57 research outputs found

    Plasma 11-deoxycorticosterone (DOC) and mineralocorticoid receptor testicular expression during rainbow trout Oncorhynchus mykiss spermiation: implication with 17alpha, 20beta-dihydroxyprogesterone on the milt fluidity?

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    Background: In rainbow trout (Oncorhynchus mykiss), the endocrine control of spermiation is not fully understood. Besides IIketotestosterone (IIKT) and 17alpha, 20beta-dihydroxyprogesterone (MIS), the potential physiological ligand of the mineralocorticoid receptor (MR) II-deoxycorticosterone (DOC), is a credible candidate in O. mykiss spermiation regulation as spermiation is accompanied with changes in aqueous and ionic flows. Methods: In this study, we investigated potential roles of DOC during spermiation 1) by describing changes in blood plasma DOC level, MR mRNA abundance during the reproductive cycle and MR localization in the reproductive tract 2) by investigating and comparing the effects of DOC (10 mg/kg) and MIS (5 mg/kg) supplementations on sperm parameters 3) by measuring the in vitro effect of DOC on testis MIS production. Results: The plasma concentration of DOC increased rapidly at the end of the reproductive cycle to reach levels that were 10-50 fold higher in mature males than in immature fish. MR mRNA relative abundance was lower in maturing testes when compared to immature testes, but increased rapidly during the spermiation period, immediately after the plasma rise in DOC. At this stage, immunohistochemistry localized MR protein to cells situated at the periphery of the seminiferous tubules and in the efferent ducts. Neither DOC nor MIS had significant effects on the mean sperm volume, although MIS treatment significantly increased the percentage of males producing milt. However, a significant reduction in the spermatocrit was observed when DOC and MIS were administrated together. Finally, we detected an inhibitory effect of DOC on testis MIS production in vitro. Conclusion: These results are in agreement with potential roles of DOC and MR during spermiation and support the hypothesis that DOC and MIS mechanisms of action are linked during this reproductive stage, maybe controlling milt fluidity. They also confirm that in O. mykiss MIS is involved in spermiation induction

    Development of a radioimmunoassay for serum 21-deoxycortisol and its potential application in the diagnosis of congenital adrenal hyperplasia

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    Serum 21-deoxycortisol (21DF) has been considered a useful hormonal marker for the diagnosis of congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency (21OHD). Although several radioimmunoassay (RIA) methods for 21DF have been reported, none are commercially available. We developed a RIA adapted for 21DF determination, preceded by ether-extraction and liquid chromatographic separation (HPLC) of samples. The assay was employed to evaluate children (15F/10M) with the classic form of 21OHD and a control group (5F/8M). The antibody obtained, in addition to efficient HPLC separation, permitted tritiated cortisol instead of 21DF to be used, since labeled ³H-21DF is expensive and difficult to obtain. Serum cortisol levels were reduced in patients with 21OHD (48h following therapy withdrawal) as compared to controls (2.1±2.1 vs. 16.2±7.0mug/dl), whereas serum levels of 21DF were significantly elevated (1,359±853ng/dl, ranging from 434 to 3,079) in the former, but consistently below the sensitivity limit of the assay (156ng/dl) in the latter group. The reported method, although devoid of sensitivity for its application in normal subjects, permits 21DF to be quantified in patients with 21OHD, with adequate sensitivity and specificity to diagnose and follow patients with this condition.O 21-deoxicortisol (21DF) sérico tem sido considerado um excelente marcador para o diagnóstico da hiperplasia adrenal congênita (HAC) por deficiência de 21-hidroxilase (D21OH). Embora vários métodos de radioimunoensaio (RIE) tenham sido descritos para 21DF, nenhum deles está disponível comercialmente. Desenvolvemos um RIE adaptado para a dosagem de 21DF, com extração prévia das amostras com éter e separação por cromatografia líquida (HPLC). O ensaio foi aplicado para a avaliação de crianças portadoras da forma clássica de D21OH (15F/10M) e um grupo controle (5F/8M). O anticorpo obtido, associado à eficiência da separação por HPLC, viabilizou o emprego do cortisol triciado neste RIE. Enquanto nos pacientes os níveis de cortisol estavam reduzidos (48h após suspensão do tratamento) em comparação com o grupo controle (2,1±2,1 vs. 16,2±7,0mig/dl), os valores do 21DF sérico estavam bastante elevados (1.359±853ng/dl, variando de 434 a 3.079), embora consistentemente abaixo do limite de sensibilidade (156ng/dl) no grupo controle. O presente método, mesmo destituído de sensibilidade para aplicação em indivíduos normais, permite a quantificação deste esteróide em portadores de D21OH, com a sensibilidade e a especificidade necessárias para o diagnóstico e acompanhamento desta condição clínica.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Universidade Federal de São Paulo (UNIFESP) EPM Departamento de MedicinaHospital Infantil Darcy Vargas Serviço de Endocrinologia PediátricaHôpital Saint Louis Service de Biologie HormonaleUNIFESP, EPM, Depto. de MedicinaSciEL

    Rôle émergent des oestrogènes dans le cancer de la prostate (sulfate d'oestrone)

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    PARIS12-Bib. électronique (940280011) / SudocSudocFranceF

    The late Hauterivian Faraoni oceanic anoxic event in the western Tethys: Evidence from phosphorus burial rates

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    In the uppermost Hauterivian sediments of the western Tethys, a short-lived anoxic event (Faraoni event) is documented both in the form of an interval enriched in organic matter (pelagic realm) and in a condensed interval enriched in glauconite and phosphate (shelf realm). This latter interval represents the onset of a drowning episode on the Helvetic carbonate platform along the northern tethyan margin that lasted throughout the early Barremian. This drowning episode marks a turning point in the way the platform carbonate factory functioned: during the Hauterivian carbonate production was dominated by heterozoans, whereas during the late Barremian a photozoan assemblage developed that is preserved in the so-called Urgonian limestone. The late Hauterivian Faraoni oceanic anoxic event is of particular interest because it is not accompanied by a major positive shift in δ13C unlike other oceanic anoxic events during the Cretaceous (Valanginian, early Aptian, Cenomanian–Turonian boundary). We have analyzed four (hemi-)pelagic sections with regards to their phosphorus content to better understand the palaeoceanographic conditions related to this anoxic event and the associated changes in the shallow-water carbonate factory. The sections are located in Angles (SE France), Fiume-Bosso and Gorgo a Cerbara (central Italy), and Veveyse de Châtel-St. Denis (west Switzerland). We calculated phosphorus mass accumulation rates by using a cyclostratigraphic approach in order to obtain an adequate age model. We observe a comparable and correlatable long-term trend for the four sections, which suggests that the phosphorus mass accumulation rates and temporal changes therein are representative for the western tethyan pelagic realm. The Faraoni event is marked by a minimum in phosphorus accumulation and a positive shift in the Corg/Ptot ratios, which is interpreted as a reflection of the decreased capacity of storing and preserving phosphorus in oxygen-depleted sediments. Moreover, the onset in the decrease in phosphorus accumulation coincides with a sea level rise, while the Faraoni level itself corresponds to a maximum flooding interval. This phase of sea-level rise may have been important in the establishment of marine connections between the boreal and tethyan realms and, as such, in the exchange of nutrient-enriched waters. The model for the origin of the Faraoni oceanic anoxic event proposed here incorporates these aspects together with a positive feedback loop generated by phosphorus regeneration and a negative feedback loop related to changes in the ocean oxygen cycle. The subsequent long-term changes in phosphorus burial rates during the Barremian suggest that the Faraoni event marks the onset of a long period of environmental instability with regards to platform growth, leading to periodic phases of eutrophication and drowning of the northern tethyan carbonate platform. This environmental crisis ended during the late Barremian with the onset of the deposition of the Urgonian limestone under oligotrophic conditions

    Aging Male Questionnaire in normal and complaining men.

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    International audienceINTRODUCTION: Detection of androgen deficiency is at least, based on specific questionnaires, defined by sexual, psychological, and somatic variables. Their relationships with sexual hormone levels are poorly understood. AIM: To assess the Aging Male Symptoms (AMS) score and sex hormone levels in normal and complaining men in order to define the relationship between the key parameters related to androgen deficiency. METHODS: Nine hundred and three men were interviewed via phone by a trained interviewer who completed the questionnaire; 539 men consulting for a checkup in a health center and 471 complaining men, who completed the AMS scale in clinical setting, were selected, after excluding subjects with major and/or chronic diseases, endocrine disorders, psychological dysfunctions, and metabolic syndrome. MAIN OUTCOME MEASURES: Total AMS score and psychological, somatic and sexual subscores, as a function of age. RESULTS: The AMS questionnaires the were completed in a clinical setting or via calling-up line were comparable. In both cases, total AMS scores and subscores were significantly dependent of age and were correlated to income. In normal men, the only two parameters that significantly changed with age were the AMS sexual subscore and bioavailable testosterone (BT). Complaining men aged more than 50 years old had a significantly higher total AMS scores, subscores, and BT level than normal men up to 60 years old, and these differences weakened with increasing age. In normal and complaining men, whatever the AMS sexual subscore, any variation in testosterone (T) and BT levels was observed. CONCLUSIONS: The AMS scale could be defined as a screening test for androgen deficiency symptoms in men between 50 and 65 years of age. The sexual AMS subscore and BT level are the key variables to identify those symptoms; the severity of sexual symptoms can not be explained by a BT level decrease
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