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1.
Pharmacopsychiatry ; 43(5): 174-8, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20486040

RESUMO

INTRODUCTION: The 5-alpha-reductase inhibitor finasteride is used for the treatment of androgenic alopecia, benign prostate hyperplasia and prostate cancer. Besides inhibiting the conversion of testosterone to the biologically more active 5alpha-dihydrotestosterone, it also inhibits the production of neurosteroids. Decreased neurosteroid levels are postulated to be involved in the pathophysiology of psychiatric disorders such as depression. As neurosteroids metabolized by 5-alpha-reductase influence neural plasticity, we investigated whether finasteride treatment alters adult hippocampal neurogenesis, implicated in the pathophysiology of depression. METHODS: Male C57BL/6N mice were treated subchronically (7 days) with finasteride or vehicle. Adult neurogenesis was assessed at two different time points after treatment (day 1; day 35) using immunohistochemistry. RESULTS: Finasteride treatment led to a significant decrease in brain 5alpha-dihydrotestosterone levels and induced a reversible reduction in the number of newborn cells and young neurons in the hippocampus. 35 days after the last finasteride injection, neurogenesis had returned to normal. DISCUSSION: These data indicate that inhibition of 5-alpha-reductase activity by finasteride treatment influences neuronal plasticity on a structural level. These changes might contribute to the pathophysiology of depressive episodes observed after finasteride treatment.


Assuntos
Inibidores de 5-alfa Redutase , Finasterida/farmacologia , Hipocampo/efeitos dos fármacos , Neurogênese/efeitos dos fármacos , Neurônios/efeitos dos fármacos , 3-Oxo-5-alfa-Esteroide 4-Desidrogenase/metabolismo , Animais , Encéfalo/efeitos dos fármacos , Química Encefálica , Contagem de Células , Di-Hidrotestosterona/análise , Inibidores Enzimáticos/metabolismo , Inibidores Enzimáticos/farmacologia , Finasterida/metabolismo , Hipocampo/citologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Neurônios/citologia , Células-Tronco/citologia , Células-Tronco/efeitos dos fármacos , Testosterona/metabolismo
2.
J Clin Invest ; 83(6): 1903-15, 1989 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-2542376

RESUMO

Because 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) has been shown to play roles in both proliferation and differentiation of novel target cells, the potential expression of 1,25(OH)2D3 receptor (VDR) activity was investigated in cultured bovine aortic endothelial cells (BAEC). Receptor binding assays performed on nuclear extracts of BAEC revealed a single class of specific, high-affinity VDR that displayed a 4.5-fold increase in maximal ligand binding (Nmax) in rapidly proliferating BAEC compared with confluent, density-arrested cells. When confluent BAEC were incubated with activators of protein kinase C (PKC), Nmax increased 2.5-fold within 6-24 h and this upregulation was prevented by sphingosine, an inhibitor of PKC, as well as by actinomycin D or cycloheximide. Immunohistochemical visualization using a specific MAb disclosed nuclear localized VDR in venular and capillary endothelial cells of human skin biopsies, documenting the expression of VDR, in vivo, and validating the BAEC model. Finally, additional experiments indicated that BAEC formed the 1,25(OH)2D3 hormonal metabolite from 25(OH)D3 substrate, in vitro, and growth curves of BAEC maintained in the presence of 10(-8) M 1,25(OH)2D3 showed a 36% decrease in saturation density. These data provide evidence for the presence of a vitamin D microendocrine system in endothelial cells, consisting of the VDR and a 1 alpha-hydroxylase enzyme capable of producing 1,25(OH)2D3. That both components of this system are coordinately regulated, and that BAEC respond to the 1,25(OH)2D3 hormone by modulating growth kinetics, suggests the existence of a vitamin D autocrine loop in endothelium that may play a role in the development and/or functions of this pathophysiologically significant cell population.


Assuntos
Calcifediol/metabolismo , Endotélio Vascular/metabolismo , Epiderme/irrigação sanguínea , Receptores de Esteroides/metabolismo , Animais , Calcifediol/biossíntese , Capilares/metabolismo , Capilares/fisiologia , Bovinos , Divisão Celular , Células Cultivadas , Endotélio Vascular/análise , Endotélio Vascular/fisiologia , Ativação Enzimática , Epiderme/análise , Epiderme/metabolismo , Humanos , Imuno-Histoquímica , Biossíntese de Proteínas , Proteína Quinase C/metabolismo , Receptores de Calcitriol , Receptores de Esteroides/análise , Receptores de Esteroides/fisiologia , Transcrição Gênica
3.
Gen Physiol Biophys ; 26(1): 40-7, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17579253

RESUMO

Lockhart equation was derived for explaining plant cell expansion where both cell wall extension and water uptake must occur concomitantly. Its fundamental contribution was to express turgor pressure explicitly in terms of osmosis and wall mechanics. Here we present a new equation in which pressure is determined by temperature. It also accounts for the role of osmosis and consequently the role of water uptake in growing cell. By adopting literature data, we also attempt to report theoretically the close relation between plant elongation and cell wall extensibility. This is accomplished by the modified equation of growth solved for various temperatures in case of two different species. The results enable to interpret empirical data in terms of our model and fully confirm its applicability to the investigation of the problem of plant cell extensibility in function of environmental temperature. Moreover, by separating elastic effects from growth process we specified the characteristic temperature common for both processes which corresponds to the resonance energy of biochemical reactions as well as to the rapid softening of the elastic modes toward the high temperature end where we encountered viscoelastic and/or plastic behavior as dominating. By introducing analytical formulae connected with growth and elastic properties of the cell wall, we conclude with the statement how these both processes contribute quantitatively to the resonance-like shape of the elongation curve. In addition, the tension versus temperature "phase diagram" for a living plant cell is presented.


Assuntos
Parede Celular/fisiologia , Desenvolvimento Vegetal , Fenômenos Fisiológicos Vegetais , Tecido Elástico/fisiologia , Modelos Biológicos , Oryza/citologia , Oryza/crescimento & desenvolvimento , Osmose , Células Vegetais , Temperatura , Fatores de Tempo
4.
Gen Physiol Biophys ; 25(2): 125-36, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16917127

RESUMO

In this article we deal with the definition of a new phenomenological model with physical bases for the response of short-term cell expansion growth to temperature. Although the interest on both the biomechanical bases of elongation growth and on temperature responses has a long lasting development in plant biology and biophysics, yet the question of the mode of actions of temperature is a very relevant and still open one. The purpose of our paper was not to deal with all the complexity of the possible effects of temperature on a growing cell but to concentrate on two more focused questions: i) whether it is possible to specify an optimal temperature for growth responses all along development by defining some phenomenological equations for temperature response, ii) can we learn something from that on the temperature dependence of the cell wall expansion process using a minimal analytical modelling? To answer both questions we introduce (by extending Lockhart approach) the notion of temperature by simple thermodynamical reasoning. Assuming incompressibility of water (by the constant molar density n/V ) we also accounted for the role of osmosis and consequently - the role of water uptake in growing cell. This approach allowed us (by comparing theoretical solutions and experimental results) not only to determine the specific (resonance) temperature (or corresponding absorption energy kBT*) of the optimal growth but also draw conclusions about the cell wall extensibility dependence on temperature and its evolution in time. A straightforward application of our method to determine optimum growth temperature for different plant species in a greenhouse practice (as its simple implication) can also be recommended.


Assuntos
Fenômenos Fisiológicos Vegetais , Plantas/metabolismo , Zea mays/fisiologia , Fenômenos Biomecânicos/métodos , Parede Celular/metabolismo , Modelos Biológicos , Modelos Estatísticos , Osmose , Desenvolvimento Vegetal , Temperatura , Fatores de Tempo
5.
Cancer Res ; 49(8 Suppl): 2220s-2221s, 1989 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-2539257

RESUMO

A 29-year-old woman with moderately elevated blood pressure and signs of hyperandrogenism (hirsutism and acne) but without typical Cushing's syndrome symptoms has been followed for almost 6 years. Steroid and glucocorticoid receptor studies indicated a primary glucocorticoid receptor defect. Elevated androgen values were of special interest. Clinical manifestation of hyperandrogenism seemed not to be proportional to the biochemical findings. Therefore, the possibility of a partial androgen receptor defect should also be considered.


Assuntos
Receptores de Glucocorticoides/fisiologia , Acne Vulgar/etiologia , Hormônio Adrenocorticotrópico/sangue , Adulto , Androgênios/metabolismo , Feminino , Hirsutismo/etiologia , Humanos , Hipertensão/etiologia , Receptores Androgênicos/fisiologia
6.
J Clin Endocrinol Metab ; 74(5): 1195-7, 1992 May.
Artigo em Inglês | MEDLINE | ID: mdl-1569167

RESUMO

19-Noraldosterone, which was recently shown to be synthesized and produced in the human adrenal gland, possesses potent mineralocorticoid activity. 18,19-Dihydroxycorticosterone [18,19-(OH)2B], a possible precursor of 19-noraldosterone, has also been identified in human urine. To elucidate the regulatory mechanism for these newly described steroids, we studied the effect of sodium restriction on the urinary excretion of 19-noraldosterone and 18,19-(OH)2B in six normal subjects. 18,19-(OH)2B and 19-noraldosterone were measured by specific RIAs after purification of the urine extract by high performance liquid chromatography. The 24-h urinary excretion of 19-noraldosterone and 18,19-(OH)2B during the control period were 107 +/- 40 (+/- SE) pmol/day and 5.6 +/- 0.8 nmol/day, respectively. After sodium restriction, the values increased approximately 2-fold (P less than 0.05), to 259 +/- 76 pmol/day and 15.6 +/- 4.5 nmol/day, respectively. Virtually identical responses were seen for aldosterone (from 21 +/- 6.0 to 38 +/- 10 nmol/day), 18-hydroxycorticosterone (from 9.9 +/- 1.1 to 21 +/- 2.8 nmol/day), and 18-hydroxycortisol (from 377 +/- 93 to 554 +/- 129 nmol/day). These observations suggest that 19-noraldosterone and 18,19-(OH)2B are partly under the control of the renin-angiotensin system in normal subjects.


Assuntos
18-Hidroxicorticosterona/análogos & derivados , Aldosterona/análogos & derivados , Dieta Hipossódica , Mineralocorticoides/urina , 18-Hidroxicorticosterona/urina , Adulto , Aldosterona/sangue , Aldosterona/urina , Humanos , Masculino , Pessoa de Meia-Idade , Renina/sangue
7.
J Clin Endocrinol Metab ; 85(3): 1133-6, 2000 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10720051

RESUMO

The enzyme 11-beta-hydroxysteroid dehydrogenase (11-beta-HSD) regulates glucocorticoid activity by converting cortisol into cortisone and vice versa. Frequent signs of major depression are elevated concentrations of circulating cortisol and ACTH. However, no information is available about the activity of 11-beta-HSD in this disorder. Therefore, we compared diurnal plasma concentrations of cortisol and cortisone and their ratios, reflecting 11-beta-HSD activity, in 25 severely depressed patients (Hamilton Depression Scale, 29 +/- 6; 14 men, 11 women, age 22-77 yr; mean, 47 +/- 16) and 30 control persons (20 men, 10 women age 23-85 yr; mean, 51 +/- 19). Cortisol and cortisone were measured at 0900 h, 1100 h, 1300 h, 2000 h, 2200 h, 0100 h, 0300 h, and 0700 h with specific RIAs after extraction. Both cortisol and cortisone concentrations were significantly increased in patients compared with controls (cortisol, 251.7 +/- 113.1 vs. 160 +/- 96.6 nmol/L; cortisone, 32.8 +/- 10.9 vs. 21.9 +/- 10.9 nmol/L). The calculated ratios of cortisol to cortisone were similar in controls and patients. Similar to cortisol, the circadian variation of cortisone was flattened in patients with the ratio of maximal cortisone to minimal cortisone being 1.9-fold higher in controls than in patients. There was no gender-specific difference in cortisone values neither in patients nor in controls. We conclude that in major depression increased cortisol is not due, at least partly, to an altered 11-beta-HSD activity or to a decrease in cortisone.


Assuntos
Ritmo Circadiano/fisiologia , Cortisona/sangue , Transtorno Depressivo/sangue , 11-beta-Hidroxiesteroide Desidrogenases , Corticosterona/metabolismo , Transtorno Depressivo/psicologia , Feminino , Humanos , Hidrocortisona/sangue , Hidroxiesteroide Desidrogenases/sangue , Masculino , Pessoa de Meia-Idade , Escalas de Graduação Psiquiátrica
8.
J Clin Endocrinol Metab ; 64(4): 771-7, 1987 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-3493258

RESUMO

21-Deoxyaldosterone appears in urine in free and conjugated forms. Total excretion is best determined after acid hydrolysis (pH 1) of urine, followed by extraction, repeated chromatographic purification, and quantitation of the steroid by RIA. 21-Deoxyaldosterone excretion was normal in 70% of patients with essential hypertension (n = 18), while 30% (n = 8) had more or less elevated values. In patients with primary aldosteronism (n = 21) elevated as well as normal values of urinary 21-deoxyaldosterone were found, indicating that in some patients aldosterone may be formed not only from corticosterone but also from the 21-deoxy compound. In patients with 21-hydroxylase deficiency (n = 21) urinary 21-deoxyaldosterone was invariably elevated, whether the patients had the virilizing or salt-losing form of the disease. Although the clinical manifestations of the salt-losing form seem unrelated to the inability to convert 21-deoxyaldosterone to aldosterone, the determination of 21-deoxyaldosterone adds insight into the biosynthesis of aldosterone in primary aldosteronism and 21-hydroxylase deficiency.


Assuntos
Hiperplasia Suprarrenal Congênita , Aldosterona/análogos & derivados , Hiperaldosteronismo/urina , Esteroide Hidroxilases/deficiência , Adolescente , Adulto , Aldosterona/urina , Cromatografia Líquida de Alta Pressão , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Radioimunoensaio
9.
J Clin Endocrinol Metab ; 80(3): 737-44, 1995 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-7883826

RESUMO

Ten cases of adrenal adenomas, one case with unilateral adrenal hyperplasia, and another case with apparent bilateral are reported, in whom an alternative pathway of aldosterone via 21-deoxyaldosterone is operative. They all manifested hypertension, low renin activity, low normal potassium values, as well as high urinary excretion rates of 21-deoxyaldosterone and its related metabolite Kelly's-M1 steroid. In all cases, urinary aldosterone metabolites (aldosterone-18-glucuronide and tetrahydroaldosterone) and aldosterone precursor 18-hydroxycorticosterone levels were normal. Hence, the adrenal lesions give rise to hyper-21-deoxyaldosteronism. 21-Deoxyaldosterone is a weak mineralocorticoid, and its elevated production in the presence of normal aldosterone can induce a pathological state of hypermineralocorticoidism. Adrenalectomy resulted in normalization of hypertension in six of eight and amelioration in two of eight cases. Six of seven adenoma cases examined as well as the case of unilateral adrenal hyperplasia were sensitive to ACTH. One of the seven adenomas and, as expected, the case with apparent bilateral hyperplasia were angiotensin responsive. Histologically and electron microscopically, the operated adenomas consisted predominantly of clear cells, characterized by mitochondria with tubulo-vesicular internal structure similar to those of the zona fasciculata (in contrast, our classical Conn's adenoma with normal 21-deoxyaldosterone excretion exhibited a more heterogenous histological appearance and were, in terms of ultrastructure, more similar to cells of the zona glomerulosa). Ultrastructurally and immunocytochemically, the clear cells of 21-deoxyaldosterone adenomas showed features of both the zona glomerulosa and the zona fasciculata and are, hence, considered to be hybrid cells. We conclude that the determination of 21-deoxyaldosterone and Kelly's-M1 should be considered in the diagnosis of mineralocorticoid-induced forms of hypertension, especially when an adrenal adenoma has been detected with an imaging procedure.


Assuntos
Adenoma/metabolismo , Neoplasias das Glândulas Suprarrenais/metabolismo , Aldosterona/análogos & derivados , Hipertensão/etiologia , Pregnanos/metabolismo , Adenoma/patologia , Neoplasias das Glândulas Suprarrenais/patologia , Adulto , Aldosterona/análise , Aldosterona/metabolismo , Feminino , Humanos , Hipertensão/diagnóstico , Hipertensão/metabolismo , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade
10.
Psychoneuroendocrinology ; 25(8): 765-71, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-10996472

RESUMO

Hyperactivity of the HPA-system in major depression is reflected by an increased secretion of adrenal hormones especially cortisol and dehydroepiandrosterone (DHEA). In women for whom androgenicity is associated with cardiovascular disorders the dominant source of androstenedione and testosterone secretion are the adrenal glands. To date, there is only sparse information about the regulation of androstenedione, testosterone and dihydrotestosterone (DHT) concentrations in women with severe major depression.Therefore, 11 pre- and postmenopausal, severely depressed, hypercortisolemic women (Hamilton Depression Scale, 31.3+/-5.9; age, 28-77 yrs; mean, 48. 1+/-18.1 yrs) and 11 age-matched healthy female controls (age, 24-81 yrs; mean, 47.9+/-21.5 yrs) underwent a 24 hour (h) blood sampling starting at 0800 h with 30-minute sampling intervals. By applying multivariate analysis of covariance with age as covariate, androstenedione, testosterone and DHT plasma levels at 0900 h show a trend for elevated concentrations in depressed women compared to controls (F(1,19)=2.7; P=0.057). Univariate F tests reveal a significant difference between the groups for androstenedione (4. 19+/-1.571 vs 2.584+/-1.257 nmol/l; P<0.05) testosterone (1.110+/-0. 278 vs 0.833+/-0.347 nmol/l; P<0.05) and DHT (0.656+/-0.207 vs 0. 483+/-0.242 nmol/l; P<0.05). Mean ACTH (16.4+/-10.4 vs 10.4+/-2.4 pmol/l; P=0.89), LH (13.5+/-11.8 vs 8.9+/-9.2 IU/l; P=0.12), FSH (35. 2+/-33.1 vs 31.3+/-35.7 IU/l; P=0.67) and estradiol (135.4+/-157.4 vs 82.2+/-85.1 pmol/l; P=0.20) plasma levels did not differ between patients and controls. Further, there was a trend towards an age related decline in testosterone secretion in healthy controls (r=-0. 24; P=0.08) which did not occur in depressed patients (r=0.17; P=0. 96), while the calculated ratio of DHEA to testosterone was similar in both groups (0.2+/-0.14 vs 0.13+/-0.7; P=0.21, unpaired t-test). In conclusion, androstenedione, testosterone and DHT concentrations all were increased in hypercortisolemic women with severe major depression. These findings are best explained as a consequence of an overstimulation of the adrenal glands through pituitary and hypothalamic sites of the HPA-system.


Assuntos
Androstenodiona/sangue , Depressão/sangue , Di-Hidrotestosterona/sangue , Testosterona/sangue , Hormônio Adrenocorticotrópico/sangue , Adulto , Idoso , Estradiol/sangue , Feminino , Hormônio Foliculoestimulante/sangue , Humanos , Hidrocortisona/sangue , Hormônio Luteinizante/sangue , Pessoa de Meia-Idade , Análise Multivariada , Pós-Menopausa , Pré-Menopausa
11.
J Steroid Biochem Mol Biol ; 45(1-3): 65-8, 1993 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-8386933

RESUMO

Pregnancy-induced hypertension (PIH) is a frequent cause of maternal and neonatal morbidity and mortality. In the present study we focused on the pathophysiology of PIH, mainly on the role of mineralocorticoids, reversed blood pressure patterns, and the resulting necessity of continuous monitoring of the preeclamptic mother. Problems of antihypertensive therapy are discussed and the first results of a pilot study with Urapidil are presented. To examine the role of mineralocorticoids in the pathophysiology of PIH, we studied plasma aldosterone and 18-hydroxy-corticosterone (18-OH-B) levels in 25 women with PIH and in 25 healthy pregnant women. Furthermore, we evaluated the mineralocorticoid receptor (MR) count in mononuclear leukocytes in the 2 groups. The MR-count was significantly decreased in the PIH-group. The values of plasma aldosterone and 18-OH-B were also low. These results cannot be explained by receptor down-regulation due to higher level of mineralocorticoids of the zona glomerulosa. Perhaps deoxycorticosterone or a hitherto unknown mineralocorticoid is responsible for the hypertension and altered MR-status. The first results of continuous blood pressure measurements with a noninvasive, real-time blood pressure monitor (Finapres) are presented. The comparison of the obtained values with intraarterial measurements demonstrates a good correlation between the two methods. We also report on the first experiences with Urapidil in the treatment of hypertension in severe preeclampsia. The data show that hypertension in preeclamptic women can be treated by Urapidil without side effects or reflex-tachycardia. Further studies will have to prove if Urapidil is suited for prepartal treatment of PIH as well.


Assuntos
Hipertensão/fisiopatologia , Pré-Eclâmpsia/fisiopatologia , Complicações Cardiovasculares na Gravidez/fisiopatologia , Anti-Hipertensivos/administração & dosagem , Anti-Hipertensivos/uso terapêutico , Determinação da Pressão Arterial/métodos , Feminino , Humanos , Hipertensão/tratamento farmacológico , Hipertensão/metabolismo , Leucócitos Mononucleares/metabolismo , Mineralocorticoides/metabolismo , Projetos Piloto , Piperazinas/administração & dosagem , Piperazinas/uso terapêutico , Pré-Eclâmpsia/metabolismo , Gravidez , Complicações Cardiovasculares na Gravidez/metabolismo , Receptores de Mineralocorticoides , Receptores de Esteroides/metabolismo
12.
J Steroid Biochem Mol Biol ; 37(2): 261-7, 1990 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-2268558

RESUMO

Several new 4,19-substituted steroids and previously synthesized corticosteroids were assayed for affinity to type 1 receptors in human mononuclear leukocytes. 11 beta,19-epoxy-4,21-dihydroxypregn-4-ene-3,20-dione (2) was hydrogenated with Pd-C to yield a mixture of all four dihydro derivatives 5, accompanied by 4,21-diacetoxy-11 beta,19-epoxy-3-hydroxypregnan-20-one (6) and 21-acetoxy-11 beta,19-epoxy-4-hydroxypregnane-3,20-dione (7). With hot acetic + p-toluenesulfonic acid 5 underwent rearrangement to 21-acetoxy-11 beta,19-epoxypregn-5-ene-4,20-dione (8) Pd-C hydrogenation of 3,21-diacetoxy-5 beta,19-cyclopregna-2,9(11)-diene-4,20-dione (10) gave 3,21-diacetoxy-5 beta,19-cyclopregn-5-ene-4,20-dione (11) and the 9,11-dihydro derivative of the latter. Treatment of 10 with warm HCl furnished 19-chloro-4,21-dihydroxypregna-4,9(11)-diene-3,20-dione (13). Pd-C hydrogenation of its diacetate 14 afforded the 4,5-dihydro derivative 18, 19-chloro-21-acetoxypregn-9(11)-en-20-one (15), its 4-acetoxy derivative 16 and the 3,4-diacetoxy derivative 17. When tested in a radioreceptor assay in human mononuclear leukocytes the synthesized compounds showed only low relative binding affinities (RBA) to type 1 receptor, the highest being 0.72% for 13 (aldosterone = 100%). For comparison, other RBA in this system were: 19-noraldosterone, 20%; 18-deoxyaldosterone, 5.8%; 18-deoxy-19-noraldosterone, 4.7%; 18,21-anhydroaldosterone, 0.37%; 17-isoaldosterone, 7.6% and apoaldosterone, 4.3%


Assuntos
Desoxicorticosterona/análogos & derivados , Desoxicorticosterona/síntese química , Leucócitos Mononucleares/metabolismo , Receptores de Glucocorticoides/metabolismo , Aldosterona/sangue , Ligação Competitiva , Desoxicorticosterona/química , Desoxicorticosterona/farmacologia , Humanos , Indicadores e Reagentes , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Estrutura Molecular , Ensaio Radioligante , Receptores de Glucocorticoides/efeitos dos fármacos , Relação Estrutura-Atividade , Trítio
13.
J Steroid Biochem Mol Biol ; 37(4): 599-604, 1990 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-2278845

RESUMO

The recently synthesized 18-C-steroid derivative, 19-nor-aldosterone(19-nor- aldo) and 18-hydroxy-19-nor-corticosterone(18-OH-19-nor-corticosterone) possess mineralocoroticoid and hypertensinogenic activity. They and an additional newly synthesized steriod, 18,19-dihydroxycorticosterone[18,19(OH)2-corticosterone], may play a role in the etiology and pathogenesis of disorders thought to be caused by steroids with mineralocorticoid and hypertensionogenic properties. In this study we provide evidence that 19-nor-aldo, 18-OH-19-nor-corticosterone and 18,19(OH)2-corticosterone are produced in vitro by aldosterone-producing adrenal adenomas and adenomas and adenoma of Cushing's syndrome. "silent" adrenal adenomas and the adjacent adrenal tissue. Measurable amounts of these steroids were found in the incubation fluids of adrenal tissues using specific RIAs performed after a sequence of HPLC systems. The rates of production of the three steroids were high in the aldosterone-producing adrenal adenomas and in adrenal hyperplasia compared with in either Cushing's adenoma or "silent" adenoma.


Assuntos
18-Hidroxicorticosterona/análogos & derivados , Adenoma/metabolismo , Neoplasias das Glândulas Suprarrenais/metabolismo , Aldosterona/análogos & derivados , Aldosterona/biossíntese , Cromatografia Líquida de Alta Pressão , Síndrome de Cushing/metabolismo , Humanos , Radioimunoensaio
14.
J Steroid Biochem Mol Biol ; 50(5-6): 319-27, 1994 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-7918119

RESUMO

21-Deoxyaldosterone has been postulated to be a precursor of aldosterone in an alternative biosynthesis pathway and Kelly's-M1 is considered to be its metabolite. In healthy volunteers, the excretion rate of 21-deoxyaldosterone and of Kelly's-M1 are significantly lower than the aldosterone metabolites, aldosterone-18-glucuronide and tetrahydro-aldosterone and than the aldosterone precursor 18-OH-corticosterone. Essential hypertension patients (with low and normal renin) excrete comparable values of 21-deoxyaldosterone and Kelly's-M1 as normotensives. In 66% of aldosterone-producing adenoma cases (APA) and in 60% of idiopathic hyperaldosteronism (IHA) patients, significantly raised values of 21-deoxyaldosterone and Kelly's-M1 were found. The patients with the high excretion rates of both steroids showed only moderately increased values of the aldosterone metabolites, aldosterone-18-glucuronide and tetrahydro-aldosterone, as well as of the aldosterone precursor 18-OH-corticosterone. In contrast, the latter mentioned steroids were excreted in higher amounts in those patients with normal excretion of 21-deoxyaldosterone and Kelly's-M1. Hence, it is suggested that aldosterone is produced alternatively either via 18-OH-corticosterone alone or additionally via 21-deoxyaldosterone. Furthermore, in three cases of "incidentally" discovered adrenal adenomas, 21-deoxyaldosterone and Kelly's-M1 were the only elevated steroids. After adrenalectomy, excretion of 21-deoxyaldosterone and of Kelly's-M1 and blood pressure returned to normal, which proves that these steroids play a role in blood pressure regulation. In essential hypertension, ACTH infusion induced a significant increase of 21-deoxyaldosterone and Kelly's-M1. However, the increase after angiotensin II was 3- to 6-fold higher than after ACTH. IHA patients proved to be more responsive to angiotensin II; and, in contrast, APA cases proved to be more sensitive to ACTH. The data suggest that beside the main route of aldosterone biosynthesis via 11-deoxycorticosterone, corticosterone and 18-OH-corticosterone an alternative pathway exists via 21-deoxyaldosterone in healthy and in hypertensive patients. There are similarities between the regulation of 21-deoxyaldosterone and the regulation of aldosterone. The determination of 21-deoxyaldosterone and its possible metabolite Kelly's-M1 might be appropriate in the diagnosis of mineralocorticoid-induced forms of hypertension, especially when an adrenal adenoma is discovered.


Assuntos
Aldosterona/análogos & derivados , Hiperaldosteronismo/metabolismo , Hipertensão/metabolismo , Pregnanos/urina , Adenoma/metabolismo , Hormônio Adrenocorticotrópico/farmacologia , Adulto , Aldosterona/urina , Angiotensina II/farmacologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
15.
Steroids ; 63(7-8): 401-5, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9654646

RESUMO

The adrenal gland is involved in the control of urinary sodium excretion mainly via the secretion of the mineralocorticoid aldosterone. Although under certain conditions glucocorticoid seem to be also involved in the regulation of sodium homeostasis, there are contradictory reports on the relationship between cortisol secretion and sodium intake. Given recent findings linking regulation of physiological activity of steroids to the activity of specific enzymatic pathways, we have examined changes in urinary excretion of cortisol and its metabolites in eight healthy volunteers on a low sodium diet. Urinary steroids were measured with specific radioimmunoassays after extraction and chromatography (F and E) or after dilution (THF and THE). Excretion of cortisol (124 +/-41 nmol/day) was significantly lower on Day 2 (86 +/- 27 nmol/day, p < 0.01) and Day 7 (85 +/- 25 nmol/day, p < 0.01) of sodium restriction. On the same samples calculated ratios of THF/F (55 +/- 15; 61 +/- 22; 68 +/- 21) and E/F (2.5 +/- 0.6; 2.8 +/- 1.4; 3.0 +/- 1.3) reflecting the activity of 5 beta-reductase and 11 beta-hydroxysteroid dehydrogenase, respectively, showed significant increases in the former on both Days 2 and 7 and for the latter only on Day 7. This study supports the notion that sodium restriction decreases urinary cortisol excretion and provides evidence that increased activity of 5 beta-reductase and lowered metabolism by 11 beta-HSD are presumably the mechanisms of this decrease.


Assuntos
Dieta Hipossódica , Hidrocortisona/urina , Cloreto de Sódio na Dieta/farmacocinética , Adulto , Biotransformação , Humanos , Hidrocortisona/metabolismo , Rim/metabolismo , Fígado/metabolismo , Masculino , Potássio/urina , Cloreto de Sódio na Dieta/urina
16.
Steroids ; 54(1): 11-9, 1989 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-2640565

RESUMO

18,21-Anhydroaldosterone 8, 18,21-anhydro-19-noraldosterone 9, and 3 alpha, 5 beta-tetrahydro-18,21-anhydro-19-noraldosterone 13, which may be present in acid-processed urine, were prepared by cleaving their 20-ketal derivatives 2, 3, and 12 with hot mineral acid. Compounds 8 and 9 were also made by direct dehydration of aldosterone 5 and 19-noraldosterone 10 in good yield. The reverse ring opening of 8 to 5 could be carried out in moderate yield with an acetic acid-acetic anhydride-perchloric acid mixture, while an analogous ring opening of 9 gave only a poor yield of 10.


Assuntos
Aldosterona/análogos & derivados , Fenômenos Químicos , Química , Espectrofotometria Infravermelho
17.
Steroids ; 56(11): 566-70, 1991 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-1814024

RESUMO

18,19-Dihydroxycorticosterone (18,19(OH)2-B) and 18-hydroxy-19-norcorticosterone (18-OH-19-nor-B) measurements were carried out on the urine of patients with primary aldosteronism (PA), essential hypertension (EHT), and liver cirrhosis with (LC, SA (+)) and without (LC, SA (-)) aldosteronism. The separation of these steroids was performed by extraction and high-performance liquid chromatography followed by radioimmunoassay (RIA) with specific antibodies prepared in our laboratory. 18,19(OH)2-B excretion was elevated in patients with PA (24 +/- 5.9 [+/- SE] micrograms/24 hr; n = 15) and LC, SA (+) (83 +/- 9.4 micrograms/24 hr; n = 8). Values in LC, SA (-) (3.1 +/- 1.2 micrograms/24 hr; n = 8) and in EHT (3.7 +/- 0.4 micrograms/24 hr; n = 42) were found to be similar to those in normal subjects (5.5 +/- 0.9 micrograms/24 hr; n = 30). The values of urinary 18-OH-19-nor-B in PA and LC, SA (+) were higher than in LC, SA (-) EHT and normal subjects (P less than 0.05). Values in the latter three groups, as compared with each other, did not show significant alterations. Nothing is known about the biologic relevance of 18,19(OH)2-B and very little about that of 18-OH-19-nor-B, but the latter steroid seems to potentiate experimental renal hypertension. One can speculate about possible roles of both steroids as precursors of other steroids, e.g., the biologically potent mineralocorticoid 19-noraldosterone. The data obtained suggest that it is not relevant to measure the urinary levels of either steroid in these clinical syndromes.


Assuntos
18-Hidroxicorticosterona/análogos & derivados , Hiperaldosteronismo/urina , Hipertensão/urina , 18-Hidroxicorticosterona/urina , Adulto , Idoso , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Hiperaldosteronismo/complicações , Hipertensão/complicações , Cirrose Hepática/urina , Pessoa de Meia-Idade
18.
Exp Clin Endocrinol Diabetes ; 112(1): 59-61, 2004 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-14758573

RESUMO

Preclinical research suggests adrenal beta-adrenergic receptors to be involved in the regulation of steroid synthesis. In a group of healthy male volunteers, we compared ACTH-induced cortisol and dehydroepiandrosterone (DHEA) secretion after pre-treatment with orciprenaline, propranolol or placebo. Neither baseline nor ACTH-induced steroid secretion differed between these conditions. Our data do not support the hypothesis that the adrenal beta-receptor plays a major role in steroid secretion in humans.


Assuntos
Agonistas Adrenérgicos beta/farmacologia , Antagonistas Adrenérgicos beta/farmacologia , Hormônio Adrenocorticotrópico/fisiologia , Hidrocortisona/metabolismo , Metaproterenol/farmacologia , Propranolol/farmacologia , Receptores Adrenérgicos beta/metabolismo , Hormônio Adrenocorticotrópico/metabolismo , Adulto , Cosintropina/metabolismo , Desidroepiandrosterona/sangue , Desidroepiandrosterona/metabolismo , Humanos , Hidrocortisona/sangue , Masculino , Sistema Hipófise-Suprarrenal/metabolismo , Taxa Secretória/efeitos dos fármacos
19.
Ann Endocrinol (Paris) ; 51(1): 1-15, 1990.
Artigo em Francês | MEDLINE | ID: mdl-2221818

RESUMO

The authors review some current ideas concerning the role of 18-hydroxylated corticosteroids as mineralocorticoids themselves and as possible precursors of the principal mineralocorticoid, aldosterone. In particular, the physiological and pharmacological agents affecting their secretion are discussed together with a description of the methods used for their analysis in plasma in the department of Clinical Biochemistry Pitié-Salpétrière. Finally, the value of these assays in the differential diagnosis of mineralocorticoid hypertension and inborn errors of corticosteroid biosynthesis is assessed and the constraints on sampling technique listed.


Assuntos
18-Hidroxicorticosterona/sangue , 18-Hidroxidesoxicorticosterona/sangue , Doenças das Glândulas Suprarrenais/sangue , 18-Hidroxicorticosterona/metabolismo , 18-Hidroxidesoxicorticosterona/metabolismo , Aldosterona/metabolismo , Desoxicorticosterona/metabolismo , Humanos
20.
Z Kinder Jugendpsychiatr Psychother ; 31(1): 7-15, 2003 Feb.
Artigo em Alemão | MEDLINE | ID: mdl-12616745

RESUMO

OBJECTIVE: While an association between androgens and different types of aggression has been well documented in male offenders, the influence of androgens on externalizing behavior in adolescents at risk for antisocial behavior has not been investigated so far. METHODS: Plasma levels of the main androgen metabolites testosterone (T) and 5a-dihydrotestosterone (DHT) were measured in N = 119 14-year-olds (51 boys, 68 girls) from a prospective longitudinal study of children at risk. The Achenbach Child Behavior Checklist (CBCL) and the Youth Self Report Form (YSR) were used to assess externalizing behavior at age 14. RESULTS: The CBCL revealed significant positive correlations between DHT levels and the subscales "externalizing problems" and the problem scales "aggressive behavior" and "delinquent behavior" in male adolescents. Only the YSR subscale "delinquent behavior" exhibited a marginally significant association with DHT. Neither scale showed any significant correlations between androgen levels and externalizing behavior in female adolescents. CONCLUSIONS: Earlier findings of androgen effects on aggressive and antisocial behavior in male offenders were confirmed for male adolescents from a general population sample. The results stress the importance of the androgen metabolite DHT.


Assuntos
Agressão/fisiologia , Transtorno da Personalidade Antissocial/fisiopatologia , Di-Hidrotestosterona/sangue , Controle Interno-Externo , Testosterona/sangue , Adolescente , Agressão/psicologia , Transtorno da Personalidade Antissocial/diagnóstico , Transtorno da Personalidade Antissocial/psicologia , Feminino , Humanos , Estudos Longitudinais , Masculino , Determinação da Personalidade , Estudos Prospectivos , Fatores Sexuais
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