Twin reduction by PGF2α intraluteal instillation in dairy cows.

The objective of this study was to determine whether induced luteolysis of one of the two corpora lutea in twin pregnancies would provoke spontaneous twin reduction. In Experiment 1, 12 post-partum cows with two corpora lutea in the same ovary were assigned to (three cows per group): Group I, Group II, Group III or Group IV receiving into one of the corpora lutea puncture with no treatment, 0.5 mg dinoprost, 1.5 mg dinoprost and 2.5 mg dinoprost, respectively. One of the two corpora lutea showed clear signs of luteolysis on Day 2 and was practically non-detectable on Day 7 after treatment in the three cows of the Group IV. In Experiment 2, 11 cows carrying live twins with two corpora lutea on Day 28 of gestation, eight bilateral and three unilateral, received 2.5 mg dinoprost into one of the corpora lutea. Corpus luteum reduction and embryo reduction after treatment were registered in 10 and 9 cows, respectively. In bilateral twin pregnancies, four cows suffering embryo reduction remained pregnant. In unilateral twin pregnancies, membrane detachment resulted in the death of both cotwins. In conclusion, although observations were based on few animals, there seems to be a mechanism that operates locally to transfer ovarian progesterone to the uterus, and also a quantitative relationship between the amount of progesterone secreted and support of conceptuses, resulting in death of one twin embryonic vesicle when one corpus luteum regresses.

Efficacy of cloprostenol or aglepristone at 21-22 and 35-38 days of gestation for pregnancy termination in queens.

The objective of this study was to evaluate the efficacy of cloprostenol (CLO) or aglepristone (ALI) for pregnancy termination in queens at 21-22 and 35-38 days of gestation. Two experiments (EXP) were carried out to accomplish this aim. Thirty-seven 12- to 14-month-old mixed breed queens were used in a randomized design. At oestrus, queens were housed for mating with a tom, and pregnancy was confirmed by transabdominal ultrasonographic examination (US). On days 21-22 of pregnancy (EXP1) or 35-38 of pregnancy (EXP2), queens were divided into three groups (G). Queens in G1 received ALI (10 mg/kg, sc; EXP1, n = 6; EXP2, n = 6) on two consecutive days. Queens in G2 received CLO (5 µg/kg, sc; EXP1, n = 6; EXP2 = 7) on three consecutive days. Queens in G3 received 1 ml of saline solution (PLA, sc; EXP1, n = 6; EXP2 = 6). After treatment, females were monitored daily by US during for 10 days and weekly until the end of gestation. In EXP1, pregnancy was terminated in (6/6, 100%), (0/6, 0%) and (0/6, 0%), for the ALI, CLO and PLA groups, respectively (p < 0.001). In EXP2, pregnancy was terminated in (6/6, 100%), (1/7, 14%) and (0/6, 0%) for the ALI, CLO and PLA groups, respectively (p < 0.001). In both EXP, after CLO administration, animals vomited and were depressed for 30 min; but no side effects were observed in the animals in the ALI group. In conclusion, the results from this study indicate that three injections of CLO are not effective, but two injections of ALI are effective to induce abortion in queens at 21-22 or 35-38 days of pregnancy.

Partial foetal retention following aglepristone treatment in a bitch.

This short communication describes the case of partial foetal retention in an 18-month-old female French bulldog following induction of abortion owing to an undesired mating. Abortion was induced with aglepristone administered in two consecutive protocols of a dual injection 1 day apart. After failure of the first treatment to achieve abortion, 15 days later, a second treatment was administered. Delivering of aborted foetus occurred 2 days after the last administration. Five weeks after the abortion, the female showed a weak haemorrhagic vaginal discharge. On ultrasound examination, the presence of uterine wall distension as well as a puppy skull inside the uterus was observed. This clinical case makes clear that although aglepristone is a very reliable drug, follow-up of the female during treatment and in the immediate post-partum is necessary to ensure a good outcome.

ESI-Mass spectrometric and HPLC elucidation of a new ergot alkaloid from perennial ryegrass hay silage associated with bovine reproductive problems.

This case report involves four dairies in the Willamette Valley, Oregon, which experienced reproductive problems associated with the presence of a large, previously unidentified, peak eluting at 5 min in a standard ergovaline high-performance liquid chromatography assay of perennial ryegrass silage fed to those animals. Mycotoxin analysis of the silage was negative, as was serological screening of the herds for infectious bovine rhinotracheitis, bovine diarrhea virus and Leptospirosis, including culturing of urine for Leptospira hardjo hardjobovis. Prolactin concentrations were low in most cattle, consistent with ingestion of ergot alkaloids. We believe that this peak represents a novel ergot alkaloid-related compound due to its extractability with Ergosil, its detectability due to fluorescence, and its chromatographic retention between ergovaline (mw = 533) and ergotamine (mw = 581). Its molecular weight was calculated as 570 owing to the predominance of a m/z 593.5 ion in the full scan ESI(+)MS and its deduced tendency to complex with Na(+) (as m/z 593) or K(+) (as m/z 609) ions. We offer rationales for elucidation of the structure of this compound, with the closest starting point comprising an m.w. of 566-a fructofuranosyl-(2-1)-O-beta-D-fructofuranoside derivative of 6,7-secoergoline from Claviceps fusiformis. This m.w. requires modifications, such as reduction of two double bonds in the secoergoline component to give the target 570 m.w. Despite the lack of a definitive structure, the analysis herein provides a starting point for eventual elucidation of this apparently new ergot alkaloid, and to guide and encourage further investigation as to its association with endophyte toxicosis in livestock.

Induction of abortion with aglepristone in cats on day 45 and 46 after mating.

The aim of this study was to test for the efficacy and safety of the use of aglepristone for pregnancy termination on day 45 in cats. Six healthy cats were treated with 10 mg/kg aglepristone sc on day 45 and 46 after mating; six other cats served as untreated controls. The effect of treatment was monitored by general examination, vaginal cytology, ultrasonography and blood sampling for haematology and progesterone determination. Besides, interoestrus interval and next pregnancy including litter size were recorded. The efficacy of treatment was approximately 67% (4/6) with abortion occurring 4-7 days after the first injection and a sanguineous discharge and erythrocytes in vaginal smears for at least 6 days afterwards. The two treated cats that did not abort gave birth to two kittens on day 67 and had a stillbirth of a single kitten on day 71, respectively. As expected enlargement of the mammary glands and lactation were observed in all treated cats. No other treatment-induced side effects were observed. Progesterone levels at abortion were high (30-140 nmol/l), but were decreased on day 55. Aglepristone treatment did not affect fertility in following cycles. Finally, it can be concluded that late-term pregnancy termination with aglepristone is possible but due to a success rate of 67% an ultrasonographical examination 7 days after treatment is an inherent necessity to control the effect of treatment.

[Investigation of abortions and other animal health problems in relation to vaccination against Bluetongue virus in 2009]. / Abklärung von Aborten und anderen tiergesundheitlichen Problemen beim Rind im Zusammenhang mit der Blauzungenvirus-Impfung 2009.

By the distribution of a questionnaire between all Swiss cattle practitioners it was possible to investigate abortions and other animal health problems related to Bluetongue vaccination 2009. The questionnaire helped to obtain plausibility and timely relation of the reported disorders. 58 abortions in cattle and different herd health problems could be examined. Because there is no possibility to show that a vaccination itself leads to an abortion the results of proven causes of abortions prior and after Bluetongue vaccination were compared regarding their diagnosis. Due to the fact that diagnosis and solving rate of abortions did not differ before and after vaccination, the vaccination itself cannot be responsible for the abortions. Evaluation of different herd health problems showed that Bluetongue vaccination was not responsible for these disorders which often existed already prior to vaccination. Herd health problems generally have multifactorial causes what makes it difficult to asses the effect of Bluetongue vaccination in some cases.

Assessment of peripheral markers and ultrasonographic parameters in pregnant mares receiving intramuscular or intrauterine cloprostenol.

The present study aimed to compare two methods of prostaglandin-induced abortion in mares by determining blood markers (progesterone, estradiol-17ß, alpha-fetoprotein, 13,14-dihydro-15-keto-prostaglandin-F2α (PGFM)), B-mode ultrasonographic parameters, and time until loss of fetal heartbeat. It was hypothesized that intrauterine infusion of cloprostenol results in earlier fetal compromise than intramuscular administration. Ovarian structures (number and sizes of follicles and corpora lutea area), fetal heartbeat, and fetal mobility of thirteen singleton pregnancies were assessed daily by transrectal ultrasonography until induction of pregnancy termination (60 ±â€¯2 days of gestation). Mares received 500 µg of cloprostenol intramuscularly every 12 h (IM, n = 7) or once transcervically (TC, n = 6). After initial cloprostenol administration, ultrasonographic examinations were repeated at 6-h intervals until loss of fetal heartbeat was detected. Plasma progesterone, estradiol-17ß, and alpha-fetoprotein were assessed for five days before and after pregnancy loss. In addition, plasma PGFM concentrations were assessed immediately before cloprostenol administration (0 min), and then 15, 30, and 45 min, and 1, 2, 3, 4, 6, 12 h after administration. Data were analyzed using the MIXED procedure with repeated measures in SAS. Significance was set at P < 0.05. All mares lost their pregnancies within 48 h after initial cloprostenol administration, with no difference in time to pregnancy loss. There were significant effects of time starting by 12 h post-induction of pregnancy termination but there was no time by group interaction for progesterone concentrations. Estradiol-17ß and alpha-fetoprotein concentrations were not altered upon impending abortion. Concentrations of PGFM increased significantly by 2 h after cloprostenol administration, but there were no differences between groups. No time effects or time by group interaction for fetal mobility and heartbeat was detected. Expectedly, the number and area of corpora lutea decreased significantly after cloprostenol administration with no significant differences between groups. In conclusion, intrauterine administration of cloprostenol was not different from repeated systemic administration to terminate the pregnancy. Both models for early fetal loss were equivalent for the endpoints assessed herein. The present study provides evidence that transcervical cloprostenol administration technique is repeatable in different settings and results in negligible side effects. While systemic administration results in colic-like signs and may result in severe reaction.

Postnatal development in cynomolgus monkeys following prenatal exposure to natalizumab, an alpha4 integrin inhibitor.

BACKGROUND: Natalizumab is a humanized monoclonal IgG4 antibody to human alpha4 integrin that blocks the interaction of alpha4beta1 and alpha4beta7 integrins with their ligands, including fibronectin, vascular cell adhesion molecule-1, and mucosal addressin cellular adhesion molecule-1. Because alpha4 integrins and their ligands are widely involved in mammalian development, lymphopoeisis, and hematopoiesis, natalizumab may interfere with these processes. METHODS: The effects of prenatal exposure to natalizumab on postnatal development were assessed in cynomolgus monkeys at doses of 0 and 30 mg/kg administered intravenously every other day from gestational day (GD) 20 to 70 or GD 20 to term. Infants were delivered by natural birth and evaluated for general health, survival, development, and immunological structure and function at 12 or 18 months. RESULTS: An increase in abortions was seen in the first cohort of natalizumab-treated dams (39.3 vs. 7.1% in the controls) but not in the second cohort (33.3, 37.5%). Infants in the term treatment group had elevated lymphocyte ( approximately 150%) and nucleated red blood cell counts ( approximately 400%), consistent with the pharmacological effect of natalizumab, and reductions in platelet counts ( approximately 28%), which were reversible following clearance of natalizumab. No anemia was observed. Infants in the term treatment group had significantly increased spleen weights at 12 months but not at 18 months. All other experimental observations in infants from natalizumab-treated dams were comparable with those of controls. CONCLUSION: Natalizumab had no adverse effects on the general health, survival, development, or immunological structure and function of infants born to dams treated with natalizumab during pregnancy.

Abortion and neonatal mortality in sheep poisoned with Tetrapterys multiglandulosa.

Tetrapterys spp. have been reported as a cause of cardiac fibrosis, status spongiosus of the nervous system, and abortion. To study the intoxication by Tetrapterys multiglandulosa, 24 sheep were divided into 4 experimental groups of 4 sheep each and 1 control group. Groups 1 to 3, respectively, received 1, 1.5, and 3 g/kg body weight of the dry plant daily, starting on the 90th day of pregnancy. Group 4 received 1.5 g/kg from the 120th day of pregnancy to the end of gestation. All sheep from groups 2 and 3, except 1 that was submitted to cesarean delivery, aborted between 110 and 134 days of pregnancy. Seven fetuses had anasarca. Seven lambs from groups 1 and 4 were weak and died or were euthanatized. The other 2 were born weak with mild nervous signs but recovered. Cardiac fibrosis and status spongiosus of the nervous system were observed in newborn lambs and fetuses.

Morphological examination of the corpora lutea from pregnant bitches treated with different abortifacient regimes.

Different abortifacient regimes in dogs were analysed for their effect on the pregnancy corpora lutea (CL), namely, prostaglandin F2a analogue cloprostenol (CLO) combined with dopamine agonist cabergoline (CAB), or progesterone (P4) receptor antagonist aglepristone (AGL). Ovaries were collected after 6-10 days of treatment during first trimester. The CL of the control-group showed strong expression of relaxin (RLX), its receptor RXFP1 and enzymes of steroid biosynthesis (HSD) with high peripheral P4-levels. Whereas RXL, RXFP1 and HSD were lowest expressed in the CLO/CAB-group with a massive degeneration of CL and their blood vessels combined with low peripheral P4-level. The AGL-group showed less extensive CL degeneration and more intensive staining of the examined factors than CLO/CAB. In summary, all examined factors are associated with normal luteal function and are useful tools to stage luteolysis. Although both treatments have the same abortive action, their sequence of events on the CL is different.

Comparison of two doses of the GnRH antagonist, acyline, for pregnancy termination in bitches.

Gonadotropin-releasing hormone (GnRH) antagonists are particularly useful when a rapid inhibitory effect on the gonadal axis is required. The aim of this study was to test the efficacy and clinical safety of a low and high dose of the third generation GnRH antagonist, acyline, on pregnancy termination in female dogs. The effect of the antagonist on the progesterone (P(4)) serum concentration was also described. Twenty-one mid-pregnant bitches were randomly assigned to a single subcutaneous (SC) dose of a placebo (PLACE; n = 7), a low (ACY-L; 110 microg/kg; n = 6) or high (ACY-H; 330 microg/kg; n = 8) dose of acyline. The animals were followed up for 15 days. All ACY treated but no placebo-treated animals terminated their pregnancy by abortion (p < 0.01). The ACY-L and ACY-H groups interrupted their pregnancy 7 +/- 1.9 and 6.4 +/- 1.3 days after treatment, respectively (p = 0.7). A significant interaction between treatment and day was found (p < 0.01) for P(4) serum concentrations when PLACE was compared with both ACY groups. No difference was found for this hormone between both ACY groups (p > 0.05) where P(4) diminished throughout the study. The decreasing rate varied among animals and was closely related to the time of abortion when P(4) reached basal concentrations. In PLACE animals, gestation progressed normally and P(4) did not change throughout the study (p > 0.05). None of the bitches presented side effects. It was concluded that acyline safely terminated mid-pregnancy by permanently decreasing P(4) serum concentrations.

An experimental model to study resistance index and systolic/diastolic ratio of uterine arteries in adverse canine pregnancy outcome.

The aim of this study was to describe the changes in the resistance index (RI) and systolic/diastolic ratio (S/D) of the uterine arteries during mid-pregnancy abortion induction in the dog. Sixteen 30-35 day pregnant bitches were randomly assigned to either a pharmacological protocol to interrupt gestation (n = 8) or were used as untreated control group (n = 8). Doppler assessments of uterine arteries blood flow were carried out before the initiation of the protocol and then every other day up to abortion (treated group) or parturition (control group). All treated bitches aborted 6 +/- 1.2 days after initiation of the treatment (while none of the non-treated bitches aborted). Pre-treatment RI and S/D did not differ between groups (p > 0.2) while average post-treatment indexes were (mean +/- SD): 0.62 +/- 0.1 vs 0.53 +/- 0.1 (p < 0.01) and 2.96 +/- 0.9 vs 2.23 +/- 0.3 (p = 0.01), for the treated and non-treated group respectively. Correlations between days to abortion and RI or S/D were 0.75 (p < 0.01) and 0.79 (p < 0.01) and, -0.78 (p < 0.01) and -0.73 (p < 0.01) for the treated and non-treated groups respectively. In the treated group, correlations between serum progesterone (P(4)) concentrations and RI and S/D were -0.76 (p < 0.01) and -0.59 (p < 0.01) respectively. It is concluded that, during induction of abortion, RI and S/D of uterine arteries progressively increased while P(4) decreased.

The role of domoic acid in abortion and premature parturition of California sea lions (Zalophus californianus) on San Miguel Island, California.

Domoic acid is a glutaminergic neurotoxin produced by marine algae such as Pseudo-nitzschia australis. California sea lions (Zalophus californianus) ingest the toxin when foraging on planktivorous fish. Adult females comprise 60% of stranded animals admitted for rehabilitation due to acute domoic acid toxicosis and commonly suffer from reproductive failure, including abortions and premature live births. Domoic acid has been shown to cross the placenta exposing the fetus to the toxin. To determine whether domoic acid was playing a role in reproductive failure in sea lion rookeries, 67 aborted and live-born premature pups were sampled on San Miguel Island in 2005 and 2006 to investigate the causes for reproductive failure. Analyses included domoic acid, contaminant and infectious disease testing, and histologic examination. Pseudo-nitzschia spp. were present both in the environment and in sea lion feces, and domoic acid was detected in the sea lion feces and in 17% of pup samples tested. Histopathologic findings included systemic and localized inflammation and bacterial infections of amniotic origin, placental abruption, and brain edema. The primary lesion in five animals with measurable domoic acid concentrations was brain edema, a common finding and, in some cases, the only lesion observed in aborted premature pups born to domoic acid-intoxicated females in rehabilitation. Blubber organochlorine concentrations were lower than those measured previously in premature sea lion pups collected in the 1970s. While the etiology of abortion and premature parturition was varied in this study, these results suggest that domoic acid contributes to reproductive failure on California sea lion rookeries.

Retrospective case study of fetal mummification in cows that did not respond to prostaglandin F2alpha treatment.

Mummification of bovine fetuses is an uncommon condition, and cows do not always respond to treatment with prostaglandin F2alpha. The objective of the present retrospective and descriptive case study was to determine the conception rate and survival time of nonresponsive, prostaglandin F2alpha (PGF2alpha)-treated cows (n = 14), following hysterotomy or medical treatment and manual removal. Animal records from 1990 to 2005 from the Centre Hospitalier Universitaire Vétérinaire (CHUV) of the Université de Montréal were studied. Inclusion criteria were the nonexpulsion of the mummified fetus following PF2alpha treatment and absence of concomitant conditions upon physical examination. Of the animals included in the study, 36% (n = 5) became pregnant after extraction of the mummified fetus by hysterotomy and 0% conceived after medical treatment and manual extraction. In this study, hysterotomy represented an effective approach for extracting mummified fetuses from cows that did not respond to PF2alpha treatment.

Effects of different odours on the reproductive success of Mus musculus as an alternative method of control.

BACKGROUND: The house mouse (Mus musculus) is a cosmopolitan rodent that has become adapted to living in close association with humans and is considered a serious pest because it poses a risk to human health, and causes economic losses due to food and crop consumption and damage to buildings. Its control in livestock farms is achieved mainly through the application of anticoagulant rodenticides, but the effect of these compounds is limited due to the presence of resistant individuals and aversive behaviours. A potential alternative method is the use of chemical signals to reduce rodent reproductive success. In this study, we assessed the effects of odours from an unfamiliar male, 17ß-oestradiol, overcrowding, cat urine and 2,5-dihydro-2,4,5-trimethylthiazoline (TMT) on the reproductive success of laboratory Mus musculus females. RESULTS: According to the generalized linear mixed models, cat urine odour increased the proportion of abortions per female, unfamiliar male odour decreased the mean number of offspring born per female, and TMT had an overall negative effect on mean offspring production at birth and at weaning. The other odours had no significant effects on reproductive success. CONCLUSIONS: TMT seems to be the best candidate for population control because it caused a decrease in the mean number of offspring born and the mean number of live offspring at weaning. TMT also has the advantage of being available in commercial forms. To be useful for rodent management in field conditions, these results should be confirmed using wild house mice females. © 2019 Society of Chemical Industry.

CXCL12 expression in aborted mouse uteri induced by IFN-γ: Potential anti-inflammatory effect involves in endometrial restoration after abortion in mice.

Anti-inflammation is a key process to restore tissue integrity and function. CXCL12 is a homeostasis chemokine, which plays a coordinating role in organogenesis, tumorigenesis and regeneration. In the present study we found that the uterus of abortion mice showed different histo-morphological changes with the development of abortion. The expression of chemokine CXCL12 and its receptor CXCR4 in abortion uterus showed a time-dependent pattern. Compared with normal pregnancy, the expression of CXCL12 and CXCR4 did not change in the uterus of GD7 abortion mice, but increased significantly in the uterus of GD8 and GD10 abortion mice. However, the expression of IFN-γ increased significantly in the uterus of GD7 abortion mice, while there was no significant change detected in GD8 aborted mice uterus. Our further data show that the expression of CXCL12 is not regulated by IFN-γ in endometrial stromal cell culture system in vitro. The treatment of CXCL12 significantly inhibits the expression of IFN-γ in in vitro cultured stromal cells and splenic monocytes. This suggests that CXCL12 may play an anti-inflammatory role in the uterus of abortion mice to promote the process of endometrial restoration after abortion, rather than participate in the process of abortion as a response molecule of IFN-γ.

Oral exposure of rats to dienestrol during gestation and lactation: Effects on the reproductive system of male offspring.

This study was aimed at determining whether dienestrol (DIES) affects reproduction in male offspring of rats following oral maternal exposure during gestation and lactation. Pregnant rats were treated from GD 6 to PND 21. Animals received 0 (control-vehicle), 0.75, 1.5, 3.12, 6.25, 12.5, 50, 75 µg/kg bw/d of DIES. A control group -without vehicle-was also included. High DIES concentrations caused abortions at 75 and 50 µg/kg bw/d, while at 12.5 µg/kg bw/d had still miscarriages. Ten male rats per group were kept alive until PND 90 to ensure sexual maturity. Body and organ weights, anogenital distance (AGD) at PNDs 21 and 90, biochemical and sperm parameters like motility, viability, morphology, spermatozoa and resistant spermatid counts, and histopathology for sexual organs and liver were determined. An increase in organ weight (liver and sexual organs) and a decrease in AGD due to vehicle were found. A reduction of sperm motility and viability, and an increase of abnormal sperm morphology were caused by DIES, which provoked a dose-dependent prostatitis. Maternal exposure to DIES induced toxicity on the reproductive system of the male offspring, which could affect the capacity of fertilization.

Mid-gestation pregnancy termination in rabbits by the progesterone antagonist aglepristone.

UNLABELLED: The efficacy of aglepristone treatment to induce abortion in does 15 and 16 days after mating was investigated. The pregnant does were randomly allocated into two groups: For group I, aglepristone was injected twice (10mg/kg, subcutaneously) on days 15 and 16 after mating (n=10); for group II the does got no treatment but the same volume of 0.9% sodium chloride solution was subcutaneously injected at the same days of pregnancy (n=5). RESULTS: group I, termination of pregnancy was successful in all does. The mean interval between the first administration of aglepristone and the beginning of vaginal discharge was 32.4+/-5.6h (range 19-72h). Complete expulsion of all fetuses was observed in four does with first occurrences of vaginal discharge on the same day. The duration between the first occurrence of vaginal discharge to expulsion of all fetuses ranged between 21 and 130h (mean 70.2+/-12.2h). As important side effects, decrease in food consumption during abortion time and irregular mating behaviour (52.3+/-2.0 days/range 46-63) were recorded. But after this time all does were mated again, 8/10 became pregnant and they whelped normal and live kittens. Group II, all does gave birth to live kittens after a mean pregnancy length of 31.2+/-0.37 days (range 30-32 days). The mean serum progesterone (P(4)) concentrations were significantly different between control and treated does after day 20 of pregnancy (P<0.05). The results indicate that aglepristone treatment is effective to induce abortion in does and causes no serious negative effects on further fertility except a short non-receptive period after abortion and short time decrease in food consumption.

Induction of abortion with aglepristone significantly changed the expression of progesterone and estrogen receptors in canine endometrial stromal cells.

In the present study, resorption/abortion was induced between days 25 and 45 of gestation with aglepristone (group IRA, n=10). The aim was to observe the change in the distribution of progesterone (PR) and estrogen receptors (ER), in comparison to a group of spontaneous resorptions/abortions (group SRA, n=5), and a further group of normal healthy pregnant animals, ovariohysterectomized between days 25 and 45 of gestation (controls, n=7). The receptors were assessed by means of immunohistochemistry (IHC) and RT-PCR, at the placental and interplacental sites of the uterine horn as well as in the corpus uteri. Significant differences were observed between the controls on one side and the groups of resorption/abortion on the other side. The total scores of the progesterone receptors (TPR) in the placental and interplacental part of the uterine horn, was significantly lower in the endometrial stromal cells (ESC) of the control group than in those of the SRA- and IRA-group, respectively (placenta: 5.8 vs. 6.5 and 6.7, p<0.01; interplacental sites: 5.6 vs. 6.6 and 6.6, p<0.05). In contrary, the total scores of the estrogen receptors (TER) at interplacental sites and the corpus uteri, respectively, was significantly higher in the myometrial smooth muscle cells (MSMC) and the ESC (p<0.05) of the controls. We therefore conclude, that the here observed differences between groups point to an up-regulation of TPR- and a down-regulation of TER-scores in endometrial stromal cells at different uterine sites during resorption/abortion, which indicates a special role of these cells.

Histological changes of the feline cervix, endometrium and placenta after mid-gestational termination of pregnancy with aglepristone.

This study was conducted to investigate endometrial and placental structural changes that occurred in response to mid-gestational termination of pregnancy in queens using aglepristone, a progesterone receptor antagonist. Thirteen European Shorthair pregnant queens were either treated with aglepristone (10 mg/kg body weight; subcutaneously) twice on days 25 and 26 after first mating (am; group I; n = 9), or remained untreated and served as control (group II; n = 4). Queens of group I were ovariohysterectomized between days 30 and 41 am, either at the onset (n = 3) or during (n = 1) abortion and 12 h (n = 1), 24 h (n = 3) or 10 days after abortion (n = 1). Queens of group II were ovariohysterectomized on day 30 am. Tissue was collected from the cervix, and the interplacental zone as well as the paraplacenta/placental girdle of the uterus, subjected to standard histological procedures and evaluated using light microscopy. During abortion, gaps appeared within the paraplacenta and the placental girdle which were filled with blood, leading to an embryo-maternal disconnection. Blood was also observed within the uterine lumen as well as the interstitial mucosal stroma of the cervix and the placental girdle zone and probably originated from damaged venules, whilst arterioles remained intact. As the interval between abortion and surgery increased, the interstitial and luminal haemorrhages became less pronounced and completely disappeared except interstitial remnants 10 days after abortion. The endometrial regeneration was not fully completed on day 10 after abortion and a few cystically dilated glands were evident. In conclusion, abortion of queens through aglepristone given during mid-gestation is assumed to be the result of damage of uterine venules. This leads to an interstitial haemorrhages and bleeding into the uterine lumen, subsequently resulting in utero-placental detachment.