RESUMEN
Although it has been known for many years that the ovary is innervated by catecholaminergic nerve fibers and much experimental evidence has strengthened the notion that catecholamines are physiologically involved in the control of ovarian function, scarce evidence has been presented as to the role of sympathetic activity in ovarian pathologies that affect reproductive function. The purpose of this article is to provide a succinct overview of the findings in this area and discuss them relative to the pathology of polycystic ovary syndrome, the most common ovarian pathology in women during their reproductive years.
Asunto(s)
Ciclo Estral/fisiología , Norepinefrina/metabolismo , Ovario/inervación , Síndrome del Ovario Poliquístico/metabolismo , Sistema Nervioso Simpático/fisiopatología , Animales , Estradiol/análogos & derivados , Estradiol/metabolismo , Femenino , Humanos , Ovario/metabolismo , Síndrome del Ovario Poliquístico/patologíaRESUMEN
The subcommissural organ (SCO) is a brain gland secreting glycoproteins into the cerebrospinal fluid (CSF), where they aggregate forming the Reissner's fiber (RF). By the continuous addition of newly released glycoproteins, RF grows along the cerebral aqueduct, fourth ventricle, and central canal of the spinal cord. At the filum, RF-glycoproteins escape from the central canal and reach the local blood vessels. Despite a century of research, the function of the SCO remains elusive. The aim of the present investigation was to test the hypothesis that RF-glycoproteins, by binding and transporting monoamines out of the CSF, participate in the clearance of these compounds. A protocol was designed that led to the permanent immunoneutralization of the SCO through the maternal delivery of antibodies. This was achieved by transplacental transfer to the fetuses, and through the milk to the pups, of specific antibodies against SCO secretory proteins. The antibodies reached the CSF of the fetuses and pups and blocked the RF formation during the first months of life. Some of these animals died during the first postnatal weeks; those who survived displayed a rise in the CSF concentration of several monoamines, l-DOPA being the one with the highest rise. Adult rats transiently deprived of RF by a single injection of anti-RF antibodies into the CSF showed a transient rise in the CSF concentration of l-DOPA. All these results support the hypotheses that the SCO-RF complex participates in the clearance of monoamines from the CSF.
Asunto(s)
Anticuerpos Antiidiotipos/inmunología , Monoaminas Biogénicas/líquido cefalorraquídeo , Glicoproteínas/fisiología , Inmunidad Materno-Adquirida/fisiología , Inmunoglobulina G/inmunología , Órgano Subcomisural/fisiología , Animales , Animales Recién Nacidos , Anticuerpos Antiidiotipos/administración & dosificación , Anticuerpos Antiidiotipos/líquido cefalorraquídeo , Femenino , Feto , Glicoproteínas/sangre , Glicoproteínas/inmunología , Inmunoglobulina G/administración & dosificación , Inmunoglobulina G/líquido cefalorraquídeo , Inmunoglobulina G/farmacología , Levodopa/líquido cefalorraquídeo , Leche/inmunología , Embarazo , Ratas , Ratas Sprague-Dawley , Órgano Subcomisural/inmunologíaRESUMEN
BACKGROUND AND AIMS OF THE STUDY: This study was performed to identify the physical and histopathologic characteristics of different sections of glutaraldehyde-tanned bovine pericardium. METHODS: Ten pericardial sacs were obtained from animals aged from 18 to 36 months. Physical tests included shrinkage and mechanical resistance (rupture, elongation, tenacity index). Collagen and elastic fibers were evaluated in Gomori's trichrome-stained sections, hematoxylin and eosin, by PAS and Verhoeff's method. Studied areas were proximal to the great arteries, and the right atrial, right ventricular, left ventricular and left atrial regions. RESULTS AND CONCLUSIONS: Results showed that bovine pericardium does not have enough regional differences to identify any single region for bioprosthesis manufacture. However, histopathology showed better preservation of collagen and elastic fibers in the right ventricular region, implying that this area is more adequate as bioprosthetic material.
Asunto(s)
Materiales Biocompatibles , Bioprótesis , Pericardio/patología , Conservación de Tejido/métodos , Animales , Bovinos , Colágeno/análisis , Técnicas de Cultivo , Elasticidad , Glutaral , Ensayo de Materiales , Pericardio/química , Pericardio/fisiopatología , Estrés Mecánico , Resistencia a la Tracción , Obtención de Tejidos y Órganos/métodosRESUMEN
This work describes the results of the controlled crosslinking of collagen matrices by glutaraldehyde based on a double protection strategy, glutaraldehyde acetals and lysine protonation due to the acidic conditions of acetal formation. Materials crosslinked by this approach were characterized by thermal stability comparable to those obtained by conventional procedures with mechanical properties expected for bioprosthesis manufacture and with a higher stability toward collagenase hydrolysis. The integrity of the microfibrillar structure was confirmed by optical and scanning electronic microscopy. The results indicate that the glutaraldehyde acetals procedure may be of potential use for the crosslinking of bovine pericardium used in the manufacture of bioprosthetic devices. Advantages may be related to the production of materials with homogeneous crosslinking distributions, associated with better definition in the nature of the chemical link that they introduce, due to a better distribution of glutaraldehyde within the tissue matrix before the crosslinking reaction is allowed to occur. As a result, materials with improved biological and mechanical properties are expected.
Asunto(s)
Acetales/química , Colágeno/química , Reactivos de Enlaces Cruzados/química , Glutaral/química , Pericardio/química , Animales , Fenómenos Biomecánicos , Bioprótesis , Rastreo Diferencial de Calorimetría , Bovinos , Lisina/química , Pericardio/ultraestructura , Espectrofotometría UltravioletaRESUMEN
The activity of the gonadotropin-releasing hormone (GnRH) pulse generator during lactation was assessed by direct determination of GnRH levels impinging upon the pituitary gland. Sprague-Dawley rats were implanted on day 15 of pregnancy with a push-pull perfusion cannula directed to the anterior pituitary. All implanted animals showed normal parturition, maternal behavior and lactation. Push-pull perfusions were performed in 15 rats suckling 11.0 +/- 0.8 pups (range 4-15) on day 7-20 of lactation and repeated on diestrous 1 after weaning in some of the same animals. GnRH content of the samples was assayed by RIA. GnRH pulses were clearly detected during lactation. Mean GnRH secretion rate was 1.9 +/- 0.3 pg/10 min (chi +/- SE, range between 0.5 and 3 pg/10 min) and interpulse interval was 37.5 +/- 1.7 min (range between 27 and 50 min). There was a significant decrease of about 19% in the interpulse interval after weaning. There was no significant difference in GnRH pulse amplitude nor in GnRH secretion rate between lactation and diestrous. These results demonstrate that nursing does not suppress the GnRH pulse generator in the rat.
Asunto(s)
Diestro/metabolismo , Hormona Liberadora de Gonadotropina/biosíntesis , Hipotálamo/metabolismo , Lactancia/metabolismo , Hormona Luteinizante/biosíntesis , Hipófisis/metabolismo , Animales , Femenino , Perfusión , Radioinmunoensayo , Ratas , Ratas Sprague-DawleyRESUMEN
The activity of the gonadotropin-releasing hormone (GnRH) pulse generator during lactation was assessed by direct determination of GnRH levels impinging upon the pituitary gland. Sprague-Dawley rats were implanted on day 15 of pregnancy with a push-pull perfusion cannula directed to the anterior pituitary. All implanted animals showed normal parturition, maternal behavior and lactation. Push-pull perfusions were performed in 15 rats suckling 11.0 +/- 0.8 pups (range 4-15) on day 7-20 of lactation and repeated on diestrous 1 after weaning in some of the same animals. GnRH content of the samples was assayed by RIA. GnRH pulses were clearly detected during lactation. Mean GnRH secretion rate was 1.9 +/- 0.3 pg/10 min (chi +/- SE, range between 0.5 and 3 pg/10 min) and interpulse interval was 37.5 +/- 1.7 min (range between 27 and 50 min). There was a significant decrease of about 19 percent in the interpulse interval after weaning. There was no significant difference in GnRH pulse amplitude nor in GnRH secretion rate between lactation and diestrous. These results demonstrate that nursing does not suppress the GnRH pulse generator in the rat