Sperm Motility and Lactate production at different sperm concentrations

Lactate production is associated with total spermatozoa concentration. It negatively affects preservation of total and progressive motility, showing an effect of by-products of anaerobic metabolism on long-term storage. Moreover, our data show that non-progressive motile spermatozoa are highly associated to lactate concentration, and thus, anaerobic glycolysis. More studies are required to determine relative contributions of aerobiosis and anaerobiosis to spermatozoa motility under different storage conditions.Peer reviewe

Glucose use and lactate production by equine fresh semen in human and equine extender

This study shows that this human semen extender doesn’t support equine semen preservation. Sperm cells’ glucose consumption and lactate production seem to be negligible, as these parameters were not affected by sperm concentrations in our study. Our results suggest that spermatozoa are able to cleave complex carbohydrates as glucose concentration in INRA96 increased over time

Uterine fluid contains factors inhibiting myeloperoxidase enzymatic activity in mares

peer reviewe

Immunohistochemical expression of Myeloperoxidase in the equine endometrium

editorial reviewe

Cas clinique: Fibrome Ovarien chez une jument - Considérations hormonales

peer reviewedThis report shows that, as in humans, AMH as well as steroids productions are low in case of ovarian fibroma, thus preserving normal cyclicity

A case of true hermaphrodism in a horse

peer reviewedTrue hermaphroditism in horses, is a complex and poorly under- stood disorder of sexual development characterized by the presence of both male and female gonads as separate organs or in a combined structure called ovotestis. A 3-year-old Spanish nullipa- rous mare with a history of stallion behaviour and an abnormal reproductive exam was presented at the Equine Clinic of the University of Li ege. Externally, a small vulva with an enlarged clitoris was observed. Transrectal ultrasonography showed a thin (<1 cm) uterus, leading to a small heterogeneous structure in the normal place of the left ovary. No structure could be identified in the presumed location of the right ovary. Speculum exam was compatible with a vaginal agenesis, as the cervix opened craniad the urethral meatus. Oestradiol, progesterone and testosterone concen- trations were compatible with a stallion’s endocrinology. Gonads were laparoscopically found in the usual location of the ovaries in both flanks and excised. Histopathology of both gonads showed atrophic testicular tissue with hyperplastic Leydig cells. The left gonad also contained ovarian tissue with some scarce primordial follicles. Clitoral enlargement is the first symptom most commonly identified in animals with true hermaphroditism and can be explained by the production of testosterone by the gonads, however, the aetiology of the vaginal agenesis is unknown. True hermaph- roditism in horses is generally related to 64XX syndrome with or without SRY gene translocation (impending karyotyping analysis). After 5 days the mare was discharged from the clinic, and in absence of testosterone the stallion behaviour disappeared in a couple of months

A case of Longitudinal Vaginal Septum in a mare

LVS occurs when there is failure in the fusion of müllerian ducts or in the regression of the vaginal septum. Primary or secondary cause of infertility, increases the risk of dystocia or alter sport performance. It is most likely under-diagnosed as it is often asymptomatic and an incidental finding

Can serum progesterone be used to decide altrenogest supplementation discontinuation in problem pregnancies in mares?

Use of oral altrenogest as exogenous progesterone (P4) in mares in an effort to maintain high-risk pregnancies is a widespread practice. Treatment is sometimes initiated as early as 2 days after ovulation. Timing when it can safely be stopped is frequently uncertain and therefore, supplementation is often continued until 100-120 days, when the placental secretion of progestagens has taken over. The aim of this study was to determine if altrenogest interfered with progesterone assay and if timing of altrenogest administration discontinuation could be based on the blood concentration of P4. Data were obtained from 7 healthy standard breed mares in seasonal anoestrus and in dioestrus. Mares were considered anoestrus when no follicles larger than 15 mm in diameter or corpus luteum (CL) were found at 2 consequent ultrasound examinations 7 days apart. They were confirmed dioestrus based on an observed ovulation and the presence of a CL 2 days after. Mares were treated with 0.044 mg/kg of altrenogest (Regumate®, Intervet, Boxmeer, Netherlands) orally once per day during 12 days beginning at any time for the anestrus group and at day 2 after ovulation for the dioestrus group. Blood was collected at day 0, 6, 12, 18 right before altrenogest administration and the serum was stored at -20°C until analysis. P4 concentration was obtained by radioimmunoassay and altrenogest by liquid chromatography-mass spectrometry. Differences in P4 and in altrenogest concentrations between different sampling days were determined by Friedman non parametric test. Concentrations of altrenogest before treatment were almost not detectable (negative control). At day 6, they were significantly higher (p<0.05), and were back to basal, almost not detectable values at day 18, in both groups. P4 concentration was basal with values < 0.4 ng/ml all through the experiment in the anoestrus group. In the dioestrus group, P4 concentration was variable from one mare to another, but it was significantly higher in mid-dioestrus (day 6) as compared to the time of the impending next oestrus (day12). No cross-reaction between P4 and altrenogest assays was observed as illustrated by the fact that concentration of P4 during anoestrus remained basal with or without supplementation. Despite the treatment, the variation of P4 over time was as expected in both groups. Altrenogest was no longer detectable 6 days after the last administration. Further studies with larger numbers and sampling in dioestrus to compare P4 levels in treated and untreated mares to investigate the potential effect of altrenogest on endogenous P4 production by the CL are needed. However, our experiment shows that P4 levels assayed by RIA can be trusted to evaluate if the secondary CL’s have become functional and can thus maintain the pregnancy while oral altrenogest supplementation is discontinued

Assessment of Myeloperoxidase activity in raw equine fresh semen

In previous studies [1], myeloperoxidase (MPO), a pro-oxidant enzyme, has been shown to be partially inactivated in commercial equine semen extenders. The aim of this study was to determine MPO concentration and activity in fresh equine semen and in supernatant of semen diluted with a cristalloïd solution after cushionned centrifugation. Three stallions have been collected 5 times at 2 day-intervals. Semen concentration was assessed with Nucleo Counter sp100. A sample containing 100x106spz was then immediatly frozen (-80°C) before assays. A volume of semen containing 500x106spz was diluted 3 times with PBS (1v/3v). Samples were centrifuged (1000xg, 20 minutes). One milliliter of supernatant was sampled and stored at -80°C before assays. Total MPO concentration was assayed by commercial enzyme-linked immuno-sorbent assay and active MPO concentration was assayed by specific immunological extraction followed by enzymatic detection as previously described in our earlier paper [1]. As all values were not normally distributed, Kruskall-Wallis test was used to analyse differences between medians and Spearman test was used to determine correlations. Median total and active MPO concentrations in raw semen were respectively 580500ng/mL and 1.098ng/ mL. Median total and active MPO concentration in semen supernatant extended with PBS (1v/3v) were respectively 107500ng/mL and 0.236ng/mL. In raw semen, total and active MPO concentrations were highly correlated (r=0.7096; p=0.0030). However, in semen supernatant extended with PBS (1v/3v), they were not (r=0.2121; p=0.4479). Total MPO concentrations were similar to those observed in our previous papers [1]. When concentration observed in supernatant is compared to that observed in total raw semen (cells and supernatant), we observe that MPO in raw semen is higher than in supernatant, even after correction for dilution. This confirms that cellular part of semen contains MPO and releases it during cold-chock. Without any large proteins in the extender medium, MPO activity can be assessed in raw semen and in its supernatant. Active MPO concentrations are very low when compared to total MPO concentration, (nearly one million times). Concentration of active MPO in supernatant corrected for dilution was also lower than concentration observed in raw complete semen, also confirming active MPO release by cellular part of semen. Association of total and active MPO concentration is supporting this observation. This study confirms our previous assessments [1] that active and total MPO are released by non sperm-cells during cold shock

Raw semen concentration directly influences CASA velocity pathways

We observed an influence of the stallion on volume, spermatozoa concentration and all CASA parameters (p<0.0001), which are highly dependant on each other due to geometrical association of these data. That stallion effect may have interfered with the associations we observed as stallions seem to have specific concentration and motility pathways. More studies, with more replicates, will allow comparing results from a same stallion and further establish the correlations we report here