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Topic:Endometrium
The equine endometrium is the innermost lining of the uterus in horses, playing a vital role in reproductive health and fertility. It is responsible for providing a suitable environment for embryo development and implantation. The endometrium undergoes cyclical changes during the mare's estrous cycle, influenced by hormonal fluctuations. These changes prepare the uterus for potential pregnancy and are essential for maintaining uterine health. Various conditions, such as endometritis or endometrial fibrosis, can affect the endometrium, impacting reproductive efficiency. This page gathers peer-reviewed research studies and scholarly articles that explore the structure, function, and pathological conditions of the equine endometrium, as well as their implications for equine reproduction.
Uterine involution in mares treated with progesterone and estradiol-17 beta. Bacteriology, histology, and scanning electron microscopy were used to evaluate uterine involution in 27 mares treated with daily injections of 150 mg of progesterone and 10 mg of estradiol-17 beta, commencing within 18 hours of parturition. These findings were compared with those for 24 untreated mares at postpartum day 10 or 11. The treatment resulted in significantly (P less than 0.05) greater uterine gland proliferation. Gland density was significantly (P less than 0.05) greater in mares treated for 6 to 10 days than in those treated 2 to 5 days. The proportion of ciliated cells to secreto...
The effects of EDTA-Tris infusion on the equine endometrium. Four groups of five pony mares each were used to determine if the intrauterine infusion of EDTA-Tris solution caused adverse effects on the endometrium. The uteri of mares were infused with either saline or EDTA-Tris solution or biopsied or sham-biopsied without infusion. Acute endometritis developed in one (20%) to three (60%) mares in each group during the seven days following treatment, but there were no differences (P > 0.05) in the incidence of endometritis among the groups. Endometrial fibrosis was not evident in biopsies taken on days 14, 30 and 60 following infusion of saline or EDT...
Endometritis in the mare caused by a Coryneform organism–a case report and experimental studies. Persistent purulent endometritis in a mare was attributed to an unclassified species of Corynebacterium. Following intrauterine infusions of 20% betadine for 5 days the purulent vulval discharge ceased and the mare appeared clinically normal. Based on histological examination of endometrial biopsy samples, the severe acute inflammatory reaction had largely resolved 2 days after therapy. Three maiden mares considered resistant to bacterial endometritis received single intrauterine inoculations of 1.8 X 10(9) colony-forming units of the Corynebacterium species. The uterine response was followed ...
Amikacin sulfate in mares: pharmacokinetics and body fluid and endometrial concentrations after repeated intramuscular administration. Six mares were given 5 IM injections (at 12-hour intervals between doses) of amikacin sulfate at a dosage of 7 mg/kg of body weight. Serum amikacin concentrations were measured serially throughout the study; synovial, peritoneal, endometrial, and urine concentrations were determined after the last injection. Amikacin concentrations of the CSF were measured serially in 3 of the 6 mares; 1 of the 3 mares had septic meningitis. Mean serum amikacin concentrations peaked at 1 to 2 hours after IM injection. The highest mean serum concentration was 19.2 micrograms/ml (1.5 hours after the 5th injectio...
Seasonal variation of histomorphologic features of equine endometrium. The effect of seasonal morphologic variation of equine endometrium on histologic interpretation of periglandular fibrosis was investigated in 5 mares. Endometrial tissue was procured monthly and examined microscopically for the degree of periglandular fibrosis. A prognostic category for each mare was based on the mean number of fibrotic foci per linear field of 5.5 mm. It was found that seasonal changes reflected in endometrial glands and stroma influenced quantitative assessment of fibrosis. This occasionally resulted in a change in the assigned prognostic category. Marked nonseasonal variati...
Uterine culture in mares. A guarded, sterile swab is used to obtain samples for uterine culture. With the mare in stocks, the tail bandage and the perineum washed, the culture rod is introduced into the vagina with a gloved hand. After the rod is guided through the cervix, the guard cap is dislodged and the swab is rubbed along the endometrium, after which the rod is extracted. Samples for uterine culture should only be obtained during full estrus. Swabs should be directly plated onto agar within 2 hours of collection. Blood agar is appropriate for initial screening, but use of specialized types of agar expedites ident...
Effect of exogenous gonadal steroids and pregnancy on uterine luminal prostaglandin F in mares. Two experiments were conducted to assess the effect of exogenous hormone treatment on uterine luminal prostaglandin F (PGF). In the first experiment ovariectomized pony mares received either corn oil (21 days, n = 3), estradiol valerate (21 days, n = 3), progesterone (21 days, n = 3) or estradiol valerate (7 days) followed by progesterone (14 days, n = 4). Progesterone treated mares had higher (P less than .01) uterine luminal PGF compared with all other groups, and no differences were detected between other treatment comparisons. In Experiment II, uterine fluid was collected from 4 ovariectom...
Plasma and endometrial progesterone content following exogenous progesterone administration in mares. Intact and ovariectomized pony mares were treated with either progesterone in-oil or repositol progesterone. Serum progesterone, endometrial progesterone and endometrial histology were examined. There were no differences in serum or tissue progesterone between intact and ovariectomized mares. Serum and tissue progesterone were greater for progesterone in-oil treated mares than for repositol treated mares. Both progesterone in-oil and repositol progesterone initiated endometrial gland proliferation with no difference in response observed between the two preparations.
Prognostic value of endometrial biopsy in the mare: a retrospective analysis. A retrospective analysis was made of 79 endometrial biopsy specimens obtained from mares with histories of infertility. The specimens were classified into 3 standard prognostic categories, according to the severity of the histologic changes. The 36 mares that had few endometrial lesions (category I) had a foaling rate of 78%. The 29 mares that had more severe endometrial changes (category II) had a foaling rate of 55%. The 14 mares with the most severe endometrial lesions (category III) had a foaling rate of 35%. The pregnancy losses for each category were 9.7%, 23.8%, and 44.4%, respectively....
A quantitative study of the histological morphology of the endometrium of normal and barren mares. The density of uterine glands, height of surface epithelium, numbers of hemosiderin laden macrophages, inflammatory cells and layers of periglandular fibrosis were evaluated in uterine biopsies from 40 mares. These features were found to be highly variable in normal equine endometrium. Minor pathological changes appeared to be masked by this normal variability. Atrophy of uterine glands was recognized in mares which had been barren for more than three years. No significant differences were found between barren and normal mares in the height of epithelium, number of hemosiderin laden macrophage...
Effect of pregnancy and collection technique on prostaglandin F in the uterine lumen of Pony mares. Uterine flushings were obtained through the cervix (Method A) and through the wall of the uterus after hysterectomy (Method B) of ovariectomized Pony mares after s.c. injection of oestrogen for 1 week and progesterone for 2 weeks (Exp. 1). Non-pregnant and pregnant mares were flushed by Method A on Day 14 after ovulation and the flushings compared with those of non-pregnant mares injected i.v. with flunixen meglumine, a prostaglandin synthetase inhibitor, shortly before flushing (Exp. 3). Uterine flushings were also collected by Methods A and B from non-pregnant and pregnant Pony mares on Day ...
Preferential production and secretion of immunoglobulins by the equine endometrium–a mucosal immune system. Immunoglobulin concentrations were compared in serum and in saline uterine washings from 10 normal mares and 7 subfertile mares with chronic endometrial pathology. Samples were collected in dioestrus and in oestrus. For each immunoglobulin class (IgA, IgG, IgG(T), IgM) the results were expressed as a percentage of total immunoglobulin present in uterine washings or serum. Comparison was also made between changes in immunoglobulin concentrations between dioestrous and oestrous uterine samples, and uterine immunoglobulin concentrations between groups of mares. There was significantly more IgA in...
Results of concurrent bacteriological and cytological examinations of the endometrium of mares in routine stud farm practice 1978-1981. The results of 4024 concurrent endometrial swab and smear tests taken from maiden, barren and post-parturient mares during early oestrus, before coitus demonstrated the practical value of these tests in routine stud farm practice. The use of cytological examinations provided a more direct diagnostic test for acute endometritis and this increased the accuracy of interpretation of the bacteriological findings.
Effect of ovarian hormones on the phagocytic response of ovariectomized mares. The reaction between ovarian hormones and experimental uterine infection (Streptococcus zooepidemicus) was investigated in 3 groups, each containing 6 ovariectomized mares. Group 1 served as controls ('anoestrus'), Group 2 mares were injected with oestrogen ('oestrus') and Group 3 with progesterone ('dioestrus') over a period of 5 weeks. All mares received an intrauterine inoculation of the bacteria 1 week after the start of hormonal treatment, and the results of the challenge were examined by endometrial biopsy and swabs once weekly. At the end of Week 1 no bacteria were recovered from the ma...
Endometrial change in the annual reproductive cycle of the mare. Cervical and endometrial swabs were taken from 7 mares at various stages of the oestrous cycle. There was no consistent pattern of cell change throughout the cycle. The dominant cell in smears from normal mares was the columnar epithelial cell, especially in smears obtained during oestrus. A ciliated columnar epithelial cell was found much less frequently but appeared more often in smears before oestrus. Endometrial biopsies were also collected from 7 mares at intervals 2-3 weeks over an 8-month period from the beginning of spring to the end of autumn. There was no obvious change in the endome...
Effect of repeated biopsy sampling on endometrial concentrations of sodium benzylpenicillin following intramuscular injection in pony mares. Endometrial concentrations of sodium benzylpenicillin were determined in biopsy samples from anoestrous pony mares after intramuscular administration of the penicillin at 22,000 iu/kg. Serum samples, collected at the same time as biopsies, were also assayed for their penicillin content. In experiment 1 a single pair of blood and tissue samples was taken from each mare between five and 360 minutes after injection. In experiment 2 each mare was sampled consecutively six times (between five and 300 minutes) after injection. Both serum and endometrial concentration reached a peak between 15 and 30...
Luteolysis in mares after endometrial biopsy. The length of diestrus was not changed in 4 mares by taking endometrial biopsy specimens during estrus. In contrast, taking endometrial biopsy specimens on postovulation day 4 induced premature luteolysis and significantly (P less than 0.05) reduced the length of diestrus. A concurrent decrease in serum progesterone occurred to verify the premature luteolysis in these mares. Bacterial cultures of endometrial swab samples from these mares were negative for growth at the first estrus before and after the last biopsy procedures, indicating that luteolysis was induced by the biopsy procedure and w...
The use of endometrial biopsy in the infertile mare. The results of a study on endometrial biopsies obtained from 700 infertile mares are reported. Infiltrative endometritis was present in 51% consisting of a combination of an acute and chronic cellular response in 6%, mild chronic infiltrations in 35% and moderate to severe chronic infiltrations in 10%. Demonstrable endometrial fibrosis was found in 88% of the mares with the majority having mild (51%) or moderate (35%) changes. The age of the mares and the average number of years barren gradually increased with the severity of endometrial fibrosis, as did the combined incidence of fetal loss (e...
Aspects of genital infection and swabbing techniques in the mare. The three groups of bacteria that cause endometritis in the mare are reviewed. The different methods of swabbing are assessed and the criteria which should be observed when developing a swabbing technique listed. The choice of speculum and swabs available are described.
Scanning electron microscope studies of the endometrium of the cyclic mare. Endometrial biopsies obtained from mares at different stages of the oestrous cycle, during anoestrus and in various abnormal conditions were examined with the scanning electron microscope. Preliminary observations suggest that the patterns of secretory and ciliary activity in the uterine epithelium are similar to those observed by electron microscopical techniques in laboratory and other large domestic animals. The response of the epithelial cells to hormonal variations and infections is compared with that of the endometrium as seen with the light microscope.
The effect of intrauterine and cervical manipulation on the equine oestrous cycle and hormone profiles. Endometrial biopsy or endometrial biopsy and uterine culture taken on Day 4 after oestrus induced lysis of the corpus luteum (CL), resulting in a sharp decline in serum progesterone concentration and shortened the interoestrous interval in 8/12 and 32/33 oestrous cycles, respectively, during 2 experiments. Cervical dilatation 4 days after oestrus shortened the interoestrus interval in 5/10 and 0/5 oestrous cycles. Endometrial biopsy and culture on Days 1 and 3 after oestrus also induced CL lysis during 4 of 7 cycles. Total oestrogen (oestrone plus oestradiol) concentrations increased at the on...
Endometrial histology and post-partum mares treated with progesterone and synthetic GnRH (AY-24,031). Foal heat was significantly delayed in 15 Thoroughbred and Quarter-horse mares by 200 mg progesterone in oil from Days 5--14 post partum. Nine of these mares subsequently received daily i.v. injections of 2 mg of a synthetic GnRH preparation (AY-24,031) from Day 2 of the progesterone-delayed oestrus but this treatment did not significantly shorten oestrus or hasten ovulation. Uterine biopsies taken on Day 15 post partum from all the mares showed a mixed endometrial morphology having both oestrous and dioestrous characteristics. There was an increased proliferation of endometrial glands in thes...
