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1.
Biology (Basel) ; 8(4)2019 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-31717753

RESUMO

The regulation of reproductive function by glucocorticoids occurs at all levels of the hypothalamo-pituitary-gonadal axis. Within the pituitary, glucocorticoids have been shown to directly alter gene expression in gonadotrophs, indicating that these cell types are sensitive to regulation by the glucocorticoid receptor. Whilst the major glucocorticoid metabolising enzymes, 11ß-hydroxysteroid dehydrogenase (11ßHSD; HSD11B1 and HSD11B2), have been described in human pituitary adenomas, the activity of these enzymes within different pituitary cell types has not been reported. Radiometric conversion assays were performed in αT3-1, LßT2 (gonadotrophs), AtT-20 (corticotrophs) and GH3 (somatolactotrophs) anterior pituitary cell lines, using tritiated cortisol, corticosterone, cortisone or 11-dehydrocorticosterone as substrates. The net oxidation of cortisol/corticosterone and net reduction of cortisone/11-dehydrocorticosterone were significantly higher in the two gonadotroph cells lines compared with the AtT-20 and GH3 cells after 4 h. Whilst these enzyme activities remained the same in αT3-1 and LßT2 cells over a 24 h period, there was a significant increase in glucocorticoid metabolism in both AtT-20 and GH3 cells over this same period, suggesting cell-type specific activity of the 11ßHSD enzyme(s). Stimulation of both gonadotroph cell lines with either 100 nM GnRH or PACAP (known physiological regulators of gonadotrophs) resulted in significantly increased 11ß-dehydrogenase (11ßDH) and 11-ketosteroid reductase (11KSR) activities, over both 4 and 24 h. These data reveal that gonadotroph 11ßHSD enzyme activity can act to regulate local glucocorticoid availability to mediate the influence of the HPA axis on gonadotroph function.

2.
J Clin Endocrinol Metab ; 98(8): 3375-83, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23678035

RESUMO

CONTEXT: Altered hepatic cortisol-cortisone metabolism by type 1 11ß-hydroxysteroid dehydrogenase (11ßHSD1) has previously been linked with polycystic ovary (PCO) syndrome (PCOS). OBJECTIVES: Our objectives were to establish whether ovarian 11ßHSD activities are also altered in PCOS and to determine whether any changes in ovarian cortisol metabolism might reflect exposure to elevated concentrations of insulin or androgens. DESIGN: Cortisol and cortisone concentrations were measured in follicular fluid aspirated from size-matched follicles dissected from normal, ovulatory, and anovulatory PCOs. Human granulosa-lutein cells, recovered during oocyte retrieval for assisted conception, were maintained in primary culture for 4 days, after which 11ßHSD1 activities were measured as the net oxidation of [(3)H]cortisol (100 nmol/L) in the absence and presence of insulin (100 nmol/L) with or without metformin (1 µmol/L) or a range of androgens/oxy-androgen metabolites (0.01-10 µmol/L). RESULTS: Intrafollicular cortisol to cortisone ratios were elevated in anovulatory PCOs (2.1 ± 0.4, P < .05, n = 13) but did not differ between follicles from ovulatory PCOs (1.6 ± 0.1, n = 24) and normal ovaries (1.2 ± 0.1, n = 14). 11ßHSD1 activities were lower in granulosa-lutein cells recovered from patients with PCOS compared with all other causes of infertility (median = 5.8 vs 14.9 pmol cortisone/4 h, respectively; P < .05). Cortisol oxidation was unaffected by insulin with or without metformin, dehydroepiandrosterone, and androstenedione, but was inhibited in a concentration-dependent manner by testosterone, 11ß-hydroxyandrostenedione, and 7α- and 7ß-hydroxy-dehydroepiandrosterone (P < .01). CONCLUSIONS: There is decreased inactivation of cortisol in follicles from anovulatory PCOS. This may reflect inhibition of 11ßHSD1 by androgens and their 7/11-oxy-metabolites, local concentrations of which are increased in PCOS, and may contribute to the block to folliculogenesis seen in PCOS.


Assuntos
11-beta-Hidroxiesteroide Desidrogenases/antagonistas & inibidores , Androgênios/farmacologia , Anovulação/metabolismo , Ovário/enzimologia , Síndrome do Ovário Policístico/metabolismo , 11-beta-Hidroxiesteroide Desidrogenases/metabolismo , Adulto , Cortisona/metabolismo , Relação Dose-Resposta a Droga , Feminino , Humanos , Hidrocortisona/metabolismo , Infertilidade Feminina/etiologia , Insulina/farmacologia , Metformina/farmacologia , Pessoa de Meia-Idade
3.
Cell Tissue Res ; 352(3): 751-60, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23568656

RESUMO

In target tissues, cortisol is metabolised by two 11ß-hydroxysteroid dehydrogenase (11ßHSD) isoenzymes, namely 11ßHSD1 and 11ßHSD2, both of which are co-expressed in the boar testis and reproductive tract. The present study has assessed whether cortisol-cortisone metabolism in boar testis and caput epididymidis can be regulated via the gonadotrophin-cAMP signalling pathway. 11ßHSD activities were measured by using a radiometric conversion assay in static tissue culture. In both testis and caput epididymidis, the net reduction of cortisone but not the net oxidation of cortisol, was significantly decreased by luteinising hormone (by 53 ± 20% and 45 ± 9%, respectively, P < 0.05), forskolin (by 60 ± 7% and 57 ± 9%, respectively, P < 0.01) and 8-bromo-cAMP (by 54 ± 4% and 64 ± 1%, respectively, P < 0.01). This suppression of 11-ketosteroid reductase activity in the boar testis by forskolin could be attenuated by the protein kinase A (PKA) inhibitor, H89. Hence, within the boar testis and the caput epididymidis, the local actions of glucocorticoids are modulated by gonadotrophin-cAMP-PKA signalling via their selective effects on the reductase activity of 11ßHSD.


Assuntos
AMP Cíclico/metabolismo , Epididimo/metabolismo , Glucocorticoides/metabolismo , Gonadotropinas/metabolismo , Transdução de Sinais , Suínos/metabolismo , Testículo/metabolismo , 11-beta-Hidroxiesteroide Desidrogenases/metabolismo , 8-Bromo Monofosfato de Adenosina Cíclica/farmacologia , Animais , Células Cultivadas , Colforsina/farmacologia , Cortisona/metabolismo , Dissecação , Epididimo/citologia , Epididimo/efeitos dos fármacos , Hormônio Foliculoestimulante/farmacologia , Humanos , Hidrocortisona/metabolismo , Hormônio Luteinizante/farmacologia , Masculino , Transporte Proteico/efeitos dos fármacos , Radiometria , Receptores de Glucocorticoides/metabolismo , Reprodutibilidade dos Testes , Transdução de Sinais/efeitos dos fármacos , Testículo/citologia , Testículo/efeitos dos fármacos
4.
PLoS One ; 7(11): e49553, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23152920

RESUMO

Valproic acid (VPA) is used widely to treat epilepsy and bipolar disorder. Women undergoing VPA treatment reportedly have an increased incidence of polycystic ovarian syndrome (PCOS)-like symptoms including hyperandrogenism and oligo- or amenorrhoea. To investigate potential direct effects of VPA on ovarian steroidogenesis we used primary bovine theca (TC) and granulosa (GC) cells maintained under conditions that preserve their 'follicular' phenotype. Effects of VPA (7.8-500 µg/ml) on TC were tested with/without LH. Effects of VPA on GC were tested with/without FSH or IGF analogue. VPA reduced (P<0.0001) both basal (70% suppression; IC(50) 67±10 µg/ml) and LH-induced (93% suppression; IC(50) 58±10 µg/ml) androstenedione secretion by TC. VPA reduced CYP17A1 mRNA abundance (>99% decrease; P<0.0001) with lesser effects on LHR, STAR, CYP11A1 and HSD3B1 mRNA (<90% decrease; P<0.05). VPA only reduced TC progesterone secretion induced by the highest (luteinizing) LH dose tested; TC number was unaffected by VPA. At higher concentrations (125-500 µg/ml) VPA inhibited basal, FSH- and IGF-stimulated estradiol secretion (P<0.0001) by GC without affecting progesterone secretion or cell number. VPA reversed FSH-induced upregulation of CYP19A1 and HSD17B1 mRNA abundance (P<0.001). The potent histone deacetylase (HDAC) inhibitors trichostatin A and scriptaid also suppressed TC androstenedione secretion and granulosal cell oestrogen secretion suggesting that the action of VPA reflects its HDAC inhibitory properties. In conclusion, these findings refute the hypothesis that VPA has a direct stimulatory action on TC androgen output. On the contrary, VPA inhibits both LH-dependent androgen production and FSH/IGF-dependent estradiol production in this in vitro bovine model, likely by inhibition of HDAC.


Assuntos
Anticonvulsivantes/farmacologia , Células da Granulosa/metabolismo , Esteroides/biossíntese , Células Tecais/metabolismo , Ácido Valproico/farmacologia , Androstenodiona/metabolismo , Animais , Bovinos , Contagem de Células , Sobrevivência Celular/efeitos dos fármacos , Estradiol/metabolismo , Feminino , Hormônio Foliculoestimulante/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Células da Granulosa/citologia , Células da Granulosa/efeitos dos fármacos , Inibidores de Histona Desacetilases/farmacologia , Fator de Crescimento Insulin-Like I/farmacologia , Hormônio Luteinizante/farmacologia , Progesterona/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Células Tecais/citologia , Células Tecais/efeitos dos fármacos
5.
Biochem Biophys Res Commun ; 404(1): 62-7, 2011 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-21094146

RESUMO

Cortisol-based therapy is one of the most potent anti-inflammatory treatments available for skin conditions including psoriasis and atopic dermatitis. Previous studies have investigated the steroidogenic capabilities of keratinocytes, though none have demonstrated that these skin cells, which form up to 90% of the epidermis are able to synthesise cortisol. Here we demonstrate that primary human keratinocytes (PHK) express all the elements required for cortisol steroidogenesis and metabolise pregnenolone through each intermediate steroid to cortisol. We show that normal epidermis and cultured PHK express each of the enzymes (CYP11A1, CYP17A1, 3ßHSD1, CYP21 and CYP11B1) that are required for cortisol synthesis. These enzymes were shown to be metabolically active for cortisol synthesis since radiometric conversion assays traced the metabolism of [7-(3)H]-pregnenolone through each steroid intermediate to [7-(3)H]-cortisol in cultured PHK. Trilostane (a 3ßHSD1 inhibitor) and ketoconazole (a CYP17A1 inhibitor) blocked the metabolism of both pregnenolone and progesterone. Finally, we show that normal skin expresses two cholesterol transporters, steroidogenic acute regulatory protein (StAR), regarded as the rate-determining protein for steroid synthesis, and metastatic lymph node 64 (MLN64) whose function has been linked to cholesterol transport in steroidogenesis. The expression of StAR and MLN64 was aberrant in two skin disorders, psoriasis and atopic dermatitis, that are commonly treated with cortisol, suggesting dysregulation of epidermal steroid synthesis in these patients. Collectively these data show that PHK are capable of extra-adrenal cortisol synthesis, which could be a fundamental pathway in skin biology with implications in psoriasis and atopic dermatitis.


Assuntos
3-Hidroxiesteroide Desidrogenases/metabolismo , Dermatite Atópica/enzimologia , Epiderme/enzimologia , Hidrocortisona/biossíntese , Queratinócitos/enzimologia , Psoríase/enzimologia , Esteroide Hidroxilases/metabolismo , Células Cultivadas , Humanos , Pregnenolona/metabolismo
6.
J Steroid Biochem Mol Biol ; 115(3-5): 98-106, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19500728

RESUMO

In light of studies implicating glucocorticoids in the control of testicular steroidogenesis and/or spermatogenesis, the objective of this study was to characterise the expression and activities of the 11beta-hydroxysteroid dehydrogenase (11betaHSD) enzymes in the testis and reproductive tract of the pre-pubertal pig. Although 11betaHSD1 and 11betaHSD2 mRNA transcripts and proteins were co-expressed in all regions of the reproductive tract, cortisol-cortisone inter-conversion was detectable in the testis, caput epididymidis and bulbourethral glands only. In homogenates of these 3 tissues, the apparent K(m) for NADP(+)- and NAD(+)-dependent 11beta-dehydrogenase activities ranged between 152-883 and 47-479 nmoll(-1), respectively. Irrespective of the pyridine nucleotide co-substrate, estimates of V(max) were consistently two orders of magnitude higher in the testis. Moreover, while, in each tissue, levels of cortisol oxidation were comparable in the presence of either NADP(+) or NAD(+), maximal rates of NAD(P)(+)-dependent cortisol oxidation were up to 33-fold greater than the V(max) for NADPH-dependent reduction of cortisone. We conclude that in the testis, caput epididymidis and bulbourethral gland of the immature pig, NADP(+)- and NAD(+)-dependent 11betaHSD enzymes catalyse net inactivation of cortisol, suggesting a physiological role for these enzymes in limiting local actions of glucocorticoids within these male reproductive tissues prior to puberty.


Assuntos
11-beta-Hidroxiesteroide Desidrogenase Tipo 1 , 11-beta-Hidroxiesteroide Desidrogenase Tipo 2 , Genitália Masculina/enzimologia , Isoenzimas , Testículo/enzimologia , 11-beta-Hidroxiesteroide Desidrogenase Tipo 1/genética , 11-beta-Hidroxiesteroide Desidrogenase Tipo 1/metabolismo , 11-beta-Hidroxiesteroide Desidrogenase Tipo 2/genética , 11-beta-Hidroxiesteroide Desidrogenase Tipo 2/metabolismo , Animais , Genitália Masculina/citologia , Glucocorticoides/metabolismo , Isoenzimas/genética , Isoenzimas/metabolismo , Masculino , Suínos , Testículo/citologia , Distribuição Tecidual
7.
Reproduction ; 136(6): 725-32, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18787080

RESUMO

Recent reports have shown that glucocorticoids can modulate oocyte maturation in both teleost fish and mammals. Within potential target cells, the actions of physiological glucocorticoids are modulated by 11beta-hydroxysteroid dehydrogenase (HSD11B) isoenzymes that catalyse the interconversion of cortisol and cortisone. Hence, the objective of this study was to establish whether HSD11B enzymes mediate cortisol-cortisone metabolism in porcine oocytes and, if so, whether the rate of glucocorticoid metabolism changes during oocyte maturation. Enzyme activities were measured in cumulus-oocyte complexes (COCs) and denuded oocytes (DOs) using radiometric conversion assays. While COCs and DOs oxidised cortisol to inert cortisone, there was no detectable regeneration of cortisol from cortisone. The rate of cortisol oxidation was higher in expanded COCs than in compact COCs containing germinal vesicle (GV) stage oocytes (111+/-6 vs 2041+/-115 fmol cortisone/oocyte.24 h; P<0.001). Likewise, HSD11B activities were 17+/-1 fold higher in DOs from expanded COCs than in those from compact COCs (P<0.001). When GV stage oocytes were subject to a 48 h in vitro maturation protocol, the enzyme activities were significantly increased from 146+/-18 to 1857+/-276 fmol cortisone/oocyte.24 h in GV versus MII stage oocytes respectively (P<0.001). Cortisol metabolism was inhibited by established pharmacological inhibitors of HSD11B (glycyrrhetinic acid and carbenoxolone), and by porcine follicular and ovarian cyst fluid. We conclude that an HSD11B enzyme (or enzymes) functions within porcine oocytes to oxidise cortisol, and that this enzymatic inactivation of cortisol increases during oocyte maturation.


Assuntos
11-beta-Hidroxiesteroide Desidrogenases/metabolismo , Glucocorticoides/metabolismo , Isoenzimas/metabolismo , Meiose/fisiologia , Oócitos/citologia , Oócitos/metabolismo , Animais , Carbenoxolona/farmacologia , Células Cultivadas , Cortisona/metabolismo , Feminino , Líquido Folicular/enzimologia , Ácido Glicirretínico/farmacologia , Hidrocortisona/metabolismo , Meiose/efeitos dos fármacos , Oócitos/efeitos dos fármacos , Suínos
8.
Hum Reprod Update ; 14(5): 497-517, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18552168

RESUMO

BACKGROUND: Despite extensive studies of the developmental consequences of increased glucocorticoid exposure in mid- to late pregnancy, relatively little is known regarding the significance of glucocorticoids in early pregnancy. The objective of this review was to consider potential roles for this family of corticosteroids that might relate to early pregnancy. METHODS: Although this is a narrative review, 249 source articles addressing potential effects of glucocorticoids on aspects of early pregnancy and development (published between 1997 and 2007) were identified using a systematic literature search. Additional articles (115) were identified if cited by the primary reference articles identified in the systematic phase of the review. RESULTS: Much of the evidence to implicate glucocorticoids in early pregnancy comes from studies of steroid receptors and the 11beta-hydroxysteroid dehydrogenase enzymes, which modulate cortisol action in the endometrium/decidua, trophoblast, placenta and embryo/fetus. The evidence reviewed suggests that in early pregnancy the actions of glucocorticoids are balanced between positive effects that would promote pregnancy (e.g. stimulation of hCG secretion, suppression of uterine natural killer cells, and promotion of trophoblast growth/invasion) versus adverse effects that would be expected to compromise the pregnancy (e.g. inhibition of cytokine-prostaglandin signalling, restriction of trophoblast invasion following up-regulation of plasminogen activation inhibitor-1, induction of apoptosis, and inhibition of embryonic and placental growth). CONCLUSIONS: Glucocorticoids exert many actions that could impact both negatively and positively on key aspects of early pregnancy. These steroids may also be implicated in obstetric complications, including intra-uterine growth restriction, pre-term labour, pre-eclampsia and chorio-aminionitis.


Assuntos
Glucocorticoides/fisiologia , Gravidez/metabolismo , 11-beta-Hidroxiesteroide Desidrogenases/fisiologia , Animais , Gonadotropina Coriônica/metabolismo , Decídua/metabolismo , Implantação do Embrião , Desenvolvimento Embrionário/efeitos dos fármacos , Feminino , Fertilização in vitro , Glucocorticoides/farmacologia , Humanos , Imunossupressores/farmacologia , Isoenzimas/fisiologia , Troca Materno-Fetal , Placenta/anatomia & histologia , Placenta/metabolismo , Placenta/fisiologia , Gravidez/efeitos dos fármacos , Complicações na Gravidez/induzido quimicamente , Complicações na Gravidez/metabolismo , Trofoblastos/citologia , Trofoblastos/metabolismo
9.
Reproduction ; 134(3): 473-82, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17709565

RESUMO

11Beta-hydroxysteroid dehydrogenase (11betaHSD) enzymes modulate the target cell actions of corticosteroids by catalysing metabolism of the physiological glucocorticoid (GC), cortisol, to inert cortisone. Recent studies have implicated GCs in boar sperm apoptosis. Hence, the objective of this study was to characterise 11betaHSD enzyme expression and activities in the boar testis and reproductive tract. Although 11betaHSD1 and 11betaHSD2 mRNA transcripts and proteins were co-expressed in all tissues, cortisol-cortisone interconversion was undetectable in the corpus and cauda epididymides, vas deferens, vesicular and prostate glands, irrespective of nucleotide cofactors. In contrast, homogenates of boar testis, caput epididymidis and bulbourethral gland all displayed pronounced 11betaHSD activities in the presence of NADPH/NADP(+) and NAD(+), and the penile urethra exhibited NAD(+)-dependent 11beta-dehydrogenase activity. In kinetic studies, homogenates of boar testis, caput epididymidis and bulbourethral gland oxidised cortisol with K(m) values of 237-443 and 154-226 nmol/l in the presence of NADP(+) and NAD(+) respectively. Maximal rates of NADP(+)-dependent cortisol oxidation were 7.4- to 28.5-fold greater than the V(max) for NADPH- dependent reduction of cortisone, but were comparable with the rates of NAD(+)-dependent cortisol metabolism. The relatively low K(m) estimates for NADP(+) -dependent cortisol oxidation suggest that either the affinity of 11betaHSD1 has been increased or the cortisol inactivation is catalysed by a novel NADP(+)-dependent 11betaHSD enzyme in these tissues. We conclude that in the boar testis, caput epididymidis and bulbourethral gland, NADP(+)- and NAD(+)-dependent 11betaHSD enzymes catalyse net inactivation of cortisol, consistent with a physiological role in limiting any local actions of GCs within these reproductive tissues.


Assuntos
11-beta-Hidroxiesteroide Desidrogenases/análise , Genitália Masculina/enzimologia , Glucocorticoides/fisiologia , Sus scrofa/metabolismo , 11-beta-Hidroxiesteroide Desidrogenase Tipo 1/análise , 11-beta-Hidroxiesteroide Desidrogenase Tipo 1/genética , 11-beta-Hidroxiesteroide Desidrogenase Tipo 2/análise , 11-beta-Hidroxiesteroide Desidrogenase Tipo 2/genética , 11-beta-Hidroxiesteroide Desidrogenases/genética , Animais , Sequência de Bases , Western Blotting/métodos , Glândulas Bulbouretrais/enzimologia , Cortisona/metabolismo , Epididimo/enzimologia , Hidrocortisona/metabolismo , Imuno-Histoquímica , Masculino , Dados de Sequência Molecular , NAD/metabolismo , NADP/metabolismo , Reação em Cadeia da Polimerase/métodos , Testículo/enzimologia
10.
Reproduction ; 133(6): 1149-58, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17636169

RESUMO

This study investigated cortisol inactivation by 11beta-hydroxysteroid dehydrogenase (11beta HSD) enzymes in porcine granulosa cells from antral follicles at different developmental stages and in ovarian cysts. In granulosa cells, cortisol oxidation increased threefold with antral follicle diameter (P < 0.001). This trend was paralleled by a threefold increase in NADP(+)-dependent 11beta-dehydrogenase activity in granulosa cell homogenates with follicle diameter. Intact granulosa cells from ovarian cysts exhibited significantly lower enzyme activities than cells from large antral follicles. Neither intact cells norcell homogenates displayed net 11-ketosteroid reductase activities. Since porcine follicular fluid (FF) from large antral follicles and ovarian cysts contains hydrophobic inhibitors of glucocorticoid metabolism by type 1 11beta HSD, this studyalso investigated whether levels of 11beta HSD inhibitors changed during follicle growth and could affect cortisol metabolism in granulosa cells. The extent of inhibition of 11beta HSD1 activity in rat kidney homogenates decreased progressively from 50 +/- 8% inhibition by FF from small antral follicles (P < 0.001) to 23 +/- 6% by large antral FF (P < 0.05). Cyst fluid inhibited 11beta HSD1 activity by 59 +/- 4% (P < 0.001). Likewise, net cortisol oxidation in granulosa cells was significantly decreased by large antral FF (35-48% inhibition, P < 0.05) and cyst fluid (45-75% inhibition, P < 0.01). We conclude that inactivation of cortisol by 11beta HSD enzymes in porcine granulosa cells increases with follicle development but is significantly decreased in ovarian cysts. Moreover, changes in ovarian cortisol metabolism are accompanied by corresponding changes in the levels of paracrine inhibitors of 11beta HSD1 within growing ovarian follicles and cysts, implicating cortisol in follicle growth and cyst development.


Assuntos
11-beta-Hidroxiesteroide Desidrogenases/metabolismo , Hidrocortisona/metabolismo , Cistos Ovarianos/metabolismo , Folículo Ovariano/fisiologia , Sus scrofa/metabolismo , 11-beta-Hidroxiesteroide Desidrogenase Tipo 1/metabolismo , Animais , Bioensaio , Feminino , Células da Granulosa/metabolismo , Rim/metabolismo , Cistos Ovarianos/veterinária , Oxirredução , Ratos
11.
Endocrinology ; 147(12): 5865-72, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16959838

RESUMO

11beta-hydroxysteroid dehydrogenase (11betaHSD) enzymes regulate glucocorticoid availability in target tissues. 11betaHSD1 is the predominant isoenzyme expressed and active in human granulosa-lutein (hGL) cells. This study investigated the effects of pharmacological inhibitors of prostaglandin (PG) synthesis on 11betaHSD1 activities and expression in hGL cells. The consequences for 11betaHSD1 of increasing exposure of hGL cells to PGs, either by treatment with exogenous PGs or by challenging cells with IL-1beta, were also assessed. Suppression of basal PG synthesis using four different inhibitors of PG H synthase enzymes [indomethacin, niflumic acid, meclofenamic acid (MA) and N-(2-cyclohexyloxy-4-nitorophenyl) methane sulfonamide (NS-398)] each resulted in significant decreases in both cortisol oxidation and cortisone reduction. Both activities of 11betaHSD1 were suppressed by up to 64+/-6% (P<0.05). Over 4 and 24 h, neither MA nor NS-398 affected the expression of 11betaHSD1 protein, suggesting enzyme regulation by PGs at the posttranslational level. When cells were cotreated for 4 h with PGHS inhibitors plus 30 nm PGD2, PGF2alpha, or PGE2, each PG overcame the suppression of cortisol oxidation by indomethacin or MA. Treatment of hGL cells with IL-1beta increased the concentrations of both PGE2 and PGF2alpha, accompanied by a 70+/-25% increase in net cortisol oxidation. All three responses to IL-1beta were abolished when cells were cotreated with MA. These findings suggest a role for PGs in the posttranslational regulation of 11betaHSD1 activities in hGL cells.


Assuntos
11-beta-Hidroxiesteroide Desidrogenases/metabolismo , Células Lúteas/enzimologia , Prostaglandinas/fisiologia , Células Cultivadas , Inibidores de Ciclo-Oxigenase/farmacologia , Feminino , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Humanos , Interleucina-1beta/farmacologia , Ácido Meclofenâmico/farmacologia , Modelos Biológicos , Nitrobenzenos/farmacologia , Prostaglandina-Endoperóxido Sintases/metabolismo , Prostaglandinas/biossíntese , Prostaglandinas/farmacologia , Sulfonamidas/farmacologia
12.
Mol Cell Endocrinol ; 222(1-2): 1-8, 2004 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-15249120

RESUMO

In human granulosa-lutein cells, high-density lipoproteins (HDL) can stimulate progesterone synthesis. The objective of the present study was to establish whether prostaglandins (PGs) participate in the steroidogenic response to HDL. Both HDL and apolipoprotein AI (ApoAI) stimulated concentration-dependent increases in PGE2, cAMP and progesterone accumulation. The minimum concentrations of HDL and ApoAI required to elevate PGE2 production were the same as those required to stimulate cAMP accumulation and progesterone synthesis. Concentrations of PGE2 were elevated within 10 min in cells exposed to HDL and rose progressively over 24 h, whereas cAMP and progesterone were only increased significantly after 24 h of treatment with HDL. Co-treatment with prostaglandin H synthase inhibitors (meclofenamic acid and indomethacin) abolished the cAMP and progesterone responses to both HDL and ApoAI. Hence, the ability of HDL to stimulate progesterone synthesis can be mimicked by ApoAI and appears to involve increased generation of one or more luteotrophic PGs, possibly acting via cAMP.


Assuntos
AMP Cíclico/metabolismo , Dinoprostona/metabolismo , Células da Granulosa/efeitos dos fármacos , Lipoproteínas HDL/farmacologia , Células Lúteas/metabolismo , Progesterona/metabolismo , Apolipoproteína A-I/farmacologia , Ciclo-Oxigenase 1 , Relação Dose-Resposta a Droga , Feminino , Células da Granulosa/metabolismo , Humanos , Isoenzimas/antagonistas & inibidores , Células Lúteas/efeitos dos fármacos , Proteínas de Membrana , Prostaglandina-Endoperóxido Sintases , Fatores de Tempo
13.
Reproduction ; 126(4): 425-41, 2003 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-14525525

RESUMO

Within potential target cells, the actions of physiological glucocorticoids (cortisol and corticosterone) are modulated by isoforms of the enzyme 11 beta-hydroxysteroid dehydrogenase (11 beta HSD). To date, two isoforms of 11 beta HSD have been cloned: 11 beta HSD1 acts predominantly as an NADP(H)-dependent reductase to generate active cortisol or corticosterone, and 11 beta HSD2 is a high affinity NAD(+)-dependent enzyme that catalyses the enzymatic inactivation of glucocorticoids. Whereas the regeneration of active glucocorticoids by 11 beta HSD1 has been implicated in the cellular mechanisms of pituitary function, ovulation and parturition, the enzymatic inactivation of cortisol and corticosterone by 11 beta HSD enzymes appears to be central to the protection of gonadal steroidogenesis, prevention of intra-uterine growth retardation, and lactation. Recent evidence indicates that follicular fluid contains endogenous modulators of cortisol metabolism by 11 beta HSD1, the concentrations of which are associated with the clinical outcome of assisted conception cycles and are altered in cystic ovarian disease. In conclusion, the two cloned isoforms of 11 beta HSD fulfil diverse roles in a wide range of reproductive processes from conception to lactation.


Assuntos
Glucocorticoides/metabolismo , Isoenzimas/metabolismo , Reprodução/fisiologia , 11-beta-Hidroxiesteroide Desidrogenases/metabolismo , Animais , Corticosterona/metabolismo , Desenvolvimento Embrionário e Fetal , Feminino , Fertilização in vitro , Retardo do Crescimento Fetal/enzimologia , Humanos , Hidrocortisona/metabolismo , Hipotálamo/enzimologia , Trabalho de Parto , Masculino , Glândulas Mamárias Animais/enzimologia , Ovário/enzimologia , Adeno-Hipófise/enzimologia , Gravidez , Espermatozoides/enzimologia , Testículo/enzimologia , Útero/enzimologia
14.
J Steroid Biochem Mol Biol ; 84(1): 71-8, 2003 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-12648526

RESUMO

Ovarian steroids appear to influence the manifestations of sickle cell disease (SCD); oestrogens can adversely affect erythrocyte function, whereas progestogens may inhibit sickling and decrease the osmotic fragility of erythrocytes. The aims of the present studies were: (i) to characterise the binding of oestradiol and progesterone to erythrocytes from women with HbSS, HbSC and HbAA genotypes; (ii) to investigate whether steroids modulate susceptibility to sickling or osmotic fragility of HbSS and HbAA erythrocytes. Erythrocytes were incubated for 1h with [3H]-steroids at 4 and 37 degrees C. Binding of both oestradiol and progesterone was independent of temperature and steroid concentration, but was decreased by sequential "washing" of erythrocytes in fresh incubation buffer. Binding capacity was 80 +/- 6% greater for oestradiol (versus progesterone) in all three genotypes, and binding of both steroids was decreased by > or = 70% in HbSS erythrocytes compared to HbSC or HbAA erythrocytes. Pre-incubation of erythrocytes with 35 microM oestradiol or 30 microM progesterone had no significant effect on susceptibility of HbSS and HbAA erythrocytes to sickling, or on osmotic fragility. We conclude that both oestradiol and progesterone bind in a low affinity, non-saturable manner to erythrocytes with decreased binding in cells from women with HbSS. However, steroid binding does not affect susceptibility to sickling or osmotic fragility irrespective of haemoglobin genotype.


Assuntos
Anemia Falciforme/metabolismo , Eritrócitos/metabolismo , Estradiol/metabolismo , Ovário/metabolismo , Progesterona/metabolismo , Adulto , Relação Dose-Resposta a Droga , Feminino , Genótipo , Hemoglobina A/metabolismo , Doença da Hemoglobina SC/metabolismo , Hemoglobina Falciforme/metabolismo , Hemoglobinas/genética , Hemoglobinas/metabolismo , Humanos , Osmose , Ligação Proteica , Temperatura , Fatores de Tempo
15.
Biol Reprod ; 68(6): 2157-63, 2003 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12606327

RESUMO

In the ovary, cortisol is oxidized to cortisone by 11beta-hydroxysteroid dehydrogenase (11betaHSD). The present study investigated whether follicular fluid (FF) from large antral follicles and spontaneous ovarian cysts, isolated from bovine and porcine ovaries, contained modulators of 11betaHSD activity. Whereas FF from antral follicles had no significant effect over 1 h on NADP+-dependent 11betaHSD activity in rat kidney homogenates, enzyme activity was inhibited by FF from bovine and porcine ovarian cysts (80.5% +/- 2.3% and 72.8% +/- 3.4% of control, respectively). Following C18 reverse-phase chromatography, the hydrophilic fractions of FF from bovine and porcine antral follicles stimulated NADP+-dependent 11betaHSD activities (111.5% +/- 21.6% and 55.2% +/- 5.7% respectively). Hydrophobic compounds inhibited NADP+-dependent cortisol oxidation by 58.2% +/- 5.1% (bovine) and 45.7% +/- 2.0% (porcine). In both species, FF from ovarian cysts appeared to contain less of the hydrophilic stimuli to 11betaHSD activity and more of the hydrophobic inhibitors. The FF from antral follicles and ovarian cysts, and the C18 fractions thereof, had no significant effect on NAD+-dependent cortisol oxidation. The ovarian modulators of NADP+-dependent 11betaHSD activities did not coelute with cortisol, cortisone, estradiol, testosterone, progesterone, pregnenolone, and cholesterol. However, the 11betaHSD stimuli in porcine FF from both antral follicles and cysts coeluted with prostaglandin (PG) E2 and PGF2alpha. We conclude that large antral follicles and spontaneous ovarian cysts, in both the cow and the pig, contain ovarian modulators of the NADP+-dependent 11betaHSD activity. Moreover, FF from spontaneous ovarian cysts, because of decreased content of the 11betaHSD stimulus accompanied by increased content of the 11betaHSD inhibitors, exerts a net inhibitory effect on 11betaHSD activity.


Assuntos
11-beta-Hidroxiesteroide Desidrogenases/metabolismo , Líquido Folicular/enzimologia , Cistos Ovarianos/enzimologia , Folículo Ovariano/enzimologia , Ovário/fisiologia , Animais , Bovinos , Feminino , Hormônios Esteroides Gonadais/fisiologia , Hidrocortisona/metabolismo , Rim/enzimologia , NAD/fisiologia , NADP/fisiologia , Oxirredução , Suínos
16.
Reprod Biomed Online ; 7(6): 683-90, 2003 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-14748968

RESUMO

Previous studies have reported both direct and indirect evidence correlating the probability of conception by IVF-embryo transfer with follicular metabolism of glucocorticoids by the enzyme 11 beta-hydroxysteroid dehydrogenase (11 betaHSD). To resolve disputes regarding the predictive value of measures of cortisol-cortisone interconversion, this study has focused on compounds present in follicular fluid that can regulate enzyme activities within the ovary. Follicular fluid contains both hydrophilic compounds that can stimulate and hydrophobic components that can inhibit the oxidation of cortisol to cortisone by 11 betaHSD. These latest data indicate that: (i) cortisol:cortisone ratios in follicular fluid increase in proportion to the follicular content of the hydrophobic inhibitors of 11 betaHSD (r2 = 0.076; P < 0.01); (ii) the developmental potential of the oocyte and embryo, in terms of the probability of conception subsequent to embryo transfer, is positively correlated with follicular cortisol:cortisone ratios (12.9 +/- 0.3 in conception cycles versus 8.5 +/- 0.2 in non-conception cycles, P < 0.0001; odds ratio = 3364.48, P < 0.001); (iii) conception by IVF-embryo transfer is associated with increased concentrations of the ovarian inhibitors of 11 betaHSD (odds ratio = 4.54, P < 0.01) but with decreased concentrations of the ovarian stimuli of 11 betaHSD (odds ratio = 0.18, P < 0.001).


Assuntos
Fertilização in vitro , Fertilização/fisiologia , Hidrocortisona/sangue , 11-beta-Hidroxiesteroide Desidrogenases/metabolismo , Transferência Embrionária , Feminino , Humanos , Ovário/fisiologia , Gravidez , Resultado da Gravidez
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