RESUMEN
Levonorgestrel (LNG), a contraceptive progestin, exhibits, besides its progestational activity, other hormone-like effects at the peripheral level. To assess whether LNG and its metabolites exert androgenic and/or estrogenic actions at the central nervous system (CNS), their effects on male sexual behavior in castrated rats were examined. LNG, 5alpha-dihydro LNG (5alphaLNG), and the 3alpha,5alpha- and 3beta,5alpha-tetrahydro derivatives of LNG (3alphaLNG and 3betaLNG, respectively) were administered for 3 weeks either alone (1000 microg/day) or in combination (300 microg/day) with 5alpha-dihydrotestosterone (DHT, 300 microg/day) or with estradiol-17beta (E(2), 5 microg/day). Copulatory behavior was assessed twice per week and sex accessory organs weights recorded at the end of treatments. LNG restored full copulatory behavior comparable to that of testosterone treated animals, although with a slight delay, whereas 5alphaLNG induced male sexual behavior in a significantly lower number of subjects. 3betaLNG and 3alphaLNG induced mounting but failed to restore intromission and ejaculation. Combined LNG+E(2) treatment fully activated mounting and intromission, but ejaculation was only partially restored. Combined 5alphaLNG+E(2) treatment and the combinations of 3alphaLNG or 3betaLNG with E(2) were significantly less effective, activating fewer intromissions and ejaculations. 3alphaLNG and 5alphaLNG, in combination with DHT, restored male sexual behavior. LNG, but not its metabolites, induced a significant increase on the weight of sex accessory organs. The overall results demonstrated that high doses of LNG induce a potent androgen agonistic behavioral effect and that its A-ring reduction diminishes this potency and enables a shift towards a weak estrogen-like effect.
Asunto(s)
Hormonas Esteroides Gonadales/metabolismo , Hormonas Esteroides Gonadales/farmacología , Levonorgestrel/metabolismo , Levonorgestrel/farmacología , Conducta Sexual Animal/efectos de los fármacos , Andrógenos/metabolismo , Andrógenos/farmacología , Animales , Estrógenos/metabolismo , Estrógenos/farmacología , Femenino , Masculino , Ratas , Ratas Wistar , Conducta Sexual Animal/fisiologíaRESUMEN
Levonorgestrel (13beta-ethyl-17alpha-ethynyl-17beta-hydroxy-4-gonen-3-one), a potent contraceptive progestin stimulates growth and proliferation of cultured breast cancer cells through a receptor-mediated mechanism, even though levonorgestrel does not bind to the oestrogen receptor (ER). To assess whether the oestrogen-like effects induced by this synthetic progestin are exerted via its metabolic conversion products, we studied the binding affinity of three A-ring levonorgestrel derivatives to the ER and their capability to transactivate an oestrogen-dependent yeast system co-transfected with the human ER gene and oestrogen responsive elements fused to a beta-galactosidase reporter vector. The results demonstrated that the 3beta,5alpha reduced levonorgestrel derivative and to a lesser extent its 3alpha isomer interact with the oestrogen receptor, with a significantly lower relative binding affinity (2.4% and 0.4%, respectively) than that of oestradiol (100%), while levonorgestrel does not. Both levonorgestrel metabolites were able to activate, in a dose-dependent manner, the beta-galactosidase reporter gene in the yeast expression system, an effect that was precluded by a steroidal antioestrogen. The oestrogenic potency of levonorgestrel metabolites was significantly lower (750-fold) than that of oestradiol. Furthermore, high doses of 3beta,5alpha levonorgestrel (2.5 mg/day/6 days) induced an increase of oestrogen-dependent progestin receptor in the anterior pituitary of castrated rats. The overall data offer a plausible explanation for the weak oestrogenic effects induced by high, non-pharmacological doses of levonorgestrel.
Asunto(s)
Anticonceptivos Femeninos/farmacología , Estrógenos/farmacología , Levonorgestrel/farmacología , Animales , Unión Competitiva , Anticonceptivos Femeninos/metabolismo , Relación Dosis-Respuesta a Droga , Estradiol/análogos & derivados , Estradiol/farmacología , Antagonistas de Estrógenos/farmacología , Estrógenos/metabolismo , Femenino , Fulvestrant , Humanos , Levonorgestrel/análogos & derivados , Levonorgestrel/metabolismo , Adenohipófisis/efectos de los fármacos , Adenohipófisis/metabolismo , Ratas , Ratas Wistar , Receptores de Estrógenos/genética , Receptores de Estrógenos/metabolismo , Receptores de Progesterona/efectos de los fármacos , Receptores de Progesterona/metabolismo , Proteínas Recombinantes de Fusión/efectos de los fármacos , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/metabolismo , Saccharomyces cerevisiae/genética , beta-Galactosidasa/efectos de los fármacos , beta-Galactosidasa/genética , beta-Galactosidasa/metabolismoRESUMEN
Gestodene (13beta-ethyl-17alpha-ethynyl-17beta-hydroxy-4,5-gonadien-3-one), the most potent progestin ever synthesized, stimulates breast cancer cell growth through an oestrogen receptor-mediated mechanism, and its use in hormonal contraception has been associated with side effects attributable to oestrogenic actions. These observations have remained controversial, since gestodene does not bind to the oestrogen receptor or exert oestrogen-like activities. Recently, we have demonstrated that non-phenolic gestodene derivatives interact with oestrogen receptors and induce oestrogenic effects in cell expression systems. To assess whether gestodene is biotransformed to metabolites with intrinsic oestrogenic potency, [3H]- and [14C]-labelled gestodene were incubated in vitro with rat anterior pituitary, hypothalamus and ventral prostate homogenates under different experimental conditions. The most remarkable finding was the isolation and identification of 3beta,5alpha-tetrahydrogestodene and 3alpha,5alpha-tetrahydrogestodene as metabolic conversion products of gestodene, presumably with 5alpha-dihydrogestodene as intermediate. The overall results seem to indicate that the weak oestrogenic effects attributable to gestodene could be mediated by its tetrahydro metabolites.
Asunto(s)
Hipotálamo/metabolismo , Norpregnenos/química , Norpregnenos/metabolismo , Adenohipófisis/metabolismo , Próstata/metabolismo , 3-Oxo-5-alfa-Esteroide 4-Deshidrogenasa/metabolismo , Animales , Biotransformación , Anticonceptivos Sintéticos Orales/química , Anticonceptivos Sintéticos Orales/metabolismo , Anticonceptivos Sintéticos Orales/farmacocinética , Femenino , Concentración de Iones de Hidrógeno , Hipotálamo/enzimología , Masculino , NADP/metabolismo , Norpregnenos/farmacocinética , Adenohipófisis/enzimología , Congéneres de la Progesterona/química , Congéneres de la Progesterona/metabolismo , Congéneres de la Progesterona/farmacocinética , Próstata/enzimología , Ratas , Ratas Wistar , Testosterona/metabolismoRESUMEN
Gestodene (17 alpha-ethynyl-13 beta-ethyl-17 beta-hydroxy-4, 15-gonadien-3-one) is the most potent synthetic progestin currently available and it is widely used as a fertility regulating agent in a number of contraceptive formulations because of its high effectiveness, safety and acceptability. The observation that contraceptive synthetic progestins exert hormone-like effects other than their progestational activities, prompted us to investigate whether gestodene (GSD) administration may induce oestrogenic effects, even though the GSD molecule does not interact with intracellular oestrogen receptors (ER). To assess whether GSD may exert oestrogenic effects through some of its neutral metabolites, a series of experimental studies were undertaken using GSD and three of its A-ring reduced metabolites. Receptor binding studies by displacement analysis confirmed that indeed GSD does not bind to the ER, whereas its 3 beta,5 alpha-tetrahydro reduced derivative (3 beta GSD) interacts with a relative high affinity with the ER. The 3 alpha,5 alpha GSD isomer (3 alpha GSD) also binds to the ER, though to a lesser extent. The ability of the A-ring reduced GSD derivatives to induce oestrogenic actions was evaluated by the use of two different molecular bioassays: (a) transactivation of a yeast system co-transfected with the human ER alpha (hER alpha) gene and oestrogen responsive elements fused to the beta-galactosidase reporter vector and (b) transactivation of the hER alpha-mediated transcription of the chloramphenicol acetyl transferase (CAT) reporter gene in a HeLa cells expression system. The oestrogenic potency of 3 beta GSD was also assessed by its capability to induce oestrogen-dependent progestin receptors (PR) in the anterior pituitary of castrated female rats. The results demonstrated that 3 beta GSD and 3 alpha GSD were able to activate, in a dose-dependent manner, the hER alpha-mediated transcription of both the beta-galactosidase and the CAT reporter genes in the yeast and HeLa cells expression systems respectively. In both assays the 3 beta derivative of GSD exhibited a significantly greater oestrogenic effect than its 3 alpha isomer, while unchanged GSD and 5 alpha GSD were completely ineffective. Neither 3 beta GSD nor 3 alpha GSD exhibited oestrogen synergistic actions. Interestingly, the pure steroidal anti-oestrogen ICI-182,780 diminished the transactivation induced by 3 beta GSD and 3 alpha GSD in the yeast expression system. Furthermore, administration of 3 beta GSD resulted in a significant increase of oestrogen-dependent PR in the anterior pituitaries of castrated rats in comparison with vehicle-treated animals. The characteristics of the 3 beta GSD-induced PR were identical to those induced by oestradio benzoate. The overall results demonstrate that 3 beta GSD and its 3 alpha isomeric alcohol specifically bind to the ER and possess a weak intrinsic oestrogenic activity, whereas unmodified GSD does not. The data contribute to a better understanding of the GSD mechanism of action and allow the hypothesis to be advanced that the slight oestrogenlike effects attributable to GSD are mediated by its non-phenolic, tetrahydro reduced metabolites.
Asunto(s)
Anticonceptivos Sintéticos Orales/farmacología , Norpregnenos/farmacología , Congéneres de la Progesterona/farmacología , Animales , Unión Competitiva , Anticonceptivos Sintéticos Orales/metabolismo , Femenino , Células HeLa , Humanos , Norpregnenos/metabolismo , Oxidación-Reducción , Adenohipófisis/efectos de los fármacos , Adenohipófisis/metabolismo , Congéneres de la Progesterona/metabolismo , Ratas , Ratas Wistar , Receptores de Estradiol/metabolismo , Receptores de Progesterona/biosíntesis , Saccharomyces cerevisiae/genética , Activación Transcripcional/efectos de los fármacosAsunto(s)
Servicios de Planificación Familiar/historia , Libertad , Derechos de la Mujer/historia , Servicios de Planificación Familiar/tendencias , Femenino , Predicción , Historia del Siglo XX , Humanos , México , Atención Perinatal/historia , Medicina Reproductiva , Factores de Tiempo , Salud de la Mujer , Derechos de la Mujer/tendenciasRESUMEN
In the last decades has been a worldwide trend to increase the number of cesarean sections as an alternative of obstetric resolution, phenomenon for which it was proposed a variety of explanation, this fact remains practically unknown in the institutions of the National Health System (NHS) in Mexico. To identify the trend of the pregnancy to end for cesarean sections during the years of 1991-1995 in the 32 states of de country, as well as of all the institutions of the National Health System. Descriptive, cross sectional and retrospective. We use the data of the Bureau of Statistics and Informatics of de Health Ministry of each one of the 32 states of the country, of the years 1991 to 1995, and of the number of cesarean sections made in the hospitals of the different institutions of the NHS. We started off with a data-base, to calculate frequency tables, and the specific rate of the cesarean section for each year, for each one of the states and institutions of the NHS. We calculate the secular trends using the annual rates of cesarean section, for each one of the states and institutions of the NHS. We also made bivariate analysis and estimated the odds ratio (OR) and 95% Confidence Interval (95% IC); and the statistic X2 for trend, setting the two tailed statistic significance level of 0.05. During the study period, there was 7,503,817 births in all hospitals of the NHS, of these births 1,929,865 (25.72%) was resolved by cesarean section. For the whole period it there was a clear trend to increment of the cesarean section, the rate for 1991 was 20.44%, and by 1995 was 28.58%, the raise for the period was 39.82%, with values of the OR for trend of 1.56; 95% IC (1.55-1.57). "P" < 0.05. The rate for institutions attending open population had an increment of 35.08% [OR trend 1.45; 95% IC (1.43-1.46), "p" < 0.05], of them the highest rate was for the State System of Health in 1995 with 29.78%, the rates for the remaining institutions varied from 16.57% for the IMSS/SOLIDARIDAD and 21.7% for the Health Ministry, all trends were statistically significant. In relation to the institutes attending closed population the raise was of 53.27% [OR trend 1.82; 95% IC (1.81-1.83), "p" < 0.05], with the highest rate for the National Defense Ministry which had a rate of 51-15%, the rates for the remaining institutions varied from 33.52% for the Mexican Institute of Social Security (IMSS) to 43.89% for the Institute of Safety and Social Services for the State Workers (ISSSTE), with exception of the Management of the Medical Services of the Mexican Oils (PEMEX) and the Marine Ministry (SECMAR), all trends were statistically significant. When the analysis of the cesarean section rates for the 32 states of the Mexican Republic was carried out, we found that in 1995, the national average rate was 28.58%, the lowest rate corresponded to the state of Zacatecas with 19.82% and the highest to the state of Nuevo León with 42.14%. There was a tendency to increment for all states which varied from 23.55% for the state Chiapas and 67.97% for the states of Querétaro, all increments were statistically significant. We conclude, that rates of cesarean section for both, institutions of NHS and states of the Mexican Republic, are of the highest in the world, no matter what big the interinstitutional and interstate variation are. The highest rates occurred in institutions attending closed population, and the states with a higher degree of socioeconomic development.
Asunto(s)
Cesárea/tendencias , Cesárea/estadística & datos numéricos , Distribución de Chi-Cuadrado , Intervalos de Confianza , Estudios Transversales , Femenino , Humanos , Modelos Lineales , México , Programas Nacionales de Salud/estadística & datos numéricos , Oportunidad Relativa , Embarazo , Estudios RetrospectivosRESUMEN
OBJECTIVE: To report the experience, obstacles, and strategies of screening for congenital hypothyroidism. SETTING: Newborns in Mexico. METHODS: Thyroid stimulating hormone (TSH) was measured by enzyme immunoassay using commercial kits in 1,140,364 newborns. RESULTS: There were 464 positive cases, of whom 299 (64.4%) were girls. 236 (50.9% showed ectopic nodules, 202 (43.5%) thyroid agenesis, 21 (4.5%) dyshormonogenesis, and 5 (1.1%) an unclassified goitre. The false positive rate was 0.024% and there were 11 false negative results. Currently, 600,000 (26%) of the 2,300,000 newborns are screened. This percentage has been increased in recent years by taking samples from cord blood and will be increased further by starting congenital hypothyroidism screening at social security units and by midwives screening infants born at home. CONCLUSIONS: Mental retardation in infants in developing countries can be reduced by neonatal screening, and carefully planned strategies can steadily extend the benefits of screening.
Asunto(s)
Hipotiroidismo Congénito , Hipotiroidismo/diagnóstico , Tamizaje Neonatal , Recolección de Muestras de Sangre/métodos , Reacciones Falso Positivas , Femenino , Sangre Fetal/química , Humanos , Hipotiroidismo/epidemiología , Recién Nacido , Estudios Longitudinales , Masculino , México/epidemiología , Tamizaje Neonatal/métodos , Tamizaje Neonatal/organización & administración , Tamizaje Neonatal/normas , Prevalencia , Distribución por Sexo , Glándula Tiroides/anomalías , Tirotropina/sangreRESUMEN
This is an analysis of the characteristics of cesarean section operations within the Ministry of Health (SSA) and the implications in relation to maternal and perinatal mortality during the five year period from 1990 to 1995. A descriptive study was undertaken based on cesarean section information obtained from the Statewide (Reporting) System of Basic Information (SEIR) and based on maternal and perinatal mortality information provided by the Ministry's Internal Hospital Committees from 1990 to 1995. This information was analyzed as a chronological series in order to compare the changes in the annual cesarean rates at both national and statewide levels. The Pearson test was used to determine the correlation between the frequency of cesarean sections and maternal and perinatal mortality rates during the same period within a 95 percent confidence interval (p < 0.05). The frequency of cesarean sections was shown to have increased within the SSA hospital system as whole and when considering each state separately. A positive and statistically significant correlation was observed between the frequency of cesarean sections and maternal mortality rates, while the increase in cesarean rates demonstrated no relationship with perinatal mortality rates. The increase in cesarean section rates in the Ministry of Health during the period analyzed exceeded any potential benefits and could have contributed to the increase in maternal morbidity and morbility as well as hospital cost. This increase is worrisome due to the projected tendency for the rates to continue to increase in the next few years if quick and concrete actions are not taken in order to decrease these rates.
Asunto(s)
Cesárea/clasificación , Cesárea/normas , Femenino , Humanos , México , Embarazo , Garantía de la Calidad de Atención de SaludRESUMEN
A large introductory study of Cyclofem, a once-a-month injectable contraceptive, was conducted in three Mexican provinces. A total of 3457 healthy women participated: 640 women from rural areas (community-based component) and 2817 women from urban and suburban areas (health center-based component). A total of 20,316 women-months of treatment experience were accumulated during a one year period. Cyclofem proved its use-effectiveness (pregnancy rate of 0.03%) and its safety under routine service conditions of family planning facilities in Mexico. The overall life table continuation rate at 1 year was 26.1%. Higher continuation rates were observed in the community-based component (36.6%) as compared to the health center component (23.7%). The most common reason for method discontinuation was change of address. Only 15% of the discontinuations were attributable to the injectable contraceptive method, with the overall 1 year discontinuation rate for bleeding problems (including amenorrhea) was < 11%. These observations underscore the importance of appropriate counseling and follow-up measures, providing convenient access to repeat injections, and other service delivery issues related to continuation of Cyclofem. The results of this trial have once again demonstrated that Cyclofem is a highly effective method with an acceptable side effect profile. In addition, the study provided the elements for its approval by local health authorities and its inclusion into the Ministry of Health Family Planning Program.
PIP: The effectiveness and continuation rates associated with the once-a-month injectable contraceptive Cyclofem were investigated in an introductory trial conducted in three Mexican provinces (Sinaloa, Guanajuato, and Veracruz). Cyclofem contains 25 mg of medroxyprogesterone acetate and 5 mg of estradiol cypionate. A total of 3457 women (640 women from rural communities and 2817 from urban and suburban family planning centers) were enrolled and 20,316 woman-months of treatment experience were accumulated during the 12-month study period. The mean age of study participants was 23.6 years; 70% had previously used at least one contraceptive method. There was only one pregnancy (rate, 0.03%). The overall life-table continuation rate at 1 year was 26.1%, but this rate was higher in the community-based group (36.9%) than in the health center group (22.4%). This discrepancy is presumed to reflect the greater access of clinic clients to other contraception options. Continuation was highest among women 30-34 years of age, those with low levels of education, women with five or more children, and those who did not want more children. Only 14% of discontinuations were method-related. The 1-year discontinuation rate for bleeding problems, including amenorrhea, was 10.2%. These findings indicate Cyclofem is a safe, effective method appropriate for inclusion in Mexico's Ministry of Health Family Planning Program.
Asunto(s)
Anticonceptivos Femeninos , Estradiol/análogos & derivados , Acetato de Medroxiprogesterona/administración & dosificación , Adolescente , Adulto , Anticonceptivos Orales Combinados/administración & dosificación , Anticonceptivos Orales Combinados/efectos adversos , Combinación de Medicamentos , Escolaridad , Estradiol/administración & dosificación , Estradiol/efectos adversos , Femenino , Humanos , Inyecciones Intramusculares , Acetato de Medroxiprogesterona/efectos adversos , México , Satisfacción del Paciente , Estudios ProspectivosRESUMEN
In Mexico, as in almost all the Latin American countries, abortion represents an important maternal morbidity-mortality reason. It has been pointed out that those women who had an abortion, are in greater risk to repeat this condition than those women who have not had the episode. For this reason, it is a transcendental matter, the use of modern contraceptive technology for fertility regulation with the aim to avoid not planned pregnancies and their devastating consequences. This document reviews-according to the Family Planning Official Norm of the Ministry of Health-those different contractive alternatives, that can be used in the postabortion.
Asunto(s)
Anticoncepción , Aborto Inducido , Anticonceptivos Orales Combinados/administración & dosificación , Anticonceptivos Sintéticos Orales/administración & dosificación , Servicios de Planificación Familiar , Femenino , Humanos , Dispositivos Intrauterinos , Levonorgestrel/administración & dosificación , Congéneres de la Progesterona/administración & dosificación , Progestinas/administración & dosificaciónRESUMEN
BACKGROUND AND OBJECTIVE: Male pseudohermaphroditism due to 5 alpha-reductase deficiency was originally described in 1974. Recently, 5 alpha-reductase Type 2 gene defects have been found generally to be due to point mutations within the 5 exons of the 5 alpha-reductase-2 gene. In this report, we describe the molecular study of patients with 5 alpha-reductase deficiency. DESIGN: Previously diagnosed patients with 5 alpha-reductase deficiency were sampled in order to perform molecular studies. PATIENTS: Eight 5 alpha-reductase deficient individuals from 6 unrelated families. MEASUREMENTS: Single-strand conformational polymorphism and DNA sequencing were performed after polymerase chain reaction amplification of each of the 5 exons of the gene. RESULTS: Five different missense mutations were found. In 4 patients a cytosine to guanine substitution was observed at codon 212 in exon 4. Two siblings presented a cytosine to adenine substitution at codon 207 in exon 4. Another patient exhibited a guanine to adenine substitution at codon 34 in exon 1, whilst one individual presented 2 mutations: a guanine to adenine substitution at codon 115 in exon 2 and a guanine to adenine substitution at codon 203 in exon 4 (previously undescribed mutation). CONCLUSIONS: The presence of the same mutation in 4 patients from 3 families indicates the increased prevalence of this mutation in a particular ethnic group, suggesting a common ancestry for the gene defect in these patients. The existence of hot spots is supported by the mutations in codons 34 and 207 which have also been found in other ethnic groups. Interestingly, the patient who presented 2 different mutations, one of them previously undescribed, was reared as a male and exhibited a more masculine phenotype. Further studies in patients with this and other mutations will be needed to verify genotype-phenotype correlation.
Asunto(s)
3-Oxo-5-alfa-Esteroide 4-Deshidrogenasa/deficiencia , 3-Oxo-5-alfa-Esteroide 4-Deshidrogenasa/genética , Trastornos del Desarrollo Sexual/genética , Mutación Puntual , Adolescente , Adulto , Trastornos del Desarrollo Sexual/etnología , Exones/genética , Humanos , Masculino , México/etnología , Linaje , Reacción en Cadena de la Polimerasa , Polimorfismo Conformacional Retorcido-Simple , Análisis de Secuencia de ADNRESUMEN
Norethisterone (NET), a 19-nor synthetic progestin, undergoes enzyme-mediated 5alpha-reduction and exerts potent androgenic effects in target organs. To investigate its mode of androgenic action we examined, in a comparative manner, the in vitro metabolism of NET and testosterone (T), as well as the binding affinities to androgen receptors (AR) and the androgenic potency of NET, T, and their 5alpha-reduced derivatives. Bioconversion of [3H]-NET and [3H]-T was studied in rat prostate homogenates, AR binding affinity was assessed in rat ventral prostates using [3H]-mibolerone as the radioligand, and the androgenic potency was evaluated by the increase of beta-glucuronidase activity in the mouse kidney, and by the growth of accessory sex organs in castrated male rats. The results demonstrated that 5alpha-NET displayed a higher AR binding affinity but a significantly lower androgenic potency than unchanged NET. The bioconversion studies indicated that the metabolism of NET was similar to that of T, although to a lesser extent, thus ruling out the possibility that the synthetic progestin metabolizes rapidly into less active derivatives. To investigate the nature of the paradoxical effect of 5alpha-reduction upon the NET molecule, the interaction with AR and the androgenic potency of T, 19-nortestosterone (19norT), 17alpha-ethynyl testosterone (ET) and their 5alpha-reduced derivatives were examined. The results of AR binding studies revealed that 5alpha-reduction of T and ET significantly enhanced their affinities, and that the 5alpha-derivative of 19norT displayed a similar binding affinity to that exhibited by 19norT. In terms of biological activity, the results showed that 5alpha-reduction of T and 19norT significantly increased their androgenic potency, whereas 5alpha-reduction of ET resulted in a significant diminution of its androgenicity in a manner similar to that observed with the 5alpha-reduction of NET. When NET and 19norT were simultaneously administered with 5alpha-dihydrotestosterone they exhibited a potent synandrogenic activity, an effect that was cancelled by their 5alpha-reduction. Interestingly, ET displayed an antiandrogenic activity, an effect that was also suppressed by its 5alpha-reduction. The overall results demonstrated a distinctive, paradoxical effect of 5alpha-reduction upon the NET molecule, which was different from that seen in naturally occurring androgens, and which suggests that the presence of the 17alpha-ethynyl group plays a key role in this phenomenon. The data provided further evidence that the metabolism of synthetic contraceptive progestins modulates the expression of their hormone-like actions.
Asunto(s)
Glucuronidasa/metabolismo , Noretindrona/metabolismo , Noretindrona/farmacología , Receptores Androgénicos/metabolismo , Andrógenos/fisiología , Animales , Unión Competitiva , Relación Dosis-Respuesta a Droga , Sinergismo Farmacológico , Etisterona/metabolismo , Etisterona/farmacología , Glucuronidasa/efectos de los fármacos , Riñón/efectos de los fármacos , Riñón/metabolismo , Masculino , Ratones , Ratones Endogámicos BALB C , Nandrolona/análogos & derivados , Nandrolona/metabolismo , Nandrolona/farmacología , Noretindrona/análogos & derivados , Orquiectomía , Tamaño de los Órganos/efectos de los fármacos , Oxidación-Reducción , Congéneres de la Progesterona/metabolismo , Próstata/efectos de los fármacos , Próstata/crecimiento & desarrollo , Próstata/metabolismo , Ratas , Ratas Wistar , Vesículas Seminales/efectos de los fármacos , Vesículas Seminales/crecimiento & desarrollo , Relación Estructura-Actividad , Testosterona/análogos & derivados , Testosterona/metabolismo , Testosterona/farmacología , TritioAsunto(s)
Salud , Reproducción , Adolescente , Adulto , Servicios de Planificación Familiar , Femenino , Humanos , América Latina , Masculino , México , EmbarazoRESUMEN
True hermaphroditism is characterized by the development of ovarian and testicular tissue in the same individual. Müllerian and Wolffian structures are usually present, and external genitalia are often ambiguous. The most frequent karyotype in these patients is 46,XX or various forms of mosaicism, whereas 46,XX is very rarely found. The phenotype in all these subjects is similar. We studied 10 true hermaphrodites. Six of them had a 46,XX chromosomal complement: 3 had been reared as males and 3 as females. The other 4 patients were mosaics: 3 were 46,XX/46,XY and one had a 46,XX/47,XXY karyotype. One of the 46,XX/46,XY mosaics was reared as a female, whereas the other 3 mosaics were reared as males. The sex of assignment in the 10 patients depended only on labio-scrotal differentiation. Molecular studies in 46,XX subjects documented the absence of Y centromeric sequences in all cases, arguing against hidden mosaicism. One patient presented Yp sequences (ZFY+, SRY+), which contrast with South African black 46,XX true hermaphrodites in whom no Y sequences were found. Molecular analysis in the subjects with mosaicism demonstrated the presence of Y centromeric and Yp sequences confirming the presence of a Y chromosome. Gonadal development, endocrine function, and phenotype in the 10 patients did not correlate with the presence of a Y chromosome or Y-derived sequences in the genome, confirming that true hermaphroditism is a heterogeneous condition.
Asunto(s)
Trastornos del Desarrollo Sexual/genética , Proteínas Nucleares , Factores de Transcripción , Cromosoma Y , Adolescente , Adulto , Niño , Preescolar , Proteínas de Unión al ADN/genética , Femenino , Disgenesia Gonadal 46 XY , Humanos , Lactante , Cariotipificación , Factores de Transcripción de Tipo Kruppel , Masculino , Fenotipo , Análisis para Determinación del Sexo , Proteína de la Región Y Determinante del SexoRESUMEN
The 5 alpha-reduction of levonorgestrel (LNG) as well as its binding capacity to the androgen receptors of the hamster flank organ were investigated. Furthermore, the effects of LNG and its 5 alpha-reduced metabolite in the flank organ test and on [U-14C]glucose incorporation into lipids by this tissue were determined. Homogenates from female hamster flank organs were incubated in the presence of [3H]LNG at pH 7.4. The radioactive 5 alpha-LNG metabolite was isolated and its purity was assessed. Competition experiments for androgen binding receptors were carried out with 1.38 nM [3H-7 alpha-17 alpha]dimethyl-19- nortestosterone (DMNT), Kd, plus a range of increasing concentrations of the different unlabeled steroid hormones. The flank organ test was performed in vivo, and [U-14C]glucose incorporation into lipids was determined under organ culture conditions. The 5 alpha-LNG had the same binding capacity to androgen receptors (AR) as LNG in male flank organs. The flank organ test demonstrated that 5 alpha-LNG activity was similar to that observed for levonorgestrel and testosterone (T) on gonadectomized male hamster flank organs. Topical applications of LNG or 5 alpha-LNG increased [U-14C]glucose incorporation into lipids in a way similar to that of T. The overall data indicate that LNG and 5 alpha-LNG produced androgenic activity in the lipid pathway of male flank organs, and that 5 alpha-reduction is not essential for the LNG effect on this tissue.
Asunto(s)
Levonorgestrel/metabolismo , Receptores Androgénicos/metabolismo , Glándulas Sebáceas/metabolismo , Animales , Unión Competitiva , Castración , Cricetinae , Femenino , Glucosa/metabolismo , Técnicas In Vitro , Levonorgestrel/química , Metabolismo de los Lípidos , Masculino , Oxidación-Reducción , Glándulas Sebáceas/efectos de los fármacos , Testosterona/farmacologíaRESUMEN
Progesterone (P4) and its metabolites are involved in several functions of the central nervous system (CNS). These steroids participate in neuronal excitability, reproduction and sexual behavior. P4 and its metabolites exert their effects on neurons and glial cells through several mechanisms that include the interaction of the steroids with: 1) intracellular specific receptors; 2) modulatory sites located in neurotransmitter receptors; and 3) ionic channels. By these mechanisms, modifications in gene expression, second messengers' production and ion conductance are induced. The activities of the P4 metabolites have been mainly related to membrane effects, whereas for P4, the transcriptional and translational effects are mediated by intracellular receptors. Thus, these steroids can modify the CNS functions at short (milliseconds), medium (minutes) or long term (hours or days) lapses. The knowledge of the molecular mechanisms involved in the actions of P4 and its metabolites in the CNS will contribute to the understanding of fundamental biological processes such as sexual behavior and reproduction, and it will open the possibility of alternative therapies in the treatment of some neurologic and psychiatric disorders such as epilepsy, anxiety, premenstrual syndrome, and cerebral tumors which possess hormonal regulation.
Asunto(s)
Sistema Nervioso Central/fisiología , Progesterona/fisiología , Animales , Estradiol/fisiología , Regulación de la Expresión Génica/fisiología , Humanos , Canales Iónicos/fisiología , Progesterona/metabolismo , Receptores de Progesterona/fisiología , Reproducción/fisiología , Transducción de Señal/fisiología , Transmisión Sináptica/fisiologíaRESUMEN
In the present study, we describe the clinical, endocrinological, psychosexual and biochemical features of 7 Mexican male pseudohermaphrodites with primary 5 alpha-reductase deficiency in whom heterogeneity in the pattern of gender identity change at puberty was observed. The patients belonged to 5 different pedigrees from diverse locations in Mexico. Six of them were admitted to the Hospital during or after puberty. The one prepubertal subject was the sibling of a previously studied patient. Basal serum gonadotropins were determined by double antibody radioimmunoassay. Basal and choriogonadotropin (CG)-stimulated concentrations of androstenedione (A), testosterone (T) and dihydrotestosterone (DHT) were determined by radioimmunoassay after extraction and separation by celite chromatography. Urinary aetiocholanolone, androsterone and C19 and C21 5 beta/5 alpha metabolite ratios were analyzed by capillary gas chromatography. Enzyme activity and androgen receptors were studied in fibroblasts cultured from genital skin. Psychological assessment was performed using the Bender-Gestalt Wechsler Adult Intelligence Scale, the Rorschach Ink Blot and the Thematic Apperception Tests. All 7 patients were unambiguously reared as females; three spontaneously changed their gender identity and role from female to male after puberty, another one changed during psychotherapy at the end of puberty. Two patients (one prepubertal and the other pubertal) have been under therapy during 1.5 years, but due to familial and social factors a female gender has prevailed. The remaining patient consulted at age 15 because of virilization; her female gender identity did not change after more than one year of treatment and due to the fact she was depressed and had suicidal tendencies, the penis and testes were removed.(ABSTRACT TRUNCATED AT 250 WORDS)
Asunto(s)
3-Oxo-5-alfa-Esteroide 4-Deshidrogenasa/deficiencia , Trastornos del Desarrollo Sexual/enzimología , Trastornos del Desarrollo Sexual/psicología , Identidad de Género , Adolescente , Adulto , Niño , Hormona Folículo Estimulante/sangre , Humanos , Inteligencia , Hormona Luteinizante/sangre , Masculino , México , Linaje , PubertadRESUMEN
Norethisterone (NET) is a synthetic progestin, used as a contraceptive agent, that is biotransformed at target tissues into 5 alpha-NET and 3 beta,5 alpha-NET, which possess different pharmacological properties. The effects of these metabolites on the expression of uteroglobin (UG) and progesterone receptor (PR) genes, both regulated by progesterone (P4), were evaluated in the uterus of prepubertal female rabbits that were simultaneously treated with P4 (1.0 mg) for 5 consecutive days. As determined by Western and Northern blot analyses, 5 alpha-NET inhibited the P4-induced UG gene expression in a dose-dependent manner. A similar inhibition was observed with the administration of RU-486. The estrogenic agent 3 beta,5 alpha-NET and estradiol at a dose of 1.0 mg also inhibited the UG gene expression induced by P4. Both 5 alpha-NET and 3 beta,5 alpha-NET blocked the PR down-regulation induced by P4 as assessed by Western and Northern blot methods. The inhibition of UG synthesis and PR down-regulation by 5 alpha-NET and 3 beta,5 alpha-NET indicates that these NET metabolites possess antiprogestational properties.