RESUMO
Reproduction in all mammalian species depends on the growth and maturation of ovarian follicles, that is, folliculogenesis. Follicular development can culminate with the rupture of mature follicles and the consequent expulsion of their oocytes (ovulation) or in atresia, characterized by the arrest of development and eventual degeneration. These processes are regulated by different neuroendocrine signals arising at different hypothalamic nuclei, including the suprachiasmatic nucleus (SCN). In the later, the activation of muscarinic receptors (mAChRs) and nicotinic receptors (nAChRs) by acetylcholine is essential for the regulation of the pre-ovulatory signals that stimulate the rupture of mature follicles. To evaluate the participation of the nAChRs in the SCN throughout the oestrous cycle in the regulation of the hypothalamic-pituitary-ovarian axis. For this purpose, 90-day-old adult female rats in metoestrus, dioestrus, proestrus or oestrus were microinjected into the left- or right-SCN with 0.3 µL of saline solution as vehicle or with 0.225 µg of mecamylamine (Mec), a non-selective antagonist of the nicotinic receptors, diluted in 0.3 µL of vehicle. The animals were sacrificed when they presented vaginal cornification, indicative of oestrus stage, and the effects of the unilateral pharmacological blockade of the nAChRs in the SCN on follicular development, ovulation and secretion of oestradiol and follicle-stimulating hormone (FSH) were evaluated. The microinjection of Mec decreased the serum levels of FSH, which resulted in a lower number of growing and healthy follicles and an increase in atresia. The higher percentage of atresia in pre-ovulatory follicles was related to a decrease in the number of ova shed and abnormalities in oestradiol secretion. We also detected asymmetric responses between the left and right treatments that depended on the stage of the oestrous cycle. The present results allow us to suggest that during all the stages of the oestrous cycle, cholinergic signals that act on the nAChRs in the SCN are pivotal to modulate the secretion of gonadotropins and hence the physiology of the ovaries. Further research is needed to determine if such signals are generated by the cholinergic neurons in the SCN or by cholinergic afferents to the SCN.
RESUMO
In rats with polycystic ovary syndrome (PCOS) induced by injection of estradiol valerate (EV), unilateral or bilateral section of the vagus nerve restores ovulatory function in 75% of animals, suggesting that the vagus nerve participates in the development of PCOS. Since the vagus nerve is a mixed nerve through which mainly cholinergic-type information passes, the objective of the present study was to analyze whether acetylcholine (ACh) is involved in the development of PCOS. Ten-day-old rats were injected with 2.0 mg EV, and at 60 days of age, they were microinjected on the day of diestrus in the bursa of the left or right ovary with 100 or 700 mg/kg of ovarian weight atropine, a blocker of muscarinic receptors, and sacrificed for histopathological examination after the surgery. Animals with PCOS microinjected with 100 mg of atropine showed a lack of ovulation, lower serum concentrations of progesterone and testosterone, and cysts. Histology of the ovaries of animals microinjected with 700 mg of atropine showed corpus luteum and follicles at different stages of development, which was accompanied by a lower concentration of progesterone and testosterone. These results allow us to suggest that in animals with PCOS, ACh, which passes through parasympathetic innervation, is an important component in the persistence and development of the pathophysiology.
Assuntos
Síndrome do Ovário Policístico , Progesterona , Animais , Atropina/farmacologia , Estradiol , Feminino , Ovulação/efeitos dos fármacos , RatosRESUMO
Objetivo. Realizar una revisión de la literatura sobre rehabilitación en niños en tiempos de la pandemia por Covid-19, sintetizando las recomendaciones expuestas por los documentos de consenso internacional y la bibliografía reciente. Además, exponer la manera como estas recomendaciones se puedan aplicar bajo la forma de un protocolo multidisciplinar desde la tele-rehabilitación. Materiales y métodos. Se realizó una búsqueda bibliográfica de la literatura existente y de los consensos internacionales centrados en el diagnóstico, la presentación clínica y la rehabilitación en niños durante la pandemia por Covid-19, desde el 01 de enero de 2020 al 31 de mayo del 2020, en las bases de datos e Pubmed, Science Direct, Clinical Key, Embase y Ovid. Con base en estas recomendaciones se ofrecen pautas para ser implementadas en la modalidad de telerehabilitación en niños. Resultados. Se encontró un total de 471 artículos de los cuales 34 cumplieron con los criterios de inclusión. Conclusiones. La rehabilitación infantil plantea el objetivo de disminuir la limitación de la actividad y mejorar la participación en todos los entornos. A casusa de la pandemia actual, la necesidad de confinamiento ha llevado a que buena parte de la rehabilitación se implemente en casa, mediante ayudas tecnológicas conocidas como 'tele-rehabilitación'. No hay que olvidar que esta modalidad de tratamiento debe ser interdisciplinar y enfocada en la prevención de problemas a mediano y largo plazo. El impacto del Covid-19 aún es incierto y la rehabilitación no debe parar, pues el objetivo es brindar herramientas para conseguir la máxima funcionalidad de todos los niño
Objective. To review the literature on rehabilitation in children in times of the Covid-19 pandemic, synthesizing the recommendations set forth in international consensus documents and recent literature. In addition, to show how these recommendations can be applied in the form of a multidisciplinary protocol from tele-rehabilitation. Materials and methods. A bibliographic search of the existing literature and international consensus focused on diagnosis, clinical presentation and rehabilitation in children during the Covid-19 pandemic, from January 1, 2020 to May 31, 2020, was performed in Pubmed, Science Direct, Clinical Key, Embase and Ovid databases. Based on these recommendations, guidelines are offered to be implemented in the telerehabilitation modality in children. Results. A total of 471 articles were found, of which 34 met the inclusion criteria. Conclusions. Children's rehabilitation aims to reduce activity limitation and improve participation in all environments. Because of the current pandemic, the need for confinement has led to a large part of rehabilitation being implemented at home, by means of technological aids known as 'tele-rehabilitation'. It should not be forgotten that this treatment modality should be interdisciplinary and focused on the prevention of medium and long-term problems. The impact of Covid-19 is still uncertain and rehabilitation must not stop, since the objective is to provide tools to achieve maximum functionality for all children.