RESUMO
Biotransformation of viridin, an antifungal produced by biocontrol agent, with non-viridin producing microorganisms is studied. The results show that some environmental non-targeted microorganisms are able to reduce it in the known phytotoxin viridiol, and its 3-epimer. Consequently, this reduction, which happens in some cases by detoxification mechanism, could be disastrous for the plant in a biocontrol of plant disease. However, a process fermentation/biotransformation could be an efficient approach for the preparation of this phytotoxin.
Assuntos
Androstenodióis/farmacologia , Androstenos/farmacologia , Antifúngicos/farmacologia , Bacteriocinas/farmacologia , Hypocrea/efeitos dos fármacos , Androstenodióis/química , Androstenodióis/metabolismo , Androstenos/química , Androstenos/metabolismo , Antifúngicos/química , Antifúngicos/metabolismo , Bacteriocinas/química , Bacteriocinas/metabolismo , Biotransformação , Relação Dose-Resposta a Droga , Fermentação/efeitos dos fármacos , Hypocrea/metabolismo , Testes de Sensibilidade Microbiana , Estrutura Molecular , Relação Estrutura-AtividadeRESUMO
Prior studies have given no evidence for regulation of vitamin D receptor (VDR) compartmentalization or subcellular organization. Microwave fixation (9-15 s) and an indirect immunodetection system of avidin-biotin enhancement and phycoerythrin fluorophore resulted in sufficient spatial and temporal resolution to allow analysis of these processes. We studied cultured fibroblasts from normals or from patients with four different types of hereditary defect compromising VDR function (mutant cells). Compartmentalization of VDRs in the absence of 1,25-dihydroxyvitamin D3 (calcitriol) was regulated by serum or estrogen. VDRs were mainly cytoplasmic in cells cultured without serum and phenol red, but VDRs were mainly intranuclear after addition of serum or an estrogen to cells for at least 18 h (slow regulation). Calcitriol initiated a rapid and multistep process (rapid regulation) of reorganization in a portion of VDRs: clumping within 15-45 s, alignment of clumps along fibrils within 30-45 s, perinuclear accumulation of clumps within 45-90 s, and intranuclear accumulation of clumps within 1-3 min. We found similar rapid effects of calcitriol on VDRs in various other types of cultured cells. These sequential VDR pattern changes showed calcitriol dose dependency and calcitriol analogue specificity characteristic for the VDR. In mutant fibroblasts VDR pattern changes after calcitriol were absent or severely disturbed at selected steps. Treatment of normal cells with wheat germ agglutinin, which blocks protein transport through nuclear pores, also blocked calcitriol-dependent translocation of VDRs. We conclude that immunocytology after microwave fixation provides evidence for regulation of VDR organization and localization.
Assuntos
Calcitriol/farmacologia , Dietilestilbestrol/farmacologia , Estradiol/farmacologia , Micro-Ondas , Receptores de Esteroides/metabolismo , Pele/metabolismo , Androstenodióis/farmacologia , Animais , Calcitriol/metabolismo , Linhagem Celular , Células Cultivadas , DNA/metabolismo , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Humanos , Imuno-Histoquímica , Progesterona/farmacologia , Receptores de Calcitriol , Receptores de Esteroides/efeitos dos fármacosRESUMO
Stimulation of prostate growth is a major concern with testosterone therapy in older hypogonadal men. As a result, nonsteroidal selective androgen receptor modulators with anabolic activity but less prostate stimulation are being developed. Anabolic steroids might exhibit similar tissue selectivity. We hypothesized the anabolic steroid 19-nor-4-androstenediol-3beta,17beta-diol (3beta,19-NA) would increase muscle, lean body mass (LBM), and bone mineral density (BMD) with little stimulation of prostate growth. Male Sprague Dawley rats were implanted with SILASTIC brand (Dow Corning, Midland, MI) capsules containing 3beta,19-NA (4, 8, or 16 cm), dihydrotestosterone (DHT) (8 cm), 19-nortestosterone (16 cm), or four empty capsules after undergoing either a sham operation (intact) or orchidectomy (ORX). Serum gonadotropins, measured after 4, 8, or 24 wk of treatment, were significantly lower in 3beta,19-NA-treated vs. untreated, intact, and ORX rats (P < 0.05), and testosterone was lowered by 3beta,19-NA-treatment of intact animals. LBM and BMD were assessed after 20 wk, and 4 wk later, rats were killed for levator ani muscle and prostate weights. Compared with ORX rats, 3beta,19-NA-treated rats had dose-dependent higher levator ani muscle weights, LBM, and BMD, which were similar to intact and DHT-treated rats at the highest 3beta,19-NA dose. In contrast, prostate weights in all 3beta,19-NA-treated groups were similar to ORX rats and lower than intact and DHT- and 19-nortestosterone-treated rats even at the highest 3beta,19-NA dose. In summary, 3beta,19-NA increases muscle and bone mass without significant stimulation of prostate growth, suggesting it may have some properties of a steroidal selective androgen receptor modulator. Anabolic steroids such as 3beta,19-NA should be studied further to determine their mechanisms of tissue selectivity and effects in men.
Assuntos
Androstenodióis/farmacologia , Densidade Óssea/efeitos dos fármacos , Músculo Esquelético/efeitos dos fármacos , Próstata/efeitos dos fármacos , Animais , Composição Corporal/efeitos dos fármacos , Sistema Hipotálamo-Hipofisário/efeitos dos fármacos , Masculino , Especificidade de Órgãos , Ratos , Ratos Sprague-DawleyRESUMO
A large body of evidence suggests that the immune system directly impacts bone physiology. We tested whether immune regulating hormones (IRH), 17beta-androstenediol (beta-AED), 7beta,17beta-androstenetriol (beta-AET) or the 17alpha-androstenediol (alpha-AED), and 7alpha,17beta-androstenetriol (alpha-AET) metabolites could directly influence bone remodeling in vitro using human fetal osteoblasts (FOB-9). The impact on bone remodeling was examined by comparing the ratio of RANKL/OPG gene expression in response to AED and AET compounds. The alpha-AED was found to significantly increase in the ratio of RANKL/OPG gene expression and altering the morphology of RANKL stained FOB-9 cells. Cell viability was assessed using a Live/Dead assay. Again alpha-AED was unique in its ability to reduce the proportion of viable cells, and to induce mild apoptosis of FOB-9 cells. Treatment of FOB-9 cells with WY14643, an activator of PPAR-alpha and -gamma, also significantly elevated the percentage of dead cells. This increase was abolished by co-treatment with GW9962, a specific inhibitor of PPAR-gamma. Analysis of PPAR-gamma mRNA by Quantitative RT-PCR and its activation by DNA binding demonstrated that alpha-AED increased PPAR-gamma activation by 19%, while beta-AED conferred a 37% decrease in PPAR-gamma activation. In conclusion, alpha-AED opposed beta-AED by elevating a bone resorption scenario in osteoblast cells. The increase in RANKL/OPG is modulated by an activation of PPAR-gamma that in turn caused mild apoptosis of FOB-9 cells.
Assuntos
Androstenodióis/farmacologia , Apoptose/efeitos dos fármacos , Remodelação Óssea/efeitos dos fármacos , Sistema Imunitário/efeitos dos fármacos , Osteoblastos/efeitos dos fármacos , Androstenóis/química , Androstenóis/farmacologia , Remodelação Óssea/imunologia , Reabsorção Óssea/genética , Forma Celular/efeitos dos fármacos , Células Cultivadas , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Sistema Imunitário/fisiologia , Osteoblastos/citologia , Osteoblastos/metabolismo , Osteoprotegerina/genética , Osteoprotegerina/metabolismo , PPAR gama/genética , PPAR gama/metabolismo , Ligante RANK/genética , Ligante RANK/metabolismoRESUMO
Aldosterone receptors from rat kidney slices were utilized in a competitive binding technique to analyze the contribution of various steroids to plasma "mineralocorticoid" activity and to assess their possible role in hypertension. To consider simultaneously the plasma binding, steroids were incubated with slices in undiluted plasma; competitor activities for [3H]aldosterone binding were aldosterone, 100%; deoxycorticosterone, 16.2%; cortisol, 0.4%; and 18-hydroxy-deoxy-corticosterone and d18-hydroxy-corticosterone, 0.1%. These steroids were more active in buffer than plasma, suggesting that they bind to plasma and that this reduces their receptor binding. Analysis of the competition data suggests that at normal plasma concentrations, aldosterone occupies the receptors to a major extent, cortisol occupies some of the receptors, and deoxycorticosterone and 8-hydroxydeoxycorticosterone contribute little to receptor occupancy. Two steroids implicated in low-renin essential hypertension, 16beta-hydroxy-dehydro-epiandrosterone and 16-oxoandrostenediol, did not have significant competitor activity. Competitor activity in plasmas from normal subjects taken at 12 noon (upright) was greater than that in those taken at 8 a.m. (supine). Since the 12 noon samples had higher aldosterone and lower cortisol levels than the 8 a.m. samples, the competitor activity under these physiological circumstances reflects aldosterone more than cortisol. The competitor activities of plasmas from patients relative to normal subjects (100+/-12.1%; mean+/-SEM) were: normal renin "essential" hypertension, 117+/-14%; low-renin essential hypertension, 101+/-6.6%; and primary aldosteronism, 176+/-14.3%. Thus a significant increase in activity of steroids that interact with mineralocorticoid receptors was detected in primary aldosteronism (P LESS THAN 0.01) BUT WAS NOT DETECTED IN LOW-RENIN OR NORMAL-RENIN ESSENTIAL HYPERTENSION.
Assuntos
Aldosterona/metabolismo , Hipertensão/sangue , Mineralocorticoides/sangue , Receptores de Superfície Celular , Androstenodióis/sangue , Androstenodióis/farmacologia , Animais , Ligação Competitiva , Corticosterona/análogos & derivados , Corticosterona/sangue , Corticosterona/farmacologia , Depressão Química , Desoxicorticosterona/sangue , Desoxicorticosterona/farmacologia , Hidrocortisona/sangue , Hidrocortisona/farmacologia , Postura , Ratos , Fatores de TempoRESUMO
Testosterone prohormones such as androstenedione, androstenediol, and dehydroepiandrosterone (DHEA) have been heavily marketed as testosterone-enhancing and muscle-building nutritional supplements for the past decade. Concerns over the safety of prohormone supplement use prompted the United States Food and Drug Administration to call for a ban on androstenedione sales, and Congress passed the Anabolic Steroid Control Act of 2004, which classifies androstenedione and 17 other steroids as controlled substances. As of January 2005, these substances cannot be sold without prescription. Here, we summarize the current scientific knowledge regarding the efficacy and safety of prohormone supplementation in humans. We focus primarily on androstenedione, but we also discuss DHEA, androstenediol, 19-nor androstenedione, and 19-nor androstenediol supplements. Contrary to marketing claims, research to date indicates that the use of prohormone nutritional supplements (DHEA, androstenedione, androstenediol, and other steroid hormone supplements) does not produce either anabolic or ergogenic effects in men. Moreover, the use of prohormone nutritional supplements may raise the risk for negative health consequences.
Assuntos
Androstenodióis/farmacologia , Androstenodiona/farmacologia , Desidroepiandrosterona/farmacologia , Dopagem Esportivo , Androstenodióis/efeitos adversos , Androstenodiona/efeitos adversos , Desidroepiandrosterona/efeitos adversos , Dopagem Esportivo/legislação & jurisprudência , Controle de Medicamentos e Entorpecentes , Humanos , Detecção do Abuso de Substâncias , Estados UnidosRESUMO
A novel furanosteroid named 9-epi-viridiol (1), along with viridiol (2) and mevalonic acid (3), was isolated from Trichoderma virens. The structure of 1 was verified by combined spectroscopic data (COSY, HSQC, HMBC and NOESY) to be a C-9 epimer of viridiol. 9-epi-Viridiol exhibited cytotoxicity towards HeLa and KB cells with IC50 values of 19 and 50 microg mL(-1), respectively.
Assuntos
Androstenodióis/química , Antineoplásicos/química , Trichoderma/química , Androstenodióis/isolamento & purificação , Androstenodióis/farmacologia , Antineoplásicos/isolamento & purificação , Antineoplásicos/farmacologia , Ensaios de Seleção de Medicamentos Antitumorais , Formazans , Células HeLa , Humanos , Concentração Inibidora 50 , Células KB , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Rotação Ocular , Espectrofotometria Ultravioleta , Estereoisomerismo , Espectrometria de Massas em Tandem , Sais de Tetrazólio , TailândiaRESUMO
5-Androstene-3 beta, 17 beta-diol (ADIOL) has previously been shown to have a high affinity for the estrogen receptor and to translocate it to the nucleus in vitro and in vivo. This compound and related C19 delta 5-steroids of adrenal origin have now been examined for their ability to induce the synthesis in MCF7 cells of an estrogen-dependent secreted glycoprotein (M.W. 46,000). Concentrations required for half-maximum induction were 2 nM for ADIOL and 500 nM for dehydroepiandrosterone (DHEA). Dehydroepiandrosterone sulfate showed weak inducing ability at concentrations of 1 microM or greater. The induction by ADIOL was unaffected by the presence of an aromatase inhibitor, and 5 alpha-androstane-3 beta, 17 beta-diol, which cannot be aromatized, also induced the M.W. 46,000 protein at low concentrations. When cells were exposed to 10 nM [3H]ADIOL, the cytosol and nuclear fractions contained [3H]ADIOL resistant to charcoal adsorption. The bound [3H]ADIOL in the cytosol and nucleus was displaceable by 17 beta-estradiol and tamoxifen, suggesting that it was binding to the estrogen receptor. [3H]ADIOL was metabolized to its 3 beta-sulfate, which was excreted into the medium, and to [3H]DHEA, which was found in the cells and the medium as free DHEA and its 3 beta-sulfate. [3H]DHEA was also metabolized by the cells to its 3 beta-sulfate, to free ADIOL, and to the 3 beta-sulfate of adiol. We conclude that: (a) ADIOL is effective as an estrogen in MCF7 cells at a concentration of 2 nM, which is within the range found in the blood of normal women; and (b) sulfurylation is a major route of inactivation of 3 beta-hydroxy delta 5-steroids in MCF7 cells.
Assuntos
Androstenodiol/farmacologia , Androstenodióis/farmacologia , Neoplasias da Mama/metabolismo , Receptores de Estrogênio/metabolismo , Androstenodiol/metabolismo , Biotransformação , Linhagem Celular , Núcleo Celular/metabolismo , Citosol/metabolismo , Desidroepiandrosterona/metabolismo , Eletroforese em Gel de Poliacrilamida , Estradiol/sangue , Estrona/sangue , Feminino , Glicoproteínas/biossíntese , HumanosRESUMO
We have examined the effect of androst-5-ene-3 beta,17 beta-diol (delta 5-diol) and its precursors, dehydroepiandrosterone (DHEA) and dehydroepiandrosterone 3 beta-sulfate (DHEAS), on the growth of the estrogen-sensitive human breast cancer cell line, ZR-75-1. While the cell number was increased up to 4-fold by maximal concentrations of estradiol, delta 5-diol maximally stimulated cell proliferation by approximately 3-fold. Since the half-maximal stimulation achieved by delta 5-diol is observed at 2.5 nM and the normal range of plasma concentrations of this steroid in women is 1 to 3 nM, it is most likely that the stimulatory effect of delta 5-diol has physiological significance. DHEA and DHEAS were much less effective than delta 5-diol in stimulating the proliferation of ZR-75-1 cells, the maximal effect on cell number being 75% at the maximal dose used, namely 10 microM. The mitogenic effects of estradiol and delta 5-diol were competitively inhibited by the antiestrogen LY156758 (keoxifene), while the effects of DHEA and DHEAS were completely abolished by the antiestrogen. The effects of DHEA and delta 5-diol on cell proliferation are not likely to be mediated via their conversion to estrone or estradiol, since androstenedione had no effect, while testosterone and dihydrotestosterone decreased cell number by about 20%. The number of specific progesterone binding sites was increased 3.7-, 3.2-, and 2.0-fold by delta 5-diol, DHEA, and DHEAS, respectively. The relative potency of the C19-delta 5-steroids to increase the number of progesterone-specific binding sites was comparable to their ability to stimulate cell proliferation. Direct competition experiments performed with intact cells in monolayer culture showed that, under conditions of minimal metabolism, only delta 5-diol could significantly compete with estradiol for cellular estrogen-specific binding sites with an apparent dissociation constant of 11 nM, thus suggesting that physiological concentrations of C19-delta 5-steroids of adrenal origin could exert an estrogenic stimulation of breast tumor growth without involvement of the aromatase pathway. The present data suggest not only that estrone derived from androstenedione could play a role in estrogen-sensitive breast cancer in women but that delta 5-diol could well be the most important estrogen in breast cancer in women.
Assuntos
Androstenodiol/farmacologia , Androstenodióis/farmacologia , Neoplasias da Mama/patologia , Estrogênios/farmacologia , Divisão Celular/efeitos dos fármacos , Linhagem Celular , Desidroepiandrosterona/análogos & derivados , Desidroepiandrosterona/farmacologia , Sulfato de Desidroepiandrosterona , Estradiol/metabolismo , Antagonistas de Estrogênios/farmacologia , Feminino , Humanos , Receptores de Progesterona/análiseRESUMO
Many neurological and psychiatric maladies originate from the deprivation of the human brain from estrogens. However, current hormone therapies cannot be used safely to treat these conditions commonly associated with menopause because of detrimental side effects in the periphery. The latter also prevents the use of the hormone for neuroprotection. We show that a small-molecule bioprecursor prodrug, 10ß,17ß-dihydroxyestra-1,4-dien-3-one (DHED), converts to 17ß-estradiol in the brain after systemic administration but remains inert in the rest of the body. The localized and rapid formation of estrogen from the prodrug was revealed by a series of in vivo bioanalytical assays and through in vivo imaging in rodents. DHED treatment efficiently alleviated symptoms that originated from brain estrogen deficiency in animal models of surgical menopause and provided neuroprotection in a rat stroke model. Concomitantly, we determined that 17ß-estradiol formed in the brain from DHED elicited changes in gene expression and neuronal morphology identical to those obtained after direct 17ß-estradiol treatment. Together, complementary functional and mechanistic data show that our approach is highly relevant therapeutically, because administration of the prodrug selectively produces estrogen in the brain independently from the route of administration and treatment regimen. Therefore, peripheral responses associated with the use of systemic estrogens, such as stimulation of the uterus and estrogen-responsive tumor growth, were absent. Collectively, our brain-selective prodrug approach may safely provide estrogen neuroprotection and medicate neurological and psychiatric symptoms developing from estrogen deficiency, particularly those encountered after surgical menopause, without the adverse side effects of current hormone therapies.
Assuntos
Androstenodióis/farmacologia , Encéfalo/metabolismo , Estradiol/metabolismo , Estrogênios/metabolismo , Pró-Fármacos/farmacologia , Androstenodióis/uso terapêutico , Animais , Antidepressivos/farmacologia , Antidepressivos/uso terapêutico , Biomarcadores/metabolismo , Encéfalo/efeitos dos fármacos , Isquemia Encefálica/complicações , Isquemia Encefálica/tratamento farmacológico , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/patologia , Proliferação de Células/efeitos dos fármacos , Modelos Animais de Doenças , Estradiol/química , Estrogênios/química , Feminino , Humanos , Células MCF-7 , Neuroproteção/efeitos dos fármacos , Pró-Fármacos/metabolismo , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/tratamento farmacológico , Útero/efeitos dos fármacosRESUMO
delta 5-Androstene-3 beta, 17 beta-diol (Adiol), in a dosage of 1000 microgram/24 h injected ip into immature female Wistar rats (21-23 days old), induced 72 h after the injection the same elevations of uterine weight, cytosol protein, nuclear DNA, cytosol estrogen and progesterone receptors, and nuclear estrogen receptor levels as did 17 beta-estradiol (E2) in a dosage of 2.5 microgram/24 h. Adiol appeared to translocate the estrogen receptor and induce the synthesis of estrogen and progesterone cytosol receptors in a manner almost identical to that of E2. Studies on the metabolism of tritiated Adiol ruled out the possibility that the estrogenic effects of Adiol might be mediated by conversion to E2. Small doses of Adiol (100 microgram), which alone did not result in estrogenic effects, enhanced the effect of 2.5 microgram E2 on uterine weight and progesterone receptor levels, whereas a dosage of 100 microgram dihydrotestosterone neither enhanced nor inhibited the uterine growth induced by 2.5 microgram E2. A role for the androgen receptor in the synergism between Adiol and E2, therefore, appears to be ruled out. When Adiol in a dosage of 1000 microgram was administered together with 2.5 microgram E2, there was no important difference compared to either steroid alone up to 6 h. Thereafter, a very pronounced and prolonged secondary wave of translocation of the E2 receptor to the nucleus occurred which can explain the synergism between E2 and Adiol that became apparent in the same time interval. This secondary wave of translocation is most likely related to the persistent presence of both Adiol and E2 at the time of replenishment of the cytosol receptor (3-6 h after the injection). It is concluded that delta 5-androstene-3 beta, 17 beta-diol acts in the immature rat uterus like a fully potent estrogen with a complete lack of antiestrogenic effects. In this respect it differs from androgens like testosterone and dihydrotestosterone which can display both estrogenic and antiestrogenic activities.
Assuntos
Androstenodiol/farmacologia , Androstenodióis/farmacologia , Estradiol/farmacologia , Útero/metabolismo , Animais , Ligação Competitiva , Núcleo Celular/metabolismo , Citosol/metabolismo , Feminino , Cinética , Tamanho do Órgão/efeitos dos fármacos , Ratos , Receptores de Estrogênio/metabolismo , Receptores de Progesterona/metabolismo , Útero/efeitos dos fármacosRESUMO
As part of our investigation into the structure-activity relationship of a novel class of aromatase inhibitors, C(19) steroids having no oxygen function at C-3, we tested aromatase inhibition activity of polar diol compounds 4,19-dihydroxyandrost-5-en-17-ones (25 and 27) and 6,19-dihydroxyandrost-4-en-17-ones (36 and 37). 4alpha,19-Diol 25 was synthesized from tert-butyldimethylsilyoxyandrost-4-ene steroid (9) through its OsO(4) oxidation, giving the 4alpha,5alpha-dihydroxy derivative 12, as a key reaction. Acetylation of 5beta,6alpha-dihydroxy-19-acetate 30 and its 5alpha,6beta-analogue 31 followed by dehydration with SOCl(2) and alkaline hydroxysis gave 6alpha,19-diol 36 and its 6beta-isomer 37, respectively. The stereochemistry of a hydroxy group at C-4 of compound 25 and that at C-6 of compounds 36 and 37 were determined on the basis of (1)H NMR spectroscopy in each case. 4beta,19-Diol 27, previously synthesized, was identified as an extremely powerful competitive inhibitor of aromatase (K(i) = 3.4 nM). In contrast, its 4alpha,19-dihydroxy isomer 25 and other series of diol compounds, 6,19-dihydroxy-4-en-17-one steroids, were moderate to poor competitive inhibitors (K(i) = 110-800 nM). Through this series of analyses, it was concluded that hydrophilic interaction of a 4beta,19-diol function with the active site of aromatase plays a critical role in the tight binding of 3-deoxy-5-ene steroids.
Assuntos
Androstenodióis/síntese química , Aromatase/metabolismo , Inibidores Enzimáticos/síntese química , Androstenodióis/química , Androstenodióis/metabolismo , Androstenodióis/farmacologia , Inibidores da Aromatase , Sítios de Ligação , Inibidores Enzimáticos/química , Inibidores Enzimáticos/metabolismo , Inibidores Enzimáticos/farmacologia , Feminino , Humanos , Hidroxilação , Técnicas In Vitro , Microssomos/efeitos dos fármacos , Microssomos/enzimologia , Placenta/enzimologia , Placenta/ultraestrutura , Ligação Proteica , Relação Estrutura-AtividadeRESUMO
The induction of intranasal tolerance might be dependent on specific characteristics of mucosal, nose-draining lymph nodes. Such a specific characteristic might lie in the metabolism of the steroid hormone DHEA. Conversion of the prohormone DHEAS into DHEA is dependent on DHEAS-sulphatase activity in lymph nodes. This activity is low in mucosa-draining lymph nodes compared to peripheral lymph nodes, leading to differences in microenvironment. However, administration of DHEA before the induction of intranasal tolerance, could not change tolerance induction. We next determined the effect of DHEA after the induction of intranasally induced tolerance and demonstrated that the steroid hormone and some of its derivatives are able to break tolerance, when administered at time of systemic immunization. These findings might have implications for the regulation of intranasal tolerance and the use of DHEA.
Assuntos
Desidroepiandrosterona/imunologia , Desidroepiandrosterona/farmacologia , Hipersensibilidade Tardia/imunologia , Tolerância Imunológica/efeitos dos fármacos , Imunização , Administração Intranasal , Androstenodióis/imunologia , Androstenodióis/farmacologia , Androstenóis/imunologia , Androstenóis/farmacologia , Animais , Anticorpos/sangue , Formação de Anticorpos/imunologia , Desidroepiandrosterona/análogos & derivados , Hipersensibilidade Tardia/terapia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Ovalbumina/imunologia , Ovalbumina/farmacologiaRESUMO
The effects on sodium transport of several steroids physiologically secreted or possibly involved in pathological disorders were compared with those of aldosterone in the isolated toad skin. The 18-hydroxylated derivatives of deoxycorticosterone and corticosterone, in contrast to their parent compounds, significantly enhanced sodium transport at a concentration of 50 nmol/l. In the presence of glucose, 18-hydroxydeoxycorticosterone increased transepithelial potential difference, as did aldosterone. The 19-nor derivative of deoxycorticosterone, recently implicated in the aetiology of adrenal regeneration hypertension, stimulated sodium transport, unlike 19-nor-corticosterone and 16-oxo-androstenediol. Insulin significantly increased sodium transport in aldosterone-treated skin and lowered the resistance. The natriferic response to vasopressin was potentiated fivefold by exposure of the skin to aldosterone and was doubled in skin exposed to 19-nor-deoxycorticosterone. We conclude that 18-hydroxylated adrenocortical steroids can play a physiological role in salt retention; furthermore, these steroids, as well as 19-nor-deoxycorticosterone, could be involved in pathological conditions such as low renin hypertension. Caution should be exercised in evaluating mineralocorticoid potency solely in terms of the urinary sodium to potassium ratio.
Assuntos
Aldosterona/farmacologia , Corticosterona/farmacologia , Desoxicorticosterona/farmacologia , Pele/metabolismo , Sódio/metabolismo , 18-Hidroxidesoxicorticosterona/farmacologia , Androstenodióis/farmacologia , Animais , Transporte Biológico/efeitos dos fármacos , Bufo marinus , Técnicas de Cultura , Desoxicorticosterona/análogos & derivados , EletrofisiologiaRESUMO
The metabolism of radioactive testosterone, 5alpha-dihydrotestosterone, 4-androstene-3beta,17beta-diol or 4-androstene-3alpha,17beta-diol by the human cell line NHIK 3025, derived from a carcinoma of the uterine cervix, was studied. The cells were grown in Eagle's minimal essential medium (MEM) with a steriod concentration of 10-(7) M for 4 days. Androgen metabolism by this cell line is essentially the same as for other androgen-responsive cells. The most interesting testosterone metabolite in this system is 4-androstene-3beta,17beta-diol, and the separation of this compound from 4-androstene-3alpha,17beta-diol and the two corresponding 5alpha-reduced diols is described. Since 4-androsterone-3beta,17beta-diol is a more potent growth factor for these cells than testosterone, the small conversion of testosterone to 4-androstene-3beta, 17beta-diol observed could be responsible for the growth stimulation by testosterone.
Assuntos
Androstenodióis/metabolismo , Di-Hidrotestosterona/metabolismo , Testosterona/metabolismo , Androstenodióis/farmacologia , Divisão Celular/efeitos dos fármacos , Linhagem Celular , Feminino , Humanos , Testosterona/farmacologia , Útero/metabolismoRESUMO
Since there is convincing evidence for a role of adrenal steroids as precursors of active sex steroids in peripheral tissues, especially prostate cancer, we have studied the effect of the four main adrenal steroids, namely dehydroepiandrosterone sulfate (DHEA-S), DHEA, 5-androstene-3 beta,17 beta-diol (delta 5-diol) and 4-androstene-3,17-dione (delta 4-dione) on the growth of an androgen-sensitive clone (SEM-1) of the mouse mammary carcinoma Shionogi. From a control doubling time of 6.69 +/- 0.03 days, 0.1 microM DHT, 1.0 microM delta 4-dione, 10 microM delta 5-diol, 10 microM DHEA-S and 10 microM DHEA decreased generation time to 1.60 +/- 0.01, 1.69 +/- 0.01, 1.95 +/- 0.01, 4.37 +/- 0.02 and 5.66 +/- 0.03 days, respectively (P less than 0.01 vs. control). The same compounds exerted their stimulatory effects on cell growth at the following ED50 values: 0.06 nM, 16 nM, 90 nM, 150 nM and 16 microM for DHT, delta 4-dione, DHEA, delta 5-diol and DHEA-S, respectively. The stimulatory effect of all compounds was inhibited in a competitive manner by the pure antiandrogen hydroxyflutamide. Further evidence for an action of the adrenal steroids through the androgen receptor is indicated by competition of [3H]testosterone uptake in the tumor cells at the following IC50 values: 0.21 nM, 0.63 nM, 50 nM, 75 nM and 680 nM for DHT, testosterone, delta 4-dione, delta 5-diol and DHEA, respectively. The present data show that the four main adrenal steroids present in the serum of adult men can exert potent stimulatory effects on the growth of an androgen-sensitive cancer cell line through an androgen receptor-mediated mechanism.
Assuntos
Androstenodiol/farmacologia , Androstenodióis/farmacologia , Androstenodiona/farmacologia , Desidroepiandrosterona/análogos & derivados , Desidroepiandrosterona/farmacologia , Crescimento/efeitos dos fármacos , Células Tumorais Cultivadas/efeitos dos fármacos , Androgênios/farmacologia , Animais , Linhagem Celular , Sulfato de Desidroepiandrosterona , Flutamida/farmacologia , Masculino , Neoplasias Mamárias Experimentais/fisiopatologia , CamundongosRESUMO
Treatment of rats with methylandrostenediol (MAD), an anabolic androgen, caused a profound reduction (65%) in the level of cytochrome P-450 11 beta in rat adrenocortical mitochondria as measured by immunoblots using a specific antibody. The decreases in mitochondrial cytochrome P-450scc (15%) and adrenodoxin (20%) were much less than that observed for cytochrome P-45011 beta. A 35% decrease in adrenal microsomal cytochrome P-450 21 and NADPH-cytochrome P-450 reductase levels was brought about by the treatment with MAD. The data establish that the preferential decrease in adrenal steroid 11 beta-hydroxylase activity associated with androgen treatment results from a decrease in cytochrome P-450 11 beta. This is consistent with the role of 11-deoxycorticosterone in the pathogenesis of androgen-induced hypertension in rats.
Assuntos
Córtex Suprarrenal/metabolismo , Adrenodoxina/metabolismo , Androstenodióis/farmacologia , Sistema Enzimático do Citocromo P-450/metabolismo , Isoenzimas/metabolismo , Metandriol/farmacologia , Mitocôndrias/metabolismo , NADPH-Ferri-Hemoproteína Redutase/metabolismo , Córtex Suprarrenal/efeitos dos fármacos , Animais , Feminino , Cinética , Masculino , Mitocôndrias/efeitos dos fármacos , Ratos , Ratos Endogâmicos , Valores de ReferênciaRESUMO
The anti-inflammatory and immunosuppressive functions of corticosteroids have been well established and characterized. In contrast, a different group of native steroids, which include dehydroepiandrosterone (DHEA) and two of its metabolites, androstenediol (5-androstene-3 beta-17 beta-diol, AED) and androstenetriol (5-androstene-3 beta-7 beta-17 beta-triol, beta AET), function in vivo to up-regulate host immune response against infections and counteract stress-induced immunosuppression. Indeed, DHEA and particularly, AED and beta AET, have been shown to protect mice from viral, bacterial, and parasitic infections. In vivo, these three hormones are in opposition to the widely demonstrated immunosuppressive action of glucocorticoids, suggesting a possible new immune regulation mechanism. The individual activity in vitro of each of these steroids, i.e. DHEA, AED, and beta AET, on a mitogen-induced mixed splenocyte proliferation assay were determined. The results showed that DHEA suppressed the proliferation of cultures activated with concanavalin A (ConA) or lipopolysaccharide (LPS) in a dose-dependent manner. AED had little influence on the activation response. However, beta AET potentiated the response to both mitogens significantly above control. The regulation of the cytokine secretion, of both interleukin-2 (IL-2) and interleukin-3 (IL-3), from ConA-activated lymphocytes was affected in the same manner. These functions were depressed by DHEA, unaffected by AED, and potently increased by beta AET. Moreover, the classic immunosuppressive effects of hydrocortisone on ConA-induced lymphocyte proliferation, as well as on IL-2 and IL-3 production, were unaffected by being co-cultured with DHEA and only minimally counteracted by AED at high doses. In contrast, co-culturing with beta AET significantly counteracted the immunosuppressive effects of hydrocortisone on lymphocyte proliferation and cytokine production. These data show that in-vivo, DHEA, AED, and beta AET may have some similar functions, while in vitro, their effects are dramatically different from one another. Only beta AET could markedly potentiate the cellular response by increasing lymphocyte activation and counteracting the immnosuppressive activity of hydrocortisone on lymphocyte proliferation and cytokine production.
Assuntos
Androstenóis/farmacologia , Glucocorticoides/antagonistas & inibidores , Adjuvantes Imunológicos/farmacologia , Androstenodióis/farmacologia , Animais , Concanavalina A/metabolismo , Desidroepiandrosterona/farmacologia , Glucocorticoides/farmacologia , Interleucina-2/biossíntese , Interleucina-3/biossíntese , Lipopolissacarídeos/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , Mitógenos/farmacologia , Baço/citologia , Baço/efeitos dos fármacos , Baço/metabolismo , Timidina/metabolismoRESUMO
The urinary excretion of 3beta,16beta-dihydroxy-5-androsten-17-one (16beta-OH-DHEA) is increased in patients with low renin essential hypertension. This steroid and its isomer 3beta,17beta-dihydroxy-5-androsten-16-one (16-oxo-A) have also been reported to have mineralocorticoid activity in adrenalectomized rats. These findings have led to the postulate that excessive secretion of 16beta-OH-DHEA may be responsible for the production of low renin essential hypertension. In this study unilaterally nephrectomized salt loaded rats injected once a week with 30 mg of 11-desoxycorticosterone acetate per/kg of body weight for 2 month periods developed hypertension. Rats given similar amounts of 16beta-OH-DHEA or 16-oxo-A and rats given no steroids did not develop hypertension. We conclude that it is unlikely that 16beta-OH-DHEA and 16-oxo-A are direct causative factors in the production of low renin essential hypertension.
Assuntos
Androstenodióis/farmacologia , Pressão Sanguínea/efeitos dos fármacos , Desidroepiandrosterona/análogos & derivados , Desoxicorticosterona/farmacologia , Animais , Peso Corporal , Desidroepiandrosterona/farmacologia , Masculino , Ratos , Fatores de TempoRESUMO
On solvolysis of Westphalen-type steroids with a leaving group in the position 6 beta (e.g., 2), products of elimination (followed by rearrangement and fragmentation of the steroid skeleton) were prepared (e.g., 4 and 5). These products were subsequently converted to suitable analogs of the compound, which has been reported to promote hair growth (1). Compounds 11 to 13 exhibited strong antiandrogenic activity in vivo; however, this activity could not be interpreted either in terms of inhibition of 5 alpha-reductase or by strong binding to an androgen receptor.