Transport of spermatozoa in the reproductive tract of the bitch: observations through uterine fistula

Using unilateral uterine fistulas, the time required for spermatozoa to reach the end of the fistula after natural mating, artificial insemination (AI) in a normal standing posture (NP), and AI standing on the head (SH) was investigated in each of three stages of estrus. Conceptivity in these bitches was also investigated. Five experimental bitches were tested during a total of 8 estrous periods. The results are as follows; the time required for spermatozoa to reach the end of the fistula was almost the same in the early and middle stages, i.e., 30 sec to 1 min after natural mating and SH and less than 2 min for half the bitches in NP, although no intrauterine transport could be observed in the other half. In most cases of mating during the late stage no spermatozoa were found after any of the 3 methods of insemination. Five animals became pregnant in these experiments, but the other three failed to conceive. The implantation of fertilized ova occurred also in the fistulated uterine horn in all cases of pregnancy.     

Acrosin system of dog spermatozoa and reproductive tract secretions

The aim of this study was to determine the activity of proacrosin and acrosin in spermatozoa originating from the sperm-rich fractions (SRF) and whole ejaculates (WE) of dog semen. In addition, experiments were conducted to determine the activity of antitrypsin inhibitors in the fluids of different ejaculate fractions and whole seminal plasma. Ejaculates were collected from five dogs of mixed breed and one Beagle dog (aged from 2 to 9 years). In the SRF, it was confirmed that the activity of the free acrosin form was predominant (acrosin/proacrosin; 2.38 +/- 0.22/1.05 +/- 0.08 mIU/10(6) spermatozoa). On the other hand, spermatozoa originating from the WE exhibited significantly higher (p < 0.05) proacrosin activity (proacrosin /acrosin; 2.19 +/- 0.19/1.30 +/- 0.11 mIU/10(6) spermatozoa). Furthermore, acrosin inhibitor activity was lower in the fluids of the pre-sperm fraction (0.09 +/- 0.006 IU/cm3), whereas it was higher in the fluids of the post-sperm fraction (0.11 +/- 0.007 IU/cm3). Using PAGE analysis, the antitrypsin activity of the enzyme was represented by the presence of one electrophoretic band in the fluids of the pre-sperm and post-sperm fractions and whole seminal plasma. Furthermore, two electrophoretic bands were detected in the fluids of the SRF. The findings of this study indicate that specific proteinase inhibitors present in the individual ejaculate fractions of dog semen may act by stabilizing the sperm acrosin system.     

Urogenital tract infection in the bitch

The establishment of urinary tract infection and pyometra in the bitch seems to have some characteristics in common, such as similar bacteria, association with kidney pathology and similar age disposition. both diseases are regarded as an ascending infection from the vagina. The ecological factors determining the host-microbe relationship, the protective mechanisms and the methods of diagnosis are discussed.     

Urogenital tract infection in the bitch

The establishment of urinary tract infection and pyometra in the bitch seems to have some characteristics in common, such as similar bacteria, association with kidney pathology and similar age disposition. Both diseases are regarded as an ascending infection from the vagina. The ecological factors determining the host-microbe relationship, the protective mechanisms and the methods of diagnosis are discussed.

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Kurzfassung Das Auftreten von Infektionen des Urogenitaltraktes und Pyometra scheint bei der Hündin gemeinsame Charakteristika zu haben. Gefunden wurden ähnliche Bakterienspezies, eine Assoziierung mit Veränderungen in der Niere und eine Altersdisposition. Beide Erkrankungen werden als von der Vagina aufsteigende Infektionen angesehen. Ökologische Faktoren, die das Erreger-Wirts-Verhältnis beeinflussen, Schutzmechanismen und diagnostische Methoden werden diskutiert.

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Resume Les affections du tractus urinaire et le pyomètre de la chienne semblent être provoquées par des bactéries voisines. De plus elles sont retrouvées chez des animaux d'âge comparable et sont associées à une pathologie rénale. Ces deux types d'affection ont une origine ascendante à partir du vagin. Les facteurs écologiques déterminant les relations hôtes-microorganismes, les moyens de défense et les méthodes de diagnostic sont discutés dans cet article.

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Riassunto Lo stabilirsi di infezioni a carico del tratto urogenitale e la piometra nella cagna sembrano avere alcune caratteristiche in comune, come l'intervento di agenti batterici simili, l'associazione con la patologia renale e una predisposizione simile legata all'età. Ambedue le malattie vengono considerate come infezioni vaginali ascendenti. Vengono discussi i fattori alla base della relazione ospite-germe, i meccanismi di protezione e le metodiche diagnostiche.

     

Detection of intravaginal spermatozoa after natural mating in the bitch

Mismating is one of the most frequently presented reproductive problems presented to veterinarians. Confirming whether or not a mismating has occurred is necessary to determine if therapy will be instituted. Detection of spermatozoa in the vagina is irrefutable evidence of copulation; however, absence of sperm in a vaginal cytology cannot rule out coitus. In order to improve detection of spermatozoa post-coitus, a prospective study was initiated utilizing natural breedings of purebred beagles.     

The normal endoscopic appearance of the caudal reproductive tract of the cyclic and non-cyclic bitch: post-uterine endoscopy

Endoscopy of the caudal reproductive tract, or post-uterine endoscopy, is a method of examining the mucosal aspect of the vagina and vestibule/vulva of the live bitch. In this study the post-uterine, or caudal, reproductive tracts of forty-five bitches of pedigree and mixed ancestry were examined endoscopically. The instrumentation and method of endoscopic examination are described. The endoscopic appearance of the mucosal aspect of the vagina, vestibule and vulva was observed during anoestrus and several phases of the sexual cycle, and in the spayed bitch. Visual records made during endoscopy were compared with the exfoliative vaginal cytology and behavioural responses. The results obtained indicate that post-uterine endoscopy is a relatively rapid and accurate method of detecting the sexual status of the bitch, and compared well with the other methods used in this study. It is suggested post-uterine endoscopy also has a value in allied investigative procedures or reproductive processes.     

Antioxidant defence system of boar cauda epididymidal spermatozoa and reproductive tract fluids

Antioxidants secreted by the reproductive tract protect spermatozoa against the toxic effects of reactive oxygen species (ROS) after ejaculation. This study aimed at characterizing the level of antioxidant protection in boar cauda epididymidal spermatozoa and fluids of the cauda epididymidis, vesicular and prostate glands. Also, this study investigated the effect of a 5-h period of dialysis on the antioxidant capacity of boar seminal plasma. Superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), glutathione transferase (GST) and phospholipid hydroperoxide glutathione peroxidase (PHGPx) activities were monitored in the cauda epididymidal spermatozoa or reproductive tract fluids. Also, the concentrations of total glutathione (GSH + GSSG), L-ergothioneine (ERT) and l-ascorbate and the total antioxidant status (TAS) of the fluids were measured. It was found that the cauda epididymidal spermatozoa exhibited high SOD activity and relatively low activity of PHGPx. The relative amounts of GPx, GR and GST activities in the cauda epididymidal spermatozoa were negligible, whereas CAT activity was undetectable. Greater SOD activity was found in the fluids of the cauda epididymidis and prostate gland. Furthermore, the prostate gland fluid appeared to be the main source of CAT activity in the seminal plasma, whereas the highest level of GPx activity was derived from the cauda epididymidal fluid. The reproductive tract fluids exhibited negligible amounts of GR and GST activities. It seemed that the significant amounts of GSH + GSSG, ERT and L-ascorbate in the reproductive tract fluids could have an ameliorative effect on the level of TAS in the seminal plasma. Dialysis had a marked effect on the total antioxidant capacity of the seminal plasma, which was manifested in greater activity of SOD and GPx. The findings of this study confirmed that the scavenging potential of the seminal plasma is dependent on the contributions of different antioxidants, originating in various fluids of boar reproductive tract.     

Physiological changes in fowl and turkey spermatozoa during in vitro storage

1. Although early work on semen storage has been rather empirical in approach, only basic research can provide a framework of biological mechanisms from which improvements in the techniques of cryopreservation and liquid semen storage can progress logically. 2. A major drawback in this work has been the lack of adequate tests for quantitating and differentiating aspects of 'fertility'. 3. Basic research has now provided techniques for assessing: sperm fertilising ability in terms of numbers of fertile eggs; the efficiency of hens' oviducts at accepting and retaining spermatozoa, and sperm 'quality' as motility, metabolism and plasma membrane patency. 4. These techniques may be used for a more critical assessment of the effects of both cryopreservation and liquid semen storage on sperm function, although the integrity of sperm surface proteins may be a more sensitive variable which has yet to be measured. 5. Further improvements in sperm cryopreservation technology are best approached through an understanding of the fundamental cellular and molecular changes which take place during freezing; thus far little is known of such changes in avian spermatozoa. 6. The ideal milieu for maintaining spermatozoa in liquid semen storage should mimic the environment of the oviducal sperm storage tubules; elucidation of the factors involved in progressing steadily.     

Endometrial cytology of the normal bitch throughout the reproductive cycle

Samples for endometrial cytology were collected both from live bitches using transcervical uterine cannulation (n=48) and postmortem (n=10). The cells identified were endometrial epithelial cells, leucocytes, erythrocytes, spermatozoa, bacteria and cervical or vaginal cells. The endometrial epithelial cells varied morphologically throughout the reproductive cycle and had signs of degeneration during late dioestrus and during early and mid-anoestrus following dioestrus and postpartum. Neutrophils were the most common leucocytes observed during pro-oestrus, oestrus, dioestrus and early pregnancy, and lymphocytes during anoestrus. Macrophages were frequently seen during anoestrus. Erythrocytes were found in variable numbers at all stages of the reproductive cycle. Spermatozoa were detected in samples collected during oestrus and early pregnancy in bitches which had their last mating one to three days previously. Bacteria were commonly observed during pro-oestrus and oestrus. Cornified cervical or vaginal cells were present during pro-oestrus and oestrus. This study demonstrated that the numbers, types, proportions and morphology of ceils in endometrial cytological samples from normal bitches varied throughout the reproductive cycle.     

Mechanisms of sperm storage in the female reproductive tract: an interspecies comparison

Once semen has been collected for artificial insemination, it is diluted into extenders designed to prevent its deterioration over the period prior to insemination. If the semen is not frozen, the extenders provide protection for a period of a few hours to a few days, depending on species. Despite the efforts of biotechnologists to increase the duration of storage without compromising fertility, there has been relatively little progress for many years. However, comparative studies in diverse species have revealed that long-term sperm storage (up to months and years) within the female reproductive tract is relatively commonplace in reptiles, fishes, birds and amphibians. Even among mammals, some species of bat have evolved mechanisms for storing spermatozoa for several months in the uterus or oviduct so that they can mate in the autumn but postpone fertilization until the spring. We currently know little about the mechanisms that support such long-term sperm storage, mainly because evidence from such species is either absent or fragmentary. Nevertheless, parallels between mammalian and other systems, where spermatozoa are sequestered in sperm storage tubules, suggest that the enclosure of spermatozoa within pockets of epithelial cells may be sufficient to achieve long-term sperm storage. In addition, recent evidence from sperm-storing bats has suggested an alternative, or additional, hypothesis that the modulation of apoptosis within epithelial cells is important in controlling sperm survival. Despite a lack of direct experimental evidence from a wide variety of species, I propose that there is now enough evidence to warrant investigation of these hypotheses.     

Diagnostic imaging of the reproductive organs of the bitch. Methods and limitations.

This article reviews diagnostic radiology and ultrasonography of the reproductive tract of the bitch. The techniques and limitations of these imaging modalities are described. The applications of these techniques in the bitch for illustrating reproductive disorders are included.     

Uterine, cervical and vaginal microflora of the normal bitch throughout the reproductive cycle

Samples for microbiological culture were collected from the uterus of bitches using transcervical uterine cannulation (31 samples, 23 bitches) and from the uterus, cervix and vagina post mortem (19 bitches) at all stages of the reproductive cycle. Samples were cultured for aerobic and anaerobic bacteria and for aerobic mycoplasmas. Bacteria were always found in the uterus during prooestrus and oestrus (12 positive in 12 cultures) and rarely at other stages of the reproductive cycle: during anoestrus (one in 14) and other stages (none in 24). When microorganisms were detected at three sites post mortem, those found in the cervix and vagina were always of the same species as those found in the uterus. In six out of 13 instances, microorganisms were found in the cervix or vagina when none were found in the uterus. The mean number of isolates, number of bacteria seen in uterine cytology and bacterial growth were greater (P < 0–005) during oestrus and pro-oestrus than at other stages. Bacteria isolated from the uterus, in order of frequency, were Escherichia coli, Haemophilus species, α-haemo-lytic streptococci, Corynebacterium species, Streptococcus canis, Alcaligenes faecalis, Bac-teroides species, Pasteurella species and Proteus mirabilis. No mycoplasmas were cultured from the samples. This study indicates that the uterus of the normal bitch has a uterine microflora during pro-oestrus and oestrus that is similar to that of the vagina and cervix.     

Inflammation in the bovine female reproductive tract

Inflammation of the reproductive tract of a cow occurs when the physical and functional barriers to contamination are breached or specific infection occurs. Commonly, contamination occurs at parturition and to a lesser extent at estrus. Uterine contamination following calving is common, but most healthy cows are able to clear the uterus of bacteria in the first 2 to 3 wk after calving. Persistent infections are more likely to be caused by Actinomyces pyogenes. Specific venereal infections tend to be more host-adapted and produce a lower grade inflammation. Nonspecific bacterial contamination of the endometrium generally induces a neutrophilic influx into the stratum compactum and uterine lumen. Neutrophils phagocytize bacteria with the aid of opsonins in the uterine fluid. Mast cells and eosinophils may also contribute to the inflammatory reaction, which may damage the surface epithelium and release vasoactive substances that allow leakage of serum antibodies into the uterine secretions. Specific antibodies of immunoglobulin (Ig) isotype A, M, G1, and G2 in uterine secretions have been described. In model species, the immune capability of the uterus is influenced by steroid hormones, especially estradiol, which increases secretory component and both IgA and IgG content in uterine secretions and increases the activity of antigen-presenting cells in the uterus. Similar cyclic fluctuations in immune components have been described for cows, including changes in the population of subsurface cytotoxic and helper T cells and changes in the expression of major histocompatibility II antigen on surface cells.     

Immunity in the female sheep reproductive tract

Immune surveillance in the female reproductive tract is dependent on the interplay of many factors that include the expression of pattern recognition receptors on epithelial cells, resident leukocyte populations and hormones, none of which are uniform. The lower reproductive tract must accommodate the presence of commensal organisms whereas the upper reproductive tract is sterile. However, the upper female reproductive tract has its own immunological challenge in that it must tolerate the presence of a semi-allogeneic fetus if pregnancy is to succeed. So, immune activation and effector mechanisms to control pathogens may be qualitatively and quantitatively different along the reproductive tract. Our knowledge of innate and adaptive immunity in the sheep is less comprehensive than that of human or mouse. Nevertheless, comparative studies suggest that there are likely to be conserved innate immune sensory mechanisms (e.g. Toll-like receptors) and defence mechanisms (anti-proteases, defensins) that combine to limit infection in its early stages while shaping the adaptive response that leads to immunological memory and long-term protection. There are many pathogens that target the reproductive tract, and in particular the placenta, where specialised immunoregulatory mechanisms are operational. Among such pathogens are bacteria belonging to the genera Chlamydia/Chlamydophila that chronically infect the reproductive tracts of sheep and humans and ultimately cause disease through inflammation and tissue damage. An understanding of the immunological microenvironment of the reproductive tract is important for the design of novel control strategies to control chlamydial disease.