Assessment of Age Effects on Ovarian Hemodynamics Using Doppler Ultrasound and Progesterone Concentrations in Cycling Spanish Purebred Mares

In equine reproduction, accurate and timely detection of the moment of ovulation is of great importance. Power Doppler ultrasound technology is a non-invasive method that enables to assess the morpho-echogenic features and blood flow changes during the estral cycle in mares. The objective of the present study was to evaluate the influence of age on ultrasonographic parameters (follicular diameter, follicular blood flow—FBF, corpus luteum (CL) area and corpus luteum blood flow—CLBF) and blood plasma progesterone concentrations in cycling Spanish Purebred mares (15 less than 8 years old and 15 equal o higher than 8 years old). The ultrasound images obtained were analyzed with the Image Colour Summarizer software, which allows the quantification of the pixels of each image. Young mares had significantly higher FBF, CLBF and plasma progesterone levels. Moreover, linear regression analysis showed that blood progesterone levels could be predicted in both groups from CLBF with moderate precision and accuracy. In conclusion, Power Doppler was useful to assess ovarian hemodynamics. Our results support that age is a factor that significantly influences FBF and CLBF as well as blood progesterone concentration in mares. More studies would be needed to develop high precision and accuracy predictive models of blood progesterone concentration from CLBF measured by Power Doppler.

Effects of stereotactic surgery on the anterior hypothalamus (HA) on the estrous cycle: Role of the dopaminergic system in spontaneous ovulation in the rat

We evaluated the function of dopaminergic receptors (DAR) of the anterior hypothalamus (AH) on the estral cycle (EC) regulation and spontaneous ovulation by a single microinjection (MI) with the dopaminergic antagonist haloperidol (HLP) in adult rats. One hundred thirty nine rats that exhibit forth-day estral cycles (cyclic animals: CA) received a stereotaxic surgery (STXS) on the right, left or both AH sides and were distributed in three different groups with a MI of 1 µL of: HLP (15 µg) or dimethyl-sulfoxide (vehicle) or other false MI group. All the animals with STXS were sacrificed in next vaginal estrus (VE) exhibited and the ova shed (OS) counted. In sixteen AC, the OS were counted at VE and forming a control group. The STXS affected the animals EC: just 59/139 exhibited a short EC (SEC) with 4.6±0.1 days compared with 80/139 that exhibited a long EC (LEC) of 13.6±0.2 days. False or HLP MI diminished OS just in animals exhibiting a SEC. STXS affects neuroendocrine processes controlling EC length when cutting dorsal connections to AH. The DAR of the AH participate on ovarian mechanisms of follicular selection.

Follicular Development and Secretion of Ovarian Hormones during the Juvenile and Adult Reproductive Lives of the Myelin MutanttaiepRat: An Animal Model of Demyelinating Diseases

Infertility and reproductive problems have been reported in women with several neurological disorders, for example, demyelination. However, the physiology of such problems has remained unknown so far. Thetaieprats are an animal neurological model that initially shows a hypomyelination followed by a progressive demyelination of the central nervous system. This animal has reproductive problems, and the aim of this work is to characterize the follicular development, secretion of ovarian hormones, and presence of noradrenaline in the ovaries of the femaletaieprats in the juvenile and adult stages. Thetaieprats have low body weight (approximately 19% less than that of SD rats), a delay of 4 days in the age of vaginal opening, and an irregularity in the estrous cycle by the absence or prolongation of some estral cycle stage. In the juvenile stage, we observed a decrease of approximately 44% in the total number of follicles with a 15% increase of atresia and an 80% decrease in the fluorescence intensity of catecholamines in the ovaries, with a 21% increment in plasma concentrations of testosterone. In the adult stage, we observed follicular cysts and a 50% decrease in fluorescence intensity of catecholamines in the ovaries, with changes in the secretion of ovarian hormones, an increase of 20 times in progesterone, and a decrement of a half in estradiol. The demyelination intaieprats affects follicular development and steroidogenesis in the early stages of the animal’s life, and this is maintained until adulthood.

Estrus cycle monitoring of captive collared peccaries (Pecari tajacu) in semiarid conditions

Collared peccaries (Peccary tajacu) are among the most hunted species in Latin America due the appreciation of their pelt and meat. In order to optimize breeding management of captive born collared peccaries in semiarid conditions, the objective was to describe and correlate the changes in the ovarian ultrasonographic pattern, hormonal profile, vulvar appearance, and vaginal cytology during the estrus cycle in this species. During 45 days, females (n=4) were subjected each three days to blood collection destined to hormonal dosage by enzyme immunoassay (EIA). In the same occasions, evaluation of external genitalia, ovarian ultrasonography and vaginal cytology were conducted. Results are presented as means and standard deviations. According to hormonal dosage, six estrous cycles were identified as lasting 21.0 ± 5.7 days, being on average 6 days for the estrogenic phase and 15 days for the progesterone phase. Estrogen presented mean peak values of 55.6 ± 20.5 pg/mL. During the luteal phase, the high values for progesterone were 35.3 ± 4.4 ng/mL. The presence of vaginal mucus, a reddish vaginal mucosa and the separation of the vulvar lips were verified in all animals during the estrogenic peak. Through ultrasonography, ovarian follicles measuring 0.2±0.1 cm were visualized during the estrogen peak. Corpora lutea presented hyperechoic regions measuring 0.4±0.2 cm identified during luteal phase. No significant differences (P>0.05) between proportions of vaginal epithelial cells were identified when comparing estrogenic and progesterone phases. In conclusion, female collared peccaries, captive born in semiarid conditions, have an estral cycle that lasts 21.0±5.7 days, with estrous signs characterized by vulvar lips edema and hyperemic vaginal mucosa, coinciding with developed follicles and high estrogen levels.

Protective Effect of VaginalLactobacillus paracaseiCRL 1289 against Urogenital Infection Produced byStaphylococcus aureusin a Mouse Animal Model

Urogenital infections of bacterial origin have a high incidence among the world female population at reproductive age. Lactobacilli, the predominant microorganisms of the healthy vaginal microbiota, have shown a protective effect against the colonization and overgrowth of urogenital pathogens that increased the interest for including them into probiotics products assigned to restore the urogenital balance. In the present work, we determined in a mouse animal model the capability ofLactobacillus paracaseiCRL 1289, a human vaginal strain with probiotic properties, to prevent the vaginal colonization of a uropathogenic strain ofStaphylococcus aureus. Six-week-old female BALB/c mice, synchronized in their estral cycle, were intravaginally inoculated with two doses of109lactobacilli before challenging them with a single dose of105or107CFU ofS. aureus. The vaginal colonization of both microorganisms and the effect on the vaginal structure were determined at 2, 5, and 7 days after pathogen inoculation. Control mice and those challenged only with the pathogen showed an insignificant lactobacilli population, whereas105lactobacilli/mL of vaginal homogenate were recovered at 2 days after challenge from theL. paracaseiCRL 1289 and the probiotic + pathogen groups, decreasing this number on the following days. The treatment withL. paracaseiCRL 1289 decreased significantly the number of staphylococci recovered at 2 and 5 days when mice were challenged only with105CFU of pathogen. The inoculation ofS. aureusproduced a remarkable inflammatory response and structural alterations in the vaginal mucosa that decreases in a significant manner when the mice were protected withL. paracaseiCRL 1289. The results obtained suggest that this particularLactobacillusstrain could prevent the onset of urogenital infections by interfering with the epithelial colonization by uropathogenicS. aureus.