysis was initiated on Day 18, abortion often ensued within 3 days and most conceptuses collected had degenerated, therein constituting a predictable system in which to study the pathogenesis of a particular cause of pregnancy failure.


Assuntos
Blastocisto/efeitos dos fármacos , Dinoprosta/farmacologia , Cavalos/fisiologia , Luteólise/efeitos dos fármacos , Prenhez , Animais , Blastocisto/diagnóstico por imagem , Blastocisto/fisiologia , Cloprostenol/administração & dosagem , Cloprostenol/farmacologia , Dinoprosta/análogos & derivados , Dinoprosta/fisiologia , Desenvolvimento Embrionário/efeitos dos fármacos , Desenvolvimento Embrionário/fisiologia , Feminino , Fármacos para a Fertilidade Feminina/administração & dosagem , Fármacos para a Fertilidade Feminina/farmacologia , Idade Gestacional , Cavalos/metabolismo , Luteólise/fisiologia , Gravidez , Testes de Gravidez/métodos , Testes de Gravidez/veterinária , Fatores de Tempo , Ultrassonografia
8.
J Endocrinol ; 255(2): 53-59, 2022 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-35993430

RESUMO

Current heightened recognition of the importance of sulfated steroids led to the examination of conjugates in media from incubations of estrogens in tissues from the reproductive tract of stallions. Previously, we had reported a 'new' unidentified metabolite of estrone (E1) and [3H]-E1, located between 17ß-estradiol (E2) and E1 reference standards on chromatography (HPLC) and identified tentatively as a stable 5α,6α-estrone epoxide. Stallion tissues were minced and incubated for 2 h with [3H]-E1 (1 × 106 cpm). Solid-phase extraction of unconjugated and conjugated steroids from media was followed by liquid scintillation counting (LSC), where radioactivity was mostly in the conjugate fractions (>80%). HPLC of conjugated steroids used an isocratic solvent system of acetonitrile/water (8:92) at 700 µL/min with detection by LSC. A radioactive peak between reference standards of E1 and E2 sulfates was examined, after solvolysis, in a second solvent system. Sulfated steroids yielded largely E1, whereas acid treatment of the unconjugated E1 epoxide had earlier formed 6α-OH-E1 almost exclusively. With sulfatase enzyme, at neutral pH, radioactivity was also seen mostly as E1 with trace amounts of polar material. Reduction with KBH4, however, led also to desulfation; radioactivity had alignment with E2 but even more had low retention times as for 6α/6ß-OH-E2. These findings point to a different hydrolysis for desulfation; even more, they reveal an additional oxygen atom at C6 and are supportive of biological formation of 5α,6α-epoxides of E1 and E2. As possible alternatives to catechol estrogens, implicated in cancer, the 'new' estrogen metabolites and their sulfated forms may have special interest.


Assuntos
Compostos de Epóxi , Estrona , Animais , Estradiol/metabolismo , Estrogênios/metabolismo , Estrona/metabolismo , Cavalos , Masculino , Solventes , Sulfatos
9.
Reproduction ; 138(6): 953-60, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19710203

RESUMO

Estrogen production by the trophoblast is considered important in early equine pregnancy and leads to high concentrations in yolk-sac (Y-S) fluid. The embryo proper is a potential site for their action. We examined estrogen metabolism in the embryo proper because some actions of estrogens are derived from locally formed metabolites. The embryo proper, as well as separated extraembryonic tissues, of conceptuses collected about day 25 of pregnancy, were incubated with (3)[H]-estrone (E(1)) and (3)[H]-estradiol (E(2)). Steroids were recovered from media by solid-phase extraction and eluted separately as unconjugated and conjugated fractions. Profiles of free and sulfo-conjugated fractions were obtained by HPLC. Some differences and similarities were noted for the embryo proper as compared to the extraembryonic tissues. No reduction of E(1) to E(2) was noted for the embryo proper and allantois, but some was seen with the bilaminar Y-S wall. Less conversion of E(2) to E(1) occurred in the embryo proper than in the extraembryonic tissues. Profiles for hydrolyzed sulfates from incubation of the embryo proper were very similar for both substrates, mainly with E(1) present. Thus, low levels of reductase and high levels of oxido- activities were apparent for the 17beta-hydroxysteroid dehydrogenase enzymes. Further evidence of an active role for the embryo proper was seen as minor, polar products, and an unknown compound eluting between E(2) and E(1). These findings show, for the first time, that the embryo proper can metabolize estrogens that are found in Y-S fluid - a function of potential significance at this stage in its development.


Assuntos
Embrião de Mamíferos/metabolismo , Estrogênios/metabolismo , Cavalos/embriologia , Cavalos/metabolismo , Prenhez , Líquido Amniótico/química , Líquido Amniótico/metabolismo , Animais , Cromatografia Líquida de Alta Pressão , Embrião de Mamíferos/química , Estradiol/análise , Estradiol/metabolismo , Estradiol/farmacocinética , Estrogênios/análise , Estrona/análise , Estrona/metabolismo , Estrona/farmacocinética , Membranas Extraembrionárias/metabolismo , Feminino , Idade Gestacional , Cavalos/fisiologia , Gravidez , Esteroides/análise , Esteroides/metabolismo , Trítio/análise , Trítio/farmacocinética
10.
J Steroid Biochem Mol Biol ; 167: 39-47, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-27989795

RESUMO

Oxidative metabolism of estrogens is an important feature in liver and some non-hepatic tissues. In initial studies on estrogen metabolism in tissues from the reproductive tract of the stallion, where testicular estrogen secretion is remarkably high, a prominent radiolabeled product from [3H]-estrone (E1) was noted on chromatography; it had a retention time (Rt) between 17ß-estradiol (E2) and E1. Unexpectedly, when non-radiolabeled E1 was the substrate no UV absorption at 280nm was seen at the Rt for the [3H]-labeled product-suggesting a non-aromatic ring A. The following efforts were made to reveal more about the nature of the "unknown" compound. Reduction and acetylation showed, separately, the presence of a single keto and hydroxyl group. Exposure to acid gave a single radiolabeled peak with Rt of 6α-hydroxy-E1-suggesting the presence of a third molecule of oxygen. Mass spectrometry with limited material was inconclusive but supportive for a formula of C18H22O3. Thus, an epoxide involving the aromatic ring of E1 is suggested as a labile intermediate in the formation of the "unknown" metabolite. Estrogen epoxides as labile, reactive intermediates have been considered as potential precursors of the 2- and 4-hydroxy catechol estrogens with implications in breast cancer [Soloway, 2007]. Because of the association of the "unknown" metabolite with 6α-hydroxy-E1, the structural form proposed for the stable epoxide is that for 5α,6α-epoxy-estrone. This represents an alternative to the production of the 2- and 4-hydroxy-catechol estrogens. The broad range in normal tissues where the "unknown" compound was shown to be a persistent metabolite (e.g. mouse mammary glands, ovary, uterus, brain, muscle, equine conceptus, stallion and domestic boar reproductive tracts) suggests more general biological implications.


Assuntos
Compostos de Epóxi/química , Estrona/análogos & derivados , Estrona/química , Animais , Catecóis/química , Cromatografia , Cromatografia Líquida de Alta Pressão , Estradiol/química , Estrogênios/química , Feminino , Cavalos , Hidrólise , Masculino , Espectrometria de Massas , Camundongos , Oxigênio/química , Espectrofotometria Ultravioleta , Sus scrofa , Suínos , Raios Ultravioleta
11.
Physiother Can ; 64(4): 397-413, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23997396

RESUMO

PURPOSE: To summarize the existing literature examining constraint-induced movement therapy (CIMT), relative to dose-matched control interventions, for upper-limb (UL) dysfunction in adult survivors of stroke. METHODS: CINAHL, Cochrane Library, Embase, NARIC/CIRRIE-Rehabdata, PEDro, PubMed, Scopus, and Web of Science were searched from their inception to February 2011. Trial quality was described using the PEDro scale. The findings were summarized with meta-analysis. RESULTS: For the 22 trials identified, the mean (SD) PEDro score was 6.4 (1.2). Meta-analysis showed CIMT to be superior to dose-matched interventions based on indicators of UL motor capacity (15 trials, n=432; standardized mean difference [SMD]=0.47, 95% CI, 0.27-0.66) and UL ability (14 trials, n=352; SMD=0.80, 95% CI, 0.57-1.02); Functional Independence Measure scores (6 trials, n=182; mean difference [MD]=5.05, 95% CI, 2.23-7.87); and Motor Activity Log scores (Amount of Use: 12 trials, n=318; MD=1.05, 95% CI, 0.85-1.24; Quality of Movement: 11 trials, n=330; MD=0.89, 95% CI, 0.69-1.08). CONCLUSIONS: Compared to control interventions of equal duration and dose, CIMT produced greater improvements in a variety of indicators of UL function in adult survivors of a stroke with residual movement of their upper limb.


Objectif : Faire la synthèse de la littérature existante traitant de la thérapie par contrainte induite (TCI) par rapport aux interventions de contrôle avec dosage équivalent dans les cas de dysfonctions des membres supérieurs chez les adultes ayant survécu à un accident vasculaire cérébral. Méthode : Une recherche a été effectuée dans CINAHL, dans la bibliothèque de Cochrane, dans Embase, NARIC/CIRRIE­Rehabdata, PEDro, PubMed, Scopus, et Web of Science depuis leur mise en ligne jusqu'en février 2011. La qualité des recherches a été évaluée à l'aide de l'échelle PEDro. Les conclusions ont été résumées à l'aide d'une méta-analyse. Résultats : Au total, 22 essais ont été répertoriés; la moyenne de leur cote à l'échelle PEDro était de 6,4 (SD1 de 0,2). La méta-analyse a révélé que la TCI est supérieure aux interventions de contrôle avec dosage équivalent pour les indicateurs de capacité motrice des membres supérieurs (15 essais, n=432; MDS=0,47; 95%IC, 0,27­0,66); capacité des membres supérieurs (14 essais, n=352; MDS=0,80; 95%IC, 0,57­1,02); mesure de l'autonomie fonctionnelle [Functional Independence Measure] (6 essais, n=182; DM=5,05; 95%IC, 2,23­7,87); et score du journal de l'activité motrice [Motor Activity Log] (quantité d'utilisation : 12 essais, n=318; DM=1,05; 95%IC, 0,85­1,24; qualité du mouvement : 11 essais, n=330; DM=0,89; 95%IC 0,69­1,08). Conclusions : Si on la compare aux interventions de contrôle de durée et avec dosage équivalents, la TCI suscite de plus grandes améliorations dans une variété d'indicateurs de la fonction des membres supérieurs chez les adultes ayant survécu à un AVC avec mouvement résiduel de leurs membres supérieurs.

12.
Exp Biol Med (Maywood) ; 237(2): 186-93, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22302707

RESUMO

Breeding soundness evaluation (BSE) is the primary assessment for determining the reproductive potential of male animals. This method, however, cannot be used to evaluate semen frequently or to predict future semen quality. Computerized analysis of ultrasonographic images provides information on histophysiological changes in male reproductive organs. We hypothesized that: (i) semen parameters would correlate with ultrasonographic characteristics of the distal region (cauda) of the epididymis and (ii) testicular ultrasound images and/or circulating testosterone concentration would predict future semen quality in the ram. Six adult rams underwent BSE and scrotal ultrasonography approximately 60 d apart (average duration of the spermatogenic cycle) both during the breeding (December and February) and non-breeding (June and August) seasons. An inverse correlation was found between pixel intensity (numerical pixel values) of the epididymes and percentage of sperm in semen with normal morphology (r = -0.46, P < 0.05). Pixel heterogeneity (standard deviation of pixel values) correlated negatively with percentage of sperm with normal morphology (r = -0.42, P < 0.05) and directly with percentage of spermatozoa with abnormal tails (r = 0.43, P < 0.05). Pixel heterogeneity of testicular parenchyma obtained approximately 60 d prior to semen evaluation inversely correlated with percentage of sperm with normal morphology (r = -0.73, P < 0.01) and sperm progressive motility (r = -0.76, P < 0.01), and directly with percentage of sperm with abnormal tails (r = 0.72, P < 0.01) and loose heads (r = 0.79, P < 0.01). We concluded that scrotal ultrasonography combined with computer-assisted analyses of epididymal and testicular echotexture in the ram was a valuable method for determining certain current and future semen parameters, respectively.


Assuntos
Epididimo/diagnóstico por imagem , Processamento de Imagem Assistida por Computador/métodos , Testículo/diagnóstico por imagem , Ultrassonografia/métodos , Animais , Humanos , Masculino , Oncologia/métodos , Análise de Regressão , Sêmen/fisiologia , Análise do Sêmen , Ovinos , Contagem de Espermatozoides , Motilidade dos Espermatozoides , Testículo/patologia
14.
Biol Reprod ; 71(4): 1120-7, 2004 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-15163615

RESUMO

Because estradiol (E(2)) production by the early equine conceptus is considered crucial to the establishment of pregnancy, the amounts of E(2), estrone (E(1)), and their sulfates (E(2)S, E(1)S) were measured by RIA in yolk-sac fluid of 63 conceptuses collected by transcervical lavage over the period of 11-26 days after ovulation. Amounts increased significantly with age of conceptus, especially for E(1)S. Then, the metabolism of E(2), which may be highly relevant for its action, was examined in the conceptus and endometrium over the period when the conceptus ceases to migrate within the uterus. Eleven conceptuses collected mainly on Days 12, 15, and 18, with endometrial biopsy samples taken immediately thereafter, were used for steroid metabolic studies. Trophoblastic and endometrial tissues were incubated with [(3)H]-labeled E(2) or E(1), and with [(14)C]-E(1) in one experiment. Steroids were recovered from the media by solid-phase extraction (SPE) and eluted separately as unconjugated and conjugated fractions. Conjugation increased from Day 12 for the trophoblast (more so by bilaminar than trilaminar tissues on Day 18) and was much greater for endometrium, with almost all as sulfoconjugates. HPLC profiles of free and sulfate fractions were obtained from a gradient of acetonitrile/water. Interconversion (E(2) right harpoon over left harpoon E(1)) by trophoblast varied with development; it favored E(2) in older conceptuses, more in bilaminar than trilaminar tissues. Some more polar products were also noted, with loss of tritium seen as [(3)H](2)O at SPE, and confirmed by HPLC in a second system with authentic reference steroids. Almost all radioactivity in the endometrium was present as E(2) in both free and sulfate fractions. It was concluded that local metabolism of E(2) is quantitatively significant and may play an important role in the actions of the large amounts of estradiol produced by the early equine conceptus.


Assuntos
Embrião de Mamíferos/metabolismo , Endométrio/metabolismo , Estrogênios/metabolismo , Cavalos/embriologia , Trofoblastos/metabolismo , Saco Vitelino/metabolismo , Animais , Líquidos Corporais/metabolismo , Embrião de Mamíferos/citologia , Feminino , Gravidez
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