Absorption of neomycin from the equine uterus: effect of bacterial and chemical endometritis

Plasma concentrations of neomycin were measured after intrauterine infusion of 3.3 mg/kg neomycin sulphate. Mares infected two hours previously with an intra-uterine infusion of beta-haemolytic streptococci absorbed approximately 12 per cent of the neomycin in both the oestrous and the luteal phases of the cycle. Normal mares in oestrus absorbed 6 per cent of the neomycin infused and luteal mares absorbed 56 per cent. In infected mares the peak plasma concentrations occurred two hours after neomycin infusion, earlier than in healthy mares. Cervical flushings after neomycin infusion in infected luteal mares revealed an increased reflux of neomycin when compared with healthy mares. Prior infusion of 30 ml of 10 per cent Lugol's iodine into the uterus resulted in 31 per cent of neomycin being absorbed by oestrous mares and 64 per cent by mares in the luteal phase. Peak plasma concentrations occurred 30 minutes after infusion in both phases. In the luteal phase the mares' absorption of neomycin may have been maximal.     

Immunohistochemical evaluation of the equine endometrium during the oestrous cycle

Endometrial biopsies were obtained from four mares during consecutive oestrous cycles on the first day of oestrus, on the day when ovulation was detected, and four and eight days after ovulation. Cycle stages were confirmed by means of rectal palpation, ultrasonography and plasma progesterone determination. Immunohistochemical evaluation of the formalin fixed biopsy specimens was performed using a peroxidase anti-peroxidase technique. Immunoglobulin (Ig)A-, IgM-, IgG(Fc)- and IgG(T)-containing cells were detected in all biopsies; with IgA- and IgG(Fc)-containing cells generally predominating. There was no cyclical trend of Ig-containing cell numbers for any isotype. Free immunoglobulins of the four classes evaluated were frequently seen in luminal epithelium, glandular epithelium and secretions, and interstitium. This study of endometrial biopsies from a limited number of cycling mares suggests the presence in the equine endometrium of free and intracellular immunoglobulins of the classes A, M, G(Fc) and G(T) without any apparent cyclical trend.     

Chemoattractant properties of conditioned medium from equine corpora lutea collected at various stages of the oestrous cycle

This study investigated the chemotactic activity of equine CL at different stages of the oestrous cycle. The purpose of this was to ascertain whether luteal tissue itself contributes to the massive influx of leucocytes around the time of natural and induced luteal regression. Corpora lutea were collected at different stages of dioestrus and after treatment with PGF2alpha. Culture medium harvested after incubation of luteal tissue for 20 h was chemotactic for both polymorphonuclear and mononuclear cells in late dioestrus (before functional regression) as well as after natural and induced luteal regression. By contrast, midluteal tissue showed no chemotactic activity. This is the first report of the ability of equine luteal tissue actively to recruit inflammatory cells in vitro and supports our earlier findings that this infiltration starts prior to functional luteolysis. We hypothesise that this early influx of inflammatory cells may play an active role in luteal regression. Further research is needed to identify the specific chemotactic factor(s).     

Changes in the dimensions of the uterus of the Beagle bitch during the oestrous cycle

Results are presented of the changes in the dimensions of the horns of the uterus during the oestrous cycle in the Beagle bitch. The data, based on seventy-three observations in fifty-three animals, indicate that from the onset of oestrus the width and thickness of the uterus increase and reach peak values 7–9 weeks later.
Résumé. On présente les résultats des changements de dimension des prolongements de l'utérus, rencontrés pendant l'oestre d'une chienne Beagle. Les données, basées sur soixante-treize observations de cinquante-trois animaux, indiquent que dès le commencement du cycle la largeur et l'épaisseur de l'utérus s'accroissent et atteignent leurs valeurs maximales sept à neuf semaines plus tard.
Zusammenfassung. Es werden die Ergebnisse der Untersuchung von Dimensionsveränderungen der Uterushörner während des östrischen Zyklus bei der Beaglehündin angegeben. Die Daten von 73 Beobachtungen an 53 Tieren lassen erkennen, dass vom Beginn des Östrus die Breite und Dicke des Uterus zunehmen und 7 bis 9 Wochen später Maxima erreichen.     

Changes in the mast cell distribution in the canine ovary and uterus throughout the oestrous cycle

This is the first study describing the relation between the phase of the oestrous cycle and the number of mast cells (MCs) in the canine ovaries and uterine horns. The total number of MCs was counted in cortex ovarii, medulla ovarii, endometrium and myometrium. The number of MCs was compared in all of these areas among the bitches in the early follicular phase, luteal phase and anoestrus. MCs were the most numerous in the early follicular phase and in the luteal phase; however, they were significantly less numerous during anoestrus. Based on the results, it was concluded that the number of MCs in ovaries and uterine horns fluctuates during the oestrous cycle. The results of this study may contribute to clarifying the role of MCs in the reproductive organs of bitches.     

Tissue concentrations of eosinophilia in the bovine oviduct and uterus of different stages of the oestrous cycle

Numbers of eosinophils in the bovine oviduct and uterus were determined during the oestrous cycle. The eosinophil numbers in the oviduct (ampulla and isthmus) and horn of the uterus during oestrus were significantly higher than during dioestrus. The number of eosinophils in the uterine cervix was lower than in the uterine horn for all stages of the oestrous cycle. In the oviduct, eosinophils accumulated in the lamina propria of the tunica mucosa, in the tunica muscularis and in the connective tissue of the tunica serosa. In the uterus, they were concentrated mainly in the upper parts of the stroma in the endometrium. Degranulation of eosinophils was observed during oestrus when they increased in number in the oviduct and uterus.     

N-acetyl- beta -D-glucosaminidase activity in the endometrial epithelium of the cow's uterus during the oestrous cycle and pregnancy

The levels of N-acetyl-beta-D-glucosaminidase (NAGase) were measured in the endometrial epithelial tissue of the bovine uterus during the oestrous cycle and during pregnancy. NAGase levels were significantly (P<0.001) higher in the epithelial tissue of the cow's uterus during the luteal phase of the cycle and during pregnancy than during the non-luteal phase. There were significantly (P<0.001) higher mean NAGase values in the epithelial than the subepithelial layers of the uterus in the two cycle phases and in pregnancy. Leucocyte numbers were significantly (P<0.05 and P<0.001) higher in the cows' uteri during the non-luteal phase than during the luteal phase and pregnancy, respectively. It is concluded that the endometrial epithelial layer is significantly active in terms of NAGase release and that this may be related to increased progesterone concentrations. In addition, the epithelial tissue (not leucocytes) appears to be the main contributor to the total NAGase activity in uterine tissue.     

Expression of oestrogen receptor,androgen receptor and progesterone nuclear receptor in sheep uterus during the oestrous cycle

Oestrogen, androgen and progesterone are involved in the regulation of uterine physiological functions, with the participation of the following proteins: oestrogen receptor (ER), androgen receptor (AR) and progesterone nuclear receptor (PGR). In this study, we used immunohistochemistry to detect the localization of ERα, ERβ, AR and PGR in sheep uterus. Additionally, we used real‐time polymerase chain reaction (RT‐qPCR) and Western blot technique to analyse their expression profiles at different stages of sheep oestrous cycle in the endometrium and myometrium. Immunohistochemical analysis showed that ERα, ERβ, AR and PGR were present in sheep uterus in oestrus, mainly in the uterine luminal epithelium, stroma, gland and myometrium. Real‐time polymerase chain reaction results showed that in the endometrium, ERα expression level was highest in oestrus. ERβ and PGR, instead, were highly expressed in pro‐oestrus. In the myometrium, ERα was highly expressed in both oestrus and pro‐oestrus, and ERβ was highly expressed in oestrus and dioestrus. Progesterone nuclear receptor expression was highest in oestrus, followed by metoestrus. In the endometrium, both receptors ERα and ERβ were abundant in pro‐oestrus, while the maximum AR protein content was found in oestrus. At this stage of the oestrous cycle, PGR protein concentration in the myometrium was significantly lower than those observed in other stages. These results suggest that these receptors are important for sheep reproductive function, as their expression at mRNA and protein levels exhibits particular time‐ and tissue‐specific profiles along the oestrous cycle.     

Hormonal control of the bovine oestrous cycle

The role of hormones in controlling the estrous cycle of cows is reviewed in the context of current research, specifically on endocrinal functions. This is central as the follicles grow on the ovaries in response to the pituitary's follicular stimulating hormone. When the ovaries produce sufficient estrogens, an ovulatory surge of luteinizing hormone is released by the pituitary. This causes the ovulation of 1 of the follicles and the growth of a corpus luteum in the follicular cavity. This corpus luteum secretes progesterone for about 2 weeks until its activity is terminated by uterine luteolysin. Control of the estrous cycle thus depends on alternate signals from the pituitary and ovaries with the end of the cycle caused by the nonpregnant uterus.     

Trypanosomosis and reproduction: I. effect ofTrypanosoma vivax infection on the oestrous cycle and fertility in the ewe

Summary Ten West African Dwarf ewes were inoculated withTrypanosoma vivax and, at varying intervals, treated subcuratively with diminazene aceturate to maintain the infection. Soon after infection all ewes and anoestrus for 40 to 96 days and 5 died by day 110 post infection. Compared to control animals, infected ewes had prolonged low levels of plasma progesterone until recovery or death. However, no gross or histological lesions were detected in the endocrine or reproductive organs. Of the survivors, the 5 that were aparasitaemic subsequently became pregnant and had normal gestations.

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Tripanosomiasis Y Reproduccion: I. Effecto E Infecciones ConTrypanosoma vivax Sobre El Ciclo Estrual Y Reproduccion En La Oveja

Resumen Se inocularon 10ovejas West African Dwarf conTrypanosoma vivax y fueron tratadas periódicamente con dosis subcurativas de aceturato de diminazene, para mantener la infección. Pronto despues de la infección, todas las ovejas presentaron anestro por 40 a 96 dias y 5 murieron 110 dias después de la infección. Comparadas con controles, las ovejas infectadas presentaron niveles bajos de progesterona plasmática, hasta recuperación o muerte. Sin embargo, no se encontraron lesiones macroscópicas ni histológicas en los órganos reproductivos o endocrinos. De las sobrevivientes, las 5 que fueron aparasitémicas quedaron posteriormente preñadas y tuvieron gestaciones normales.

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Trypanosome Et Reproduction. I. Effet De La Trypanosomose AT. Vivax Sur Le Cycle Oestral Et La Fecondite Chez La Brebis

Résumé Dix brebis naines de l'Afrique de l'ouest ont été inoculées avecTrypanosoma vivax et, à intervalles variés, traitées avec e l'acéturate de diminazène à dose non curative pour maintenir l'infection. Peu après celle-ci, toutes les brebis ont présenté un anoestrus de 40 à 96 jours et 5 sont mortes le 110e jour après l'infection. Comparées aux animaux témoins, les brebis infectées ont montré des taux peu élevés et polonges de progestérone du plasma jusqu'à leur guérison ou leur mot. Cependant, aucune lésion importante ou histologique n'a été décelée dans les organes de reproduction ou endocriniens. Parmi les survivantes, les 5 qui n'étaient pas parasitées sont entrées en gestation et l'ont menée normalement à terme.

     

Lymphocytes and T lymphocyte subsets are regionally distributed in the female goat reproductive tract: influence of the stage of the oestrous cycle

The reproductive tract of the female is a part of the mucosal system which protects from pathogens invasion. We have analysed the presence and distribution of total lymphocytes, plasma cells (antibody secreting B cells) and T lymphocytes subsets in the reproductive tract of the female goat. The influence of the oestrous cycle on the densities of lymphocytes and plasma cells of the cervix and uterus horn was evaluated in sections prepared for conventional histology. Immunocytochemistry was used for the study of lymphocyte subsets by confocal microscopy and immunoperoxidase techniques. Present results show that the reproductive tract of the goat is a site rich in lymphocytes. These cells were found mingled with the epithelial cells of the endometrium and distributed throughout the stroma. Lymphocyte aggregates were observed in the stroma. Lymphocyte but not plasma cell number changed depending on the reproductive stage of the goats. The impact of the hormonal environment was different for the cervix and uterine horn. Immunocytochemistry studies evidenced the presence of cells displaying immunoreactivity for both CD 4+ and CD 8+ antibodies in the epithelial layer and stroma of the cervix and uterine horn. These cells were more numerous in the cervix and were also found infiltrating the luminal epithelia of endometrial glands. Overall, our results indicate that lymphocyte distribution is different in the cervix and the horn, and is influenced by the stage of the reproductive cycle. In summary, CD 4+ and CD 8+ T lymphocytes subsets could be found in the endometrium of both the cervix and uterine horn of the goat reproductive tract.     

Changes in serum muscle enzyme levels associated with training schedules and stage of the oestrous cycle in Thoroughbred racehorses

Blood samples were collected twice weekly over a nine month period from 24 Thoroughbred racehorses in training at Newmarket to study the effects of daily training schedules and stage of oestrous cycle on serum enzyme levels and clinical signs of equine exertional myopathy. The sampling period extended from November to July and was performed between 16:00 h and 18:00 h so as to be at least 6 h after exercise. Serum creatine kinase, aspartate aminotransferase and plasma progestogen concentrations were measured. All horses were subjected to a similar traditional training programme. The study demonstrated marked fluctuations in serum muscle enzyme concentrations which were more pronounced in two-year-old fillies than three-year-old fillies and colts. There was no correlation, however, with the stage of oestrous cycle. It was concluded that some degree of muscle cell damage, which results in a variable increase in serum creatine kinase levels, occurs in all horses following light exercise after a rest day. Traditional flat race training may not be ideal in this respect and it is suggested that, for horses with an observed tendency towards exertional myopathy, more consistent and longer periods of less strenuous exercise may be advantageous.     

Endocrine and ultrasonographic aspects of the oestrous cycle of the mule

The blood serum concentrations of progesterone and estradiol-17beta were measured at various stages of the oestrous cycle of seven female mules, and their reproductive tracts were examined ultrasonographically at the same stages.