Hypothalamic-pituitary-ovarian axis in thyroid dysfunction / El eje hipotalámico-pituitario-ovárico en la disfunción tiroidea

BACKGROUND: It has been established that thyroid dysfunction causes impairment of reproductive function. However, laboratory and human studies that associated this with female reproductive hormones are conflicting and data reporting the effects of thyroid dysfunction on reproductive organs are insufficient. AIM: This study investigated the effect of experimental hypothyroidism and hyperthyroidism on hypothalamic-pituitary-ovarian axis and reproductive organs morphometry and histology in female rats. METHODS: Laboratory animals were randomized into one of the three groups: control, carbimazole-induced hypothyroidism and levothyroxine-induced hyperthyroidism. RESULTS: Organ morphometry and serum follicle stimulating hormone (FSH) were statistically comparable across all groups. Serum progesterone increased in hypothyroid rats but was reduced in hyperthyroid rats when compared with the control (p < 0.05). Body weight gain, serum luteinizing hormone and oestradiol were significantly reduced in both hypothyroid and hyperthyroid states when compared to the control. Hypothyroidism and hyperthyroidism also led to alterations in organ cytoarchitecture. CONCLUSION: Findings from this study suggest that impairment ofreproductive function associated with thyroid dysfunction is attendant with derangement of hormonal milieu and alteration in reproductive organs cytoarchitecture. Luteinizing hormone and oestradiol are implicated.

ANTECEDENTES: Se ha establecido que la disfunción de la tiroides causa deterioro de la función reproductiva. Sin embargo, los estudios humanos y de laboratorio que asociaban tal disfunción a las hormonas reproductoras femeninas son contradictorios, y los datos que reportan los efectos de la disfunción tiroidea sobre los órganos reproductores son insuficientes. OBJETIVO: Este estudio investigó el efecto del hipotiroidismo y el hipertiroidismo experimentales sobre el eje hipotalámico-pituitario-ovárico, y la morfometría e histología de los órganos reproductores en ratas hembras. MÉTODOS: Los animales de laboratorio fueron asignados al azar a uno de estos tres grupos: control, hipotiroidismo inducido por carbimazol, e hipertiroidismo inducido por levotiroxina. RESULTADOS: La morfometría de los órganos y hormona folículo-estimulante (FSH) en suero, fueron estadísticamente comparables en todos los grupos. La progesterona sérica aumentó en las ratas hipotiroideas, pero se redujo en las ratas hipertiroideas en comparación con el grupo de control (p < 0.05). El aumento de peso corporal, la hormona luteinizante en suero, y el estradiol se redujeron significativamente tanto en condiciones de hipotiroidismo como en estado de hipertiroidismo, en comparación con el grupo control. El hipotiroidismo y el hipertiroidismo condujeron también a alteraciones en la citoarquitectura de los órganos. CONCLUSIÓN: Resultados de este estudio sugieren que la debilitación de la función reproductora asociada con la disfunción de la tiroides, va acompañada de trastornos del medio hormonal, e implica alteraciones de la citoarquitectura de los órganos reproductores, la hormona luteinizante, y el estradiol.

Roles of estrogen and progesterone in modulating renal nerve function in the rat kidney

The maintenance of extracellular Na+ and Cl- concentrations in mammals depends, at least in part, on renal function. It has been shown that neural and endocrine mechanisms regulate extracellular fluid volume and transport of electrolytes along nephrons. Studies of sex hormones and renal nerves suggested that sex hormones modulate renal function, although this relationship is not well understood in the kidney. To better understand the role of these hormones on the effects that renal nerves have on Na+ and Cl- reabsorption, we studied the effects of renal denervation and oophorectomy in female rats. Oophorectomized (OVX) rats received 17β-estradiol benzoate (OVE, 2.0 mg·kg-1·day-1, sc) and progesterone (OVP, 1.7 mg·kg-1·day-1, sc). We assessed Na+ and Cl- fractional excretion (FENa+ and FECl- , respectively) and renal and plasma catecholamine release concentrations. FENa+ , FECl- , water intake, urinary flow, and renal and plasma catecholamine release levels increased in OVX vs control rats. These effects were reversed by 17β-estradiol benzoate but not by progesterone. Renal denervation did not alter FENa+ , FECl- , water intake, or urinary flow values vs controls. However, the renal catecholamine release level was decreased in the OVP (236.6±36.1 ng/g) and denervated rat groups (D: 102.1±15.7; ODE: 108.7±23.2; ODP: 101.1±22.1 ng/g). Furthermore, combining OVX + D (OD: 111.9±25.4) decreased renal catecholamine release levels compared to either treatment alone. OVE normalized and OVP reduced renal catecholamine release levels, and the effects on plasma catecholamine release levels were reversed by ODE and ODP replacement in OD. These data suggest that progesterone may influence catecholamine release levels by renal innervation and that there are complex interactions among renal nerves, estrogen, and progesterone in the modulation of renal function.

Influencia de las hormonas sexuales en mujeres con esclerosis múltiple durante la memoria de trabajo y la activación cerebral medida con mapeo electroencefalográfico / Influence of sex hormones in women with MS during the working memory and brain activation measured by electroencephalogram mappin

La Esclerosis Múltiple es una enfermedad inflamatoria desmielinizante del Sistema Nervioso Central, que se presenta con más frecuencia en mujeres, lo cual sugiere que las hormonas sexuales parecen modular la manifestación de la sintomatología. La actividad electroencefalografíca no ha sido evaluada en mujeres con Esclerosis Múltiple durante el procesamiento de Memoria de Trabajo y su estado hormonal. Los registros se realizaron en las fases folicular y lútea del ciclo menstrual de manera simultánea la tarea cognitiva y el electroencefalograma, además se correlacionaron con los niveles hormonales. La fase lútea mostró una ejecución mejor con un mayor número de categorías alcanzadas (p<0.004), un menor número de errores perseverativos (p<0.003) y un mayor número de ensayos para alcanzar una categoría (p<0.011), se asoció con un aumento de la actividad de Theta (p<0.018) y Alfa 2 (p<0.000). El 92 por ciento de la variabilidad en el número de ensayos de la tarea, fue explicada por la actividad de Theta y Alfa 2, Hormona Luteinizante y Estrona en la fase folicular, en la fase lútea el 90 por ciento de la variabilidad fue explicada por la actividad de Theta, Hormona Luteinizante, Progesterona y Estradiol. La Memoria de trabajo mejora en la fase lútea del ciclo menstrual, sugiriendo que la progesterona parece facilitar actividad de Theta.

Multiple Sclerosis is an inflammatory demyelinating CNS disease that occurs most often in women, suggesting that sex hormones appear to modulate the manifestation of symptoms. EEG activity has not been evaluated in women with MS during the processing of MT and hormonal status. The recordings were made in the follicular and luteal phases of the menstrual cycle a simultaneous cognitive task and EEG also were correlated with hormone levels. The luteal phase showed a better performance with a greater number of categories achieved (p <0.004), fewer perseverative errors (p <0.003) and greater number of trials to reach a category (p <0.011) was associated with increased theta activity (p <0.018) and Alpha 2 (p <0.000). 92 percent of the variability in the number of trials of the task was explained by the activity of Theta and Alpha 2, LH and estrone levels in the follicular phase, luteal phase, 90 percent of the variability was explained by the activity of theta, LH, progesterone and stradiol. The MT improvement in the luteal phase of the menstrual cycle, suggesting that progesterone seems to facilitate Theta activity.

Estrous cycle and stress: influence of progesterone on the female brain

The female brain operates in a constantly changing chemical milieu caused by cyclical changes in gonadal hormones during the estrous cycle (menstrual cycle in women). Such hormones are highly lipophilic and pass readily from the plasma to the brain where they can influence neuronal function. It is becoming clear that the rapid reduction in peripheral circulating progesterone, which occurs during the late diestrous phase of the cycle, can trigger a withdrawal-like response, in which changes in GABA A receptor expression render hyper-responsive certain brain areas involved in processing responses to stressful stimuli. The periaqueductal gray matter (PAG) is recognised as an important region for integrating anxiety/defence responses. Withdrawal from progesterone, via actions of its neuroactive metabolite allopregnanolone, triggers up-regulation of extrasynaptic GABA A receptors on GABAergic neurons in the PAG. As a consequence, ongoing GABAergic tone on the output cells decreases, leading to an increase in functional excitability of the circuitry and enhanced responsiveness to stressful stimuli during the late diestrous phase. These changes during late diestrus could be prevented by short-term neurosteroid administration, timed to produce a more gradual fall in the peripheral concentration of allopregnanolone than the rapid decrease that occurs naturally, thus removing the trigger for the central withdrawal response.

Localización extra nuclear de receptores esteroides y activación de mecanismos no genómicos / Extra nuclear localization of steroid receptors and non genomic activation mechanisms

Los receptores de hormonas esteroides han sido considerados históricamente como factores de transcripción nucleares. Sin embargo, en los últimos años surgieron evidencias que indican que su activación desencadena eventos rápidos, independientes de la transcripción y que involucran a diferentes segundos mensajeros; muchos de estos receptores han sido localizados en la membrana celular. Por otra parte, se han caracterizado varios receptores de hormonas esteroides noveles, de estructura molecular diferente al receptor clásico, localizados principalmente en la membrana celular. Esta revisión enfoca los diferentes efectos iniciados por los glucocorticoides, mineralocorticoides, andrógenos, estrógenos y progesterona, y los posibles receptores involucrados en los mismos.

Steroid hormone receptors have been historically considered as nuclear transcription factors. Nevertheless, in the last years, many of them have been detected in the cellular membrane. It has been postulated that their activation can induce transcription independent rapid events involving different second messengers. In addition, several novel steroid hormone receptors, showing a different molecular structure than the classical ones, have also been characterized and most of them are also located in the plasmatic membrane. This review focuses on the variety of effects initiated by glucocorticoids, mineralocorticoids, androgens, estrogens and progesterone, and the possible receptors involved mediating these effects.

Histomorphometrical study of the cervix during the oestrous cycle in adult Azarbaijan buffalo

In this study, genital tracts of 20 healthy non-pregnant buffaloes were collected from Urmia abattoir. These genital tracts were selected based on their ovaries conditions, half of them were in follicular phase and the other half were in luteal phase. The samples were taken from anterior, middle and posterior regions of the cervix and fixed in 10% buffer formalin. Then, histological sections of 5-7 micro m thickness were prepared and stained with haematoxylin and eosin for histomorphometrical study and toluidine blue for study of mast cells. Histomorphometrical study was accomplished by graded and latticed objective lens device. The results revealed that the thickness of epithelium significantly [P < 0.05] increased in the luteal phase. Mean thickness of mucosa-submucosa layers in the middle [290.4 +/- 12.69 micro m] and posterior [283.14 +/- 16.49 micro m] regions of the cervix in the follicular phase was significantly more than the luteal phase [P<0.05]. Mean thickness of tunica muscularis increased significantly [P<0.05] during the follicular phase in the anterior region of the cervix [3325.28 +/- 286.69 micro m]. This study also revealed that the mean distribution of mast cells in the luteal phase [0.53 +/- 0.02] was significantly more than the follicular phase [P < 0.001]. Generally, this study showed that the histomorphometrical changes in the cervix of buffalo occur in the follicular and luteal phases of oestrous cycle. These changes may be related to the fluctuation of oestrogen and progesterone hormones and distribution of mast cells

Efeitos do flunixin meglumine sobre parâmetros reprodutivos de vacas submetidas à inseminação artificial. ii- mecanismos da luteólise. revisão de literatura / Efectos del flunixin meglumine sobre parámetros reproductivos en vacas sometidas a la inseminación artificial. ii- mecanismos de luteólisis. revisión de literatura / The effects of flunixin meglumine on the reproductive parameters of artificial inseminated cows. ii- mechanisms of luteolysis: literature review

O principal papel do corpo lúteo (CL) é a produção de progesterona e uma adequada função luteal é crucial para determinar a duração do ciclo estral ou a manutenção e sucesso de uma possível gestação. A regressão do CL se dá em poucos dias, através de um processo chamado luteólise, que é desencadeado pela secreção de prostaglandina F2alfa (PGF2α). O conhecimento dos fatores ligados ao processo de regulação do corpo lúteo é importante para a manipulação do ciclo estral, na tentativa de aumentar a eficiência reprodutiva dos animais domésticos. Dentro desse contexto, este trabalho apresenta mecanismos relacionados à luteólise, que envolvem hipóteses sobre o fluxo sanguíneo uterino e ovariano, além do processo de morte celular por apoptose. Com o objetivo de se inibir a luteólise em ruminantes, avaliaram-se os efeitos do flunixin meglumine (FM) sobre a concentração sérica de progesterona, a taxa de gestação e a condição ovariana de vacas. Para tanto, 57 vacas foram divididas em grupos controle (GC n = 30) e tratado (GT n = 27), e submetidas à sincronização de estros (benzoato de estradiol IM e implante intravaginal de progesterona). Após sete dias, aplicou-se PGF2alfa IM, retirou-se o dispositivo intravaginal, e passadas 24h aplicou-se BE IM, sendo a IATF realizada 30h dessa aplicação. Os animais do GT foram submetidos diariamente a 1,1mg/kg de FM entre o 11º e 16º dia do ciclo estral (dia zero = IATF), enquanto os do GC receberam solução fisiológica. Amostras de sangue foram coletadas de todos os animais nos dias zero, seis, nove, 11 a 18 e 21, e 30 animais da raça nelore foram selecionados para dosagem sérica de progesterona por RIA. Os animais que retornaram ao estro foram re-inseminados e inseridos em seus grupos de origem. O diagnóstico de gestação foi realizado por ultrassom transretal 30 dias após a IATF ou IA, quando também se avaliou a condição ovariana nos animais não gestantes, que foi repetida quatro dias após...

The main role of the corpus luteum (CL) is progesterone production and adequate luteal function is crucial to determine the duration or continuation of the oestrous cycle and success of a possible pregnancy. The regression of the CL occurs in a few days in the process called luteolysis, triggered by the secretion of prostaglandin F2alfa (PGF2 α). Know-how of factors associated with the process of corpus luteum regulating is important for the reproductive cycle manipulation in an attempt to increase the reproductive efficiency of livestock animals. This review brings information about the mechanisms of luteolysis, which involve assumptions on the uterine and luteal blood flow and the process of cell death by apoptosis. Flunixin meglumine (FM) has been used in an attempt to inhibit luteolysis in ruminants. Towards this aim, the effects of FM were assessed on the serum concentration of progesterone, the pregnancy rate and the ovarian condition of cows. Thus, 57 cows were divided into control group (CG - n = 30) and treated group (TG - n = 27) and submitted to estrus synchronization (estradiol benzoate IM and intravaginal progesterone-releasing insert). After seven days, PGF2α IM was administered, the intravaginal device was removed, and after 24h, BE IM was administered. FTAI was performed 30h after administration. Animals from the TG were daily submitted to 1.1 mg/kg of FM between the 11th and 16th days of the estral cycle (day zero = FTAI), whereas the animals from the CG received physiological solution. Blood from all animals was collected on days zero, six, nine, eleven through eighteen and twenty-one. Thirty animals from Nelore breed were selected for seric progesterone dosage by RIA. Animals which returned to the estrus were re-inseminated and inserted into their primary groups. Pregnancy diagnosis was carried out by transretal ultrasound 30 days after either FTAI or AI....

El principal papel del cuerpo lúteo (CL) es la producción de progesterona y una adecuada función luteal es crucial para determinar la duración del ciclo estral o el mantenimiento y el éxito de una posible gestación. La regresión del CL ocurre en pocos días, a través de un proceso llamado luteólisis, que es desencadenado por la secreción de prostaglandina F2alfa (PGF2α). El conocimiento de los factores relacionados al proceso de regulación del cuerpo lúteo es importante para la manipulación del ciclo estral, con la intención de aumentar la eficacia reproductiva de los animales domésticos. En este contexto, este trabajo presenta mecanismos relacionados a la luteólisis, que envuelven hipótesis sobre el flujo sanguíneo uterino y ovárico, además del proceso de muerte celular por apoptosis. Con el objetivo de inhibirse la luteólisis en rumiantes, se evaluaron los efectos del flunixin meglumine(FM) sobre la concentración sérica de progesterona, la tasa de preñez y la condición ovárica de las vacas. Para esto, 57 vacas fueron divididas en grupos control (GC n =30) y tratado (GT n = 27) y sometidas a la sincronización de estros (benzoato de estradiol IM e implante intravaginal de progesterona). Después de siete días, se aplicó PGF2 alfa IM, se retiró el dispositivo intravaginal, y pasadas 24h se aplicó BE IM, siendo la IATF realizada 30h después de esta aplicación. Los animales del GT fueron sometidos diariamente a 1.1mg/kg de FM entre el 11º y 16º día del ciclo estral (día cero = IATF), mientras los del GC recibieron solución fisiológica. Muestras de sangre fueron colectadas de todos los animales en los días cero, seis, nueve, 11 a 18 y 21, y 30 animales de la raza nelore fueron seleccionados para el análisis sérico de progesterona por RIA. Los animales que retornaron al estro fueron reinseminados e inseridos en sus grupos de origen. El diagnóstico de preñez fue realizado por ecografía transrectal 30 días después a la IATF o IA,...

Papel inmunológico de la progesterona en el mantenimiento del embarazo / Immunological role of progesterone in the maintenance of pregnancy

Progesterone is an essential hormone for pregnancy maintenance. This hormone acts by binding to its intracellular receptor or by rapid non-genomic actions to regulate a wide variety of biological functions in the feto-placental unit. Progesterone regulates blastocyst implantation and placental development by inducing immunosupression through type Th2 cytokines secretion. This review summarizes current research about the role of progesterone as critical regulator of expression and secretion of cytokines by T-cell and other placental cells.

La progesterona es una hormona esteroide muy versátil y esencial para el mantenimiento del embarazo. El principal mecanismo de acción de la progesterona es el clásico, vía receptor intracelular, regulando diversas funciones, aspectos celulares y vías moleculares implicadas en el proceso de la implantación. Asimismo existen mecanismos adicionales que no dependen de la interacción del complejo hormona receptor con la maquinaria transcripcional y que son capaces de regular rápidamente cascadas de señalización que determinarán la respuesta de la célula. En particular se ha demostrado que la progesterona ejerce efectos inmunosupresores durante la gestación al favorecer la secreción de citocinas de tipo Th2 por los linfocitos T, evento importante para regular el sistema inmunológico materno y evitar el rechazo de la placenta. El objetivo de esta revisión se centra en analizar la influencia de la progesterona en la interfase materno-fetal sobre la expresión y secreción de citocinas por las células T y no T como es el caso del trofoblasto.

Mecanismos endócrinos e moleculares envolvidos na formação do corpo lúteo e na luteólise - revisão de literatura / Endocrine and molecular mechanisms involved in the formation of corpus luteum and luteolysis - A Review

O corpo lúteo (CL) é uma estrutura endócrina transitória formada por células luteais esteroidogênicas pequenas (SLC) e grandes (LLC), que associadas aos fibroblastos e a uma ampla rede de capilares constituem uma estrutura especializada na síntese de progesterona (P4). De maneira geral, para a síntese de P4 nas células luteais esteroidogênicas, o colesterol se liga a receptores específicos na membrana celular e é transportado ao citosol. Posteriormente, o colesterol dirige-se a membrana mitocondrial interna e por ação da enzima P450scc transforma-se em pregnenolona. No retículo endoplasmático liso a pregnenolona é convertida a P4 pela enzima 3β-hidroxiesteróide deidrogenase (3β-HSD). A proteína de regulação aguda da esteroidogênese (StAR), o receptor benzodiazepínico tipo periférico (PBR) e a endozepina participam no transporte do colesterol para os diferentes compartimentos mitocondriais. Assim, supõe-se que a capacidade de síntese de P4 no CL esteja relacionada à concentração celular de receptores que captam o colesterol, às enzimas P450scc e 3β-HSD, e às proteínas celulares transportadoras de colesterol. Na espécie bovina, as LLC são responsáveis por mais de 80% da produção deste hormônio no CL. A menor concentração de proteínas transportadoras de colesterol na mitocôndria parecem limitar a síntese de P4 nas SLC. A P4 favorece um meio ambiente uterino apropriado para o desenvolvimento do(s) concepto(s), dependendo da espécie. Na maioria das espécies, a ausência da fertilização ou a incapacidade do concepto em sinalizar sua existência no útero estabelecem a luteólise. Tal evento fisiológico caracteriza-se pela regressão funcional e estrutural do(s) corpo(s) lúteo(s). Para o estabelecimento e a manutenção da prenhez torna-se necessário o bloqueio da luteólise por mecanismos que diferem entre as espécies. Em primatas e equídeos esse reconhecimento ocorre pela secreção de gonadotrofinas específicas e em ruminantes pela presença de fatores ...

The corpus luteum (CL) is a transitory endocrinal structure formed by steroidogenic small luteal cells (SLC) and large luteal cells (LLC) that associated with fibroblast and a wide web of capillaries form a structure specialized in synthesis of progesterone (P4) In general, for the synthesis of P4 in the steroidogenic luteal cells, cholesterol joints specific receptors on the cellular membrane and is transported to the cytosol. Later, cholesterol goes to an internal mitochondrial membrane and by the action of the enzyme P450scc is transformed into pregnenolone. In the smooth endoplasmic reticulum pregnenolone is converted to P4 by the enzyme 3β-hydroxysteroid dehydrogenase (3 β -HSD). The steroidogenic acute regulatory protein (StAR), the peripheral benzodiazepine receptor (PBR) and endozepine participate in the transport of cholesterol to the different mitochondrial compartments. Therefore, it is supposed that the capacity of synthesis of P4 in the CL is related to the cellular concentration of receptors that catch cholesterol, to the enzymes P450scc and 3β-HSD and to the cholesterol cellular transport proteins. In bovine, the LLC are responsible for more than 80 of P4 production in the CL. The lowest concentration of cholesterol transport proteins in the mitochondria seems to limit the synthesis of P4 in the SLC. P4 supports a proper uterine environment for the development of conceptuses, depending on the specie. In most species, the lack of fertilization or the conceptus incapacity to signalize its presence in the uterus establishes luteolysis. This physiolocal event is characterized by the functional and structural regression of the CL. For the establishment and maintenance of pregnancy it is necessary to block luteolysis through different mechanisms among species. In primates and equids it occurs by the secretion of specific gonadotropins and in ruminants by antiluteolytic factors. This review has the objective to characterize the endocrine ...

Ação do estrógeno e progesterona na mucosa nasal humana: avaliação do transporte mucociliar nasal de sacarina e pesquisa de receptores hormonais através de método imuno-histoquímico / Estrogen and progesterone influence in human nasal mucosa: evaluation of nasal saccharin mucociliary transport and test for hormone receptors with immunohistochemical staining

Apesar do estudo exaustivo do transporte mucociliar nasal, ainda há dados controversos sobre a influência direta dos hormônios sexuais femininos nesse mecanismo. O presente estudo teve por objetivos: 1. avaliar o transporte mucociliar nasal de sacarina nos sexos masculino e feminino, comparando-o nas fases folicular, periovulatória e lútea de ciclos ovarianos consecutivos e 2. identificar a expressão e a localização dos receptores para estrógeno e progesterona na mucosa nasal humana em conchas nasais inferiores de indivíduos dos sexos masculino e feminino na idade reprodutiva. O transporte mucociliar nasal de sacarina foi avaliado prospectivamente em 14 voluntários não fumantes, sem queixas nasais, com idades entre 15 e 30 anos (7 homens e 7 mulheres, com média de idade 23,5 anos). Nas mulheres, o transporte mucociliar nasal de sacarina foi medido nas fases folicular, periovulatória e lútea durante dois ciclos ovarianos consecutivos (em cinco casos) ou três ciclos consecutivos (em dois casos). Nos homens, o transporte mucociliar nasal de sacarina foi avaliado em medidas repetidas aleatoriamente três vezes (em dois casos) ou seis vezes (em cinco casos). A expressão dos receptores para estrógeno e progesterona na mucosa nasal humana foi avaliada por método imunohistoquímico, de modo retrospectivo, em conchas nasais inferiores conservadas em formaldeído e fixadas na parafina, arquivadas após a cirurgia de turbinectomia parcial da concha inferior a que foram submetidos 20 pacientes da mesma faixa etária dos voluntários (10 pacientes do sexo masculino e 10 do sexo feminino, com idades entre 15 e 33 anos, média de idade 22,1 anos). Para a imuno-histoquímica utilizaram-se anticorpos monoclonais de camundongo contra receptores para estrógeno (clone 6F11, Novocastra) e para progesterona (clone 16, Novocastra) separadamente. Não houve diferenças significativas no transporte mucociliar nasal de sacarina entre as fases folicular...

Although nasal mucociliary clearance has been thoroughly studied, there is controversial evidence that it is directly influenced by female sex hormones. This study focused on: 1. evaluating saccharin nasal mucociliary transport in both sexes and during the follicular, periovulatory and luteal phases of consecutive ovarian cycles, and 2. identifying the expression and localisation of estrogen and progesterone receptors in human nasal mucosa from inferior turbinates of patients in reproductive age. Saccharin nasal mucociliary transport was prospectively evaluated in 14 nonsmoking healthy volunteers aged 15 to 30 years (7 males and 7 females, mean age 23.5 years) who had no nasal complaints. In females, saccharin nasal mucociliary transport was measured in the follicular, periovulatory and luteal phases during two consecutive ovarian cycles (five cases) or three consecutive cycles (two cases). In males, the saccharin nasal mucociliary transport was randomly repeated three times (two cases) or six times (five cases). Estrogen and progesterone receptor expression in human nasal mucosa was retrospectively assessed by immunohistochemistry in archival, formalin-fixed, paraffin-embedded inferior nasal conchae from 20 patients submitted to partial inferior turbinectomy whose ages were matched to their of the volunteers (10 male and 10 female patients aged 15 to 33 years, mean age 22.1 years). Immunohistochemistry used mouse monoclonal antibodies against estrogen receptor (6F11 clone, Novocastra) and progesterone receptor (16 clone, Novocastra) separately. There were no significant differences in saccharin nasal mucociliary transport among follicular, periovulatory and luteal phases in consecutive ovarian cycles, nor between sexes (p=.08). Even though, considering the first ovarian cycle only, saccharin nasal mucociliary transport was faster during the follicular phase (p=.03). Estrogen and progesterone receptors were found in the cytoplasm of serous...

Las isoformas del receptor a progesterona: función y regulación / Progesterone receptor isoforms: function and regulation

La progesterona participa en la regulación de diversos procesos fisiológicos en los mamíferos. La respuesta biológica a la progesterona está mediada por dos isoformas del receptor a progesterona (PR) denominadas PR-A y PR-B. La diferencia entre éstas está dada por 164 aminoácidos de la región amino-terminal de PR-B que están ausentes en PR-A. Ambas isoformas son codificadas por el mismo gen pero son reguladas por distintos promotores que son inducidos por los estrógenos. PR-B actúa como un fuerte activador transcripcional en diferentes contextos celulares mientras que PR-A funciona como un inhibidor. El contenido de las isoformas del PR, así como su regulación por hormonas esteroides se presenta de manera tejido-específica en los órganos blanco como el útero, la glándula mamaria y el cerebro. El conocimiento de los mecanismos moleculares por los cuales se regula la expresión y función de las isoformas del PR permitirá entender procesos biológicos fundamentales como la conducta sexual y la reproducción; además contribuirá al diseño de terapias hormonales en el control de la fertilidad, así como en el tratamiento de tumores de mama, endometriales y cerebrales.

Effect of medroxyprogesterone acetate on thyrotropin secretion in adult and old female rats

Steroid hormones have been implicated in the modulation of TSH secretion; however, there are few and controversial data regarding the effect of progesterone (Pg) on TSH secretion. Medroxyprogesterone acetate (MPA) is a synthetic alpha-hydroxyprogesterone analog that has been extensively employed in therapeutics for its Pg-like actions, but that also has some glucocorticoid and androgen activity. Both hormones have been shown to interfere with TSH secretion. The objective of the present study was to investigate the effects of MPA or Pg administration to ovariectomized (OVX) rats on in vivo and in vitro TSH release and pituitary TSH content. The treatment of adult OVX rats with MPA (0.25 mg/100 g body weight, sc, daily for 9 days) induced a significant (P<0.05) increase in the pituitary TSH content, which was not observed when the same treatment was used with a 10 times higher MPA dose or with Pg doses similar to those of MPA. Serum TSH was similar for all groups. MPA administered to OVX rats at the lower dose also had a stimulatory effect on the in vitro basal and TRH-induced TSH release. The in vitro basal and TRH-stimulated TSH release was not significantly affected by Pg treatment. Conversely, MPA had no effect on old OVX rats. However, in these old rats, ovariectomy alone significantly reduced (P<0.05) basal and TRH-stimulated TSH release in vitro, as well as pituitary TSH content. The results suggest that in adult, but not in old OVX rats, MPA but not Pg has a stimulatory effect on TSH stores and on the response to TRH in vitro

Role of estradiol in the capacitation and acrosome reaction of hamster epididymal spermatozoa in the isolated uterus of mice incubated in vitro.

The site of sperm capacitation, the agents and mechanisms causing capacitation and acrosome reaction (AR) in vivo are not well understood. The female reproductive tract has been reported to play a key role during capacitation and AR. Some experiments were carried out on the capacitation and AR of hamster epididymal spermatozoa in the estrogen and progesterone dominated uterus (estrous and diestrous respectively) albino mice, incubated in TALP without calcium and BSA. Also the effect of estradiol (200 micrograms/ml) supplemented to TALP, on capacitation and AR was examined. Capacitation and AR of hamster spermatozoa incubated in the isolated uterus of both estrous and diestrous mice were significantly (P < 0.05) higher in the presence of exogenous estradiol than that in its absence. Acrosome shedding occurred earlier i.e. at 3rd hour as compared to the in vitro studies where it occurred at 5th hour. The present study thus reveals that uterus of both estrogen and progesterone dominated mice play an important role in the induction of capacitation and AR. The addition of estradiol might have the influence on the synthesis of uterine proteins of mice which might be important for capacitation and AR.

Lactogênese e reflexo ejecto-láctil / Lactogenesis and milk-ejection reflex

Apresenta-se uma revisäo näo exaustiva sobre os processos fisiológicos envolvidos com a produçäo e a ejeçäo de leite, bem como fatores que interferem em tais processos.

Progesterone decreases calving interval. a preliminary study

This experimental study on 18 cows was carried from February to June, 1995. Progesterone was administered [25 mg] to each cow on alternate days for 11 days and this oestrus symptoms were observed from day 12 to 14. Sixteen [88.9%] animals showed oestrus through physical symptoms and the oestrus of 15 [83.3%] animals were diagnosed with milk progesterone level [<2ng/ml]. Natural breeding was only allowed to animals at proper oestrus. On 22nd day of insemination, milk progesterone >7ng/ml was found in 13 [72.2%] animals while rectal examination on day 60 of breeding showed 12 [66.7%] animals to be pregnant. However, both methods demonstrated that progesterone decreases calving interval by exhibiting early oestrus

Climaterio y depresión / Climaterium and depression

Este artículo es una revisión resumida de la bibliografía en torno a la depresión en el climaterio. El climaterio se considera como la fase de transición entre la etapa reproduciva y la no reproductiva de la mujer, la cual se presenta, aproximadamente, a partir de los 35 años de edad. El climaterio se caracteriza por síntomas vasomotores (bochornos) y por síntomas psicológicos (depresión), entre otros. Esta sintomatología se deriva de dos componentes principales: la disminución de estrógenos y los factores psico-socio-culturales. A pesar de que se han considerado otras hormonas como la TSH, la prolactina, la LH, la FSH y la GnRH, la hormona que tiene más peso como factor etiológico es el estrógeno. Este estudio está enfocado a los estrógenos y a su fisiología en la conducta, a su mecanismo de acción y a su relación con las beta-endorfinas. También trata brevemente de la progesterona, la FH, la LH, la GnRH, la TSH, la TRH y la prolactina. Se encontró que la fisiopatología de la depresión en la mujer climatérica se debe, principalmente a la deficiencia estrogénica, y que los estrógenos no sólo son la etiología de la depresión en el climaterio, sino que también participan en la depresión que ocurre en muchas otras etapas reproductivas y no reproductivas de la mujer (i.e menstruación, postparto, histerectomía con ooforectomía bilateral, etc.), lo que sugiere que el cuadro depresivo que se presenta durante el climaterio podría deberse a las fluctuaciones de los niveles séricos de los estrógenos

Efecto de la adición de progesterona al semen de verraco antes de la congelación o después de la descongelación sobre la fertilidad, morfología acrosomal y motilidad de los espermatozoides / Progesterone addition to boar semen before freezing or after thawing. Effects on fertility acrosomal morphology and sperm motility

Se utilizaron 39 cerdas primerizas híbridas y un verraco de raza landrace. Las cerdas fueron asignadas al azar para los siguientes tratamientos: en el grupo 1 (n 13) las hembras recibieron dos inseminaciones con semen congelado, a éste se le añadieron 5 mg de progesterona antes de su congelación; en el grupo 2 (n 13) se inseminaron dos veces con semen, al que se le añadieron 5 mg de progesterona después de descongelar; el grupo 3 que actuó como testigo (n 13) recibió dos inseminaciones con semen congelado sin progesterona. Cada eyaculado se dividió en tres porciones, de acuerdo con los tratamientos. Las cercad fueron enviadas al rastro 35 días postservicio para determinar el número de cuerpos lúteos y embriones presentes. También se evaluaron la morfología acrosomal y la motilidad de los espermatozoides, antes y después de la congelación. El porcentaje de gestación fue de 53.8, 46.1 y 61.5 en los grupos 1, 2 y 3, respectivamante (P > 0.05). Los porcentajes de espermatozoides con acrosoma normal al descongelar fueron 50.5, 49.7 y 46.8 para los mismos grupos (P > 0.05). La motilidad del semen descongelado e incubado a 37ºC/30 min fue de 45.4, 40.6 y 40.2, respectivamante (P > 0.05). La progesterona añadida al semen, antes o después de la congelación, no tiene influencia en la fertilidad ni tampoco sobre la morfología y mortalidad de los espermatozoides del verraco

La piel durante el embarazo / Skin in pregnancy

La embarazada experimenta en su piel, durante los 280 días que dura su estado de gravidez, una serie de cambios muy notorios, que por su alta incidencia se consideran normales. En este trabajo se hace un análisis de los cambios fisiológicos que se presentan en los tegumentos durante la gestación; se revisan somerante las alteraciones endocrinológicas y se describen los padecimientos y lesiones dermatológicas que se observan en las embarazadas, exceptuando las erupciones pruriginosas específicas del embarazo