In utero betamethasone affects 3ß-hydroxysteroid dehydrogenase and inhibin-α immunoexpression during testis development.

Prenatal glucocorticoids, commonly used in women at risk of preterm delivery, can predispose the newborn to disease in later life. Since male reproductive function is likely to reflect testis development during fetal life, we studied the effects of prenatal glucocorticoids on two key intra-testicular factors that play roles in cellular proliferation and differentiation, 3ß-hydroxysteroid dehydrogenase (3ß-HSD) and inhibin-α. Pregnant sheep (n=42) were treated with betamethasone (0.5 mg/kg) or saline (control) at 104, 111 and 118 days of gestation (DG). Testicular tissue was sampled from fetuses at 121 and 132DG, and from lambs at 45 and 90 postnatal days (PD). Within the betamethasone treated group, 3ß-HSD immunostaining area was greater at 121DG than at 90PD (P=0.04), but the intensity of immunostaining was higher at 90PD than at 121DG (P=0.04), 132DG (P=0.04) and 45PD (P=0.03). Control animals showed no changes in 3ß-HSD area or intensity of immunostaining. No significant differences were observed between treated and control animals in immunostaining area, but immunostaining was more intense in the treated group than in the control group at 90PD (P=0.03). For inhibin-α, the proportion of immunostaining area declined in treated offspring from 121DG to 45PD, in contrast to control values, but recovered fully by 90PD, concomitantly with the onset of spermatogenesis. In conclusion, prenatal betamethasone increased the postnatal testicular expression of inhibin-α but reduced the expression of 3ß-HSD. These effects could compromise androgen-mediated testicular development and therefore adult capacity for spermatogenesis.

Obtención, evaluación y congelación de semen de antilope adulto (Addax nasomaculatus) del Zoo-Parque Lecocq de Montevideo-Uruguay / Collection, evaluation and freezing of sperm antilope adult (Addax nasomaculatus) of the Lecocq Zoo-Park in Montevideo-Uruguay

La criopreservación de semen es una importante biotecnología reproductiva que viene siendo utilizada con éxito desde hace casi 50 años que busca promover la conservación del germoplasma masculino. Si bien en la actualidad se han desarrollado sistemas electrónicos automatizados portátiles, muchos técnicos continúan utilizando el método convencional de congelación por su practicidad, bajo costo y su buena eficiencia. En este trabajo, utilizando protocolos estandarizados para la evaluación reproductiva de machos de otras especies se presentan datos preliminares sobre obtención, evaluación y congelación de gameto masculino de antílopes adultos (Addax nasomaculatus). Se obtuvo el semen de tres antílopes machos adultos, registrándose volumen, color, motilidad, vigor, vitalidad, concentración y morfología. El semen fue congelado por el método convencional y preservado en nitrógeno a -196 C. Los machos respondieron satisfactoriamente al método de sedación y extracción de semen. Tanto la evaluación del semen fresco como del semen congelado mostraron datos preliminares aceptables que validan la metodología utilizada y estimulan a continuar trabajando con esta especie dada su condición de animales en cautiverio y en peligro de extinción.

For almost 50 years sperm cryopreservation has been an important reproductive biotechnology that promotes the conservation of male germplasm. While today automated portable electronic systems have been developed, many technicians continue to use the conventional method of freezing for its practicality, low cost and efficiency. In this work we present preliminary data using standard protocols for assessing reproductive males of other species, about evaluation and freezing of adult antelope (Addax nasomaculatus) male gamete. Semen from three adult male antelope was obtained; we registered volume, color, motility, vigor, vitality, concentration and morphology. The semen was frozen by the conventional method and preserved under -196 C nitrogen. Males responded satisfactorily to the method of sedation and extraction of semen. The evaluation of fresh and frozen semen showed acceptable preliminary data that validate the methodology and encourage them to continue working with this species because of their status of animals in captivity and in danger of extinction.

A quantitative study of rat uterine sympathetic innervation during pregnancy and post partum.

In mammals, pregnancy induces a transient and extensive degeneration of uterine sympathetic innervation. We used the models of unilateral oviduct ligation and in oculo myometrium transplant in pregnant rats to address the role of stretching forces and/or hormone milieu in the loss of sympathetic innervation. The sympathetic fibres of the uterine horn and in oculo myometrial transplants were quantified on tissue sections processed by the glyoxylic acid technique. In normal pregnant rats, the density of uterine horn innervation was significantly reduced at late pregnancy and recovery took place during post partum. The empty horn of pregnant rats showed no significant changes in density of myometrial innervation during pregnancy or post partum. In oculo myometrial transplants were organotypically reinnervated in virgin animals. When the transplants were exposed to gestational hormonal milieu, few or no fibres were observed to the end of pregnancy; however, a significant increase at post partum was observed. Results showed that both the effects of stretching and the hormone milieu derived from the fetus-placenta complex play a role as inductors of changes on sympathetic myometrial innervation during pregnancy and support the idea that immature muscular uterine fibres are more susceptible to the effects of pregnancy than those originating from adult animals.

Intrinsic neurons in the human ovary.

Mammalian ovarian function is regulated by both hormonal inputs and direct neural influences. Recent studies have shown that, in addition to the extrinsic innervation, the ovaries of nonhuman primates and a strain of rats contain a discrete population of intrinsic neurons. In the present study, we used histological and immunohistochemical approaches to identify the presence of neuronal cell bodies in the fetal and neonatal human ovary. Neurons containing neurofilament immunoreactivity were detected in the hilum and medulla of the ovary at all ages studied, ranging from 24 weeks of gestation to 10 months of postnatal age. Most of them coexpressed the low affinity neurotrophin receptor (p75NTR), and some were catecholaminergic, as determined by their content of immunoreactive tyrosine hydroxylase (TH), the rate-limiting enzyme in catecholamine biosynthesis. The presence of intrinsic neurons in the human ovary, similar to those previously found in other species, indicates that they may be engaged in regulating common, phylogenetically conserved, ovarian functions. It also raises the possibility that their dysfunction may contribute to the manifestation of particular ovarian pathologies.

Intrinsic neurons in the rat ovary: an immunohistochemical study.

Previous studies have shown the presence of neuronal perikarya in the primate ovary, but not in the ovary from Sprague-Dawley rats. We report here that while such intrinsic neurons are indeed absent in this strain of rats, they can be visualized in the ovary from Wistar rats. The neurons, identified by their morphology and by the expression of NeuN (a neuron-specific nuclear protein), were detected at all postnatal intervals examined, from 14 h after birth to 50 days of age. While they were present in the ovarian hilum and medulla at all ages studied, neurons first appeared in the ovarian cortex during the juvenile period (postnatal days 10-20). In all cases, the size of the neuronal soma increased significantly during prepubertal development, reaching maximal values before puberty. Some neurons were catecholaminergic, as indicated by their content of immunoreactive tyrosine hydroxylase (TH), the rate-limiting enzyme of catecholamine biosynthesis. Some showed neuropeptide Y (NPY) immunoreactivity. TH-positive neurons were seen either in isolation or clustered in ganglion-like structures in both the ovarian cortex and medulla. These results indicate that ovarian neurons are not present in all strains of rats, but when present, the chemical phenotype of some of them is of a sympathetic nature, similar to that described in primates.