Lectin binding patterns in normal canine endometrium and in bitches with pyometra and cystic endometrial hyperplasia

Cystic endometrial hyperplasia (CEH) and pyometra in the bitch are dioestral syndromes, supposed to be caused by hormonal disturbances and changes in endometrial steroid hormone receptor levels. Histologically, the endometria show cystic dilated glands and, if bacteria succeed in invading the uterus, pyometra may develop in the following metoestrus. In this study, lectin histochemistry was performed on paraffin sections to compare carbohydrate expression of uterine glands and surface epithelium in healthy dogs and in dogs with CEH and pyometra. Lectin binding is a useful tool to identify glycoconjugates, especially of the glycocalyx, which has essential functions in the endometrium during reproduction. Uterine tissue was obtained from 18 healthy bitches in metoestrus or anoestrus and 18 bitches with a clinical diagnosis of CEH or pyometra. Normal endometria showed cycle-dependent changes in SBA, PNA, HPA and UEA binding during metoestrus and anoestrus. LCA did not show cycle-dependent changes and WGA bound to Golgi regions in the apical parts of surface epithelial cells only in metoestrous. Endometria with inflammatory alterations lost cycle-specific lectin binding patterns and, with increasing severity of pathological changes, showed a marked decrease in binding intensity to the glandular and surface epithelial glycocalyx and secretions. In dogs with CEH, unaltered glands with generally strong lectin binding to the glycocoalyx and Golgi regions were found adjacent to altered glands. The decrease of lectin binding in pyometra cases is supposed to be a result of glandular exhaustion after cystic hyperplasia. In addition, bacterial adhesion to sugar residues on the uterine surface epithelium might impede lectin binding.     

Anatomic basis of endometrial cytology

A comparative cytologic and histologic study on 700 hysterectomy specimens showed that the cytologic evaluation of exfoliated cells from the uterine cavity did not correspond to the findings of the histologic examination of the endometrium in about 33% of sexually mature and 30% of postmenopausal women. The findings of both methods did not always coincide because the epithelial cells in the imprints or smears and the epithelial cells lining the glands in the histologic specimens belonged to structures that anatomically have little in common, one being superficial epithelium of the endometrium and the other being the glandular epithelium in the deep layers of the mucosa. This explains the false-negative results in the cytologic examination of the endometrium, especially in cases of glandular hyperplasia and early carcinoma, in which the foci of proliferation are initially covered by small and inactive surface epithelial cells and are inaccessible to cytologic investigation. False-positive cytologic results may occur in cases of irritated surface epithelium in chronic endometritis; this may also happen in women using an intrauterine device, during estrogen therapy, in regenerating mucosa after desquamation or curettage, in early pregnancy and after spontaneous abortion.     

Possible role for insulin-like growth factor-I in the pathogenesis of cystic endometrial hyperplasia pyometra complex in the bitch

Cystic endometrial hyperplasia (CEH) is an important pathologic condition in the canine uterus and recognized as a common cause of illness and death in this species. The underlying cause and pathogenic mechanism responsible for this condition remains incompletely understood. Aberrant sex steroid hormone receptor expression in the uterus of dogs with CEH has been documented but not explained. In the dog there is an exceptionally high, progestin induced production of insulin-like growth factor-I (IGF-I) which is now generally accepted to be one of the most important growth factors with a high mitogenic effect on the uterus. Therefore, in this study the immunohistochemical staining intensity for IGF-I was compared among the uteri of 25 adult female dogs that had developed CEH and 14 healthy dogs in comparable stages of the estrus cycle. Specific staining for IGF-I was found in the cytoplasm epithelial cells and in smooth muscle cells of endometrium and myometrium. A marked increase in specific staining intensity for IGF-I was found in the surface epithelium, glandular epithelium and in the stroma of the uteri of dogs with CEH. The increase in IGF-I specific staining intensity was most prominent in the superficial endometrial stroma. Based on the known role of IGF-I in endometrial proliferation, it was concluded from the present study that high concentrations of IGF-I located in and around the epithelial cells of the endometrium in dogs with CEH, could play an important role in the development of CEH.     

Ultrastructural changes in the connective tissue of the gastric region during the metamorphosis of Xenopus laevis

Development of the gastric connective tissue of Xenopus laevis during metamorphosis was investigated by electron microscopy. Throughout the larval period to stage 60, the layer of connective tissue underlying the gastric epithelium consists of immature fibroblasts surrounded by a sparse extracellular matrix. At the beginning of the transition from the larval to the adult epithelial form, at about stage 60, extensive changes occur in the connective tissue. The number of cells suddenly increses and different cell types appear. Numerous contacts between epithelial and connective tissue cells are established through random gaps in the thickened basal lamina. During stages 62–63, just after the beginning of the morphogenesis of adult-type glands, the basal lamina lining the glandular epithelium becomes thinner, and the number of contacts decreases rapidly except near the tips of the glands. After the glandular cells begin to produce zymogen granules at stage 64, contacts become rare. From stage 63, when the muscularis mucosae develops, until the completion of metamorphosis, the connective tissue consists mainly of typical fibroblasts. Outside the muscularis mucosae, the fibroblasts of the lamina propria are aligned in parallel with the curvature of the glands. These observations indicate that developmental changes in the connective tissue are closely related spatiotemporally to those of the epithelial transition from larval to adult form during metamorphic climax. Although some changes are similar to those in the intestine (Ishizuya-Oka and Shimozawa, '87b), others are specific to the gastric region, which suggests that connective tissue may have a role in organ-specific differentiation of the gastric epithelium.     

Immunohistological localization of human endometrial secretory protein, 'pregnancy-associated endometrial alpha 2-globulin' (alpha 2-PEG), during the menstrual cycle

The distribution of alpha 2-PEG, a human analogue of beta-lactoglobulin, in endometrium at different phases of the cycle was determined using immunohistochemistry with monoclonal and polyclonal antibodies. In the epithelial cells of glands in the functional zone of the endometrium, alpha 2-PEG was first detectable from Days 19 to 21 during the mid-luteal phase and maximal immunostaining was observed during the end of the late luteal phase. Intense staining in the glandular secretions and weaker staining in surface luminal epithelial cells during this period were observed. A minor population of basal glands contained alpha 2-PEG during the follicular phase. These results suggest that alpha 2-PEG synthesis by the glandular epithelium of the regenerated endometrium is hormonally regulated. Maximal staining occurring during the late luteal phase suggests that regulation may be related to the hormonal requirement for pre-decidualization rather than that required for histologically defined glandular epithelial secretion.     

Reproduction in the vervet monkey (Cercopithecus aethiops): III. The menstrual cycle

The menstrual cycles of 17 multiparous vervet monkeys were studied. Based on estradiol, progesterone, and LH profiles, ovulation is predicted to occur on day 13 of the 32.4-day menstrual cycle. Estradiol peaked on the day preceding the LH peak in 75% of cycles. Average luteal phase length (progesterone greater than 4 nmol/l) was 18 days, with progesterone rising above 4 nmol/l on the day of the LH peak. Vaginal cytology and perianal skin coloration exhibited too much within- and among-animal variability to be reliable indicators of menstrual cycle stages. Uterine biopsies of the proliferative phase were characterized by mild pseudostratification of the columnar epithelium and absence of glandular secretion; in contrast, those of the luteal phase had marked pseudostratification of the tall columnar epithelium with glandular secretions in the lumen. A few follicular-phase samples contained structures such as tortuous uterine glands with secretions. Such structures are more characteristic of the luteal phase. It is suggested that their presence can be explained by incomplete sloughing of the endometrium at menstruation, as this is known to be light or convert in this species.     

Immunocytochemical localization and messenger ribonucleic acid levels of a progesterone-dependent endometrial secretory protein (cathepsin L) in the pregnant cat uterus.

The purpose of this study was to localize immunocytochemically a progesterone-dependent protein (PDP) and to determine PDP mRNA levels during the initial stage of the implantation period. Uterine tissue was collected from Day 0-18 postcoital animals. The tissue was processed for immunocytochemical localization of PDP, and the endometrial RNA was isolated and analyzed for PDP gene expression by slot-blot hybridization. PDP was detected immunocytochemically as early as Day 5 postcoitus in the epithelial cells of the deep uterine glands, and the intensity of immunostaining appeared to peak by Day 12 postcoitus. PDP was absent in the endometrium obtained from implantation sites after Day 16 postcoitus, but the synthesis of PDP was maintained in the endometrium obtained from nonimplantation sites. Immunogold electron microscopy demonstrated that PDP was present in electron-dense granules of the glandular epithelial cells. PDP mRNA was detectable in the endometrium at Day 5 postcoitus and peaked around Day 10 postcoitus. PDP mRNA was absent in the endometrium from implantation sites after Day 16 postcoitus, but was maintained in the endometrium from nonimplantation sites. In summary, the results of this study illustrate that PDP is synthesized within the epithelial cells of the deep uterine glands, packaged within membrane-bound secretory granules, and released into the uterine lumen. Also, the process of implantation alters the gene expression in a very localized way since PDP mRNA and PDP-positive granules were absent in the endometrial glands obtained from the implantation site within 1-2 days of the onset of implantation, whereas both PDP mRNA and PDP-positive granules were maintained in the endometrial glands from nonimplantation-site regions.(ABSTRACT TRUNCATED AT 250 WORDS)     

Human endometrial cells grown on an extracellular matrix form simple columnar epithelia and glands

Summary Normal human endometrial cells were grown on an extracellular matrix containing type IV collagen, laminin, heparan sulfate proteoglycan, and entactin (Matrigel). On the extracellular matrix, dispersed endometrial cells remained rounded, and aggregated to form mounds of cells, which continued to grow in this arrangement. At 10 d, light microscopy demonstrated that these mounds were comprised of an eosinophilic substance, containing individual fusiform stromal cells. About 50% of the mounds were covered with a single layer of polarized cuboidal to columnar cells with basal nuclei, whereas 60% contained columnar cells forming glandular structures with open lumina. These polarized cuboidal and columnar cells were epithelial, based on their positive staining for cytokeratins and the possession of microvilli, tonofilaments, abundant glycogen, ribosomes, and primitive junctional complexes. Kreyberg's stain showed the presence of mucin within the lumina of the glands, indicating that they were functional. Thus, human endometrial cells grown on an extracellular matrix form a simple cuboidal to columnar epithelium, a stromal component, and glandular structures, thereby mimicking the in vivo morphology of the endometrium. This work was supported by grants ES02774, ES01247 and ES07026 (an NIEHS Toxicology Training Grant awarded to T.W for doctoral studies), from the National Institutes of Health, Bethesda, MD. Portions of this work were presented at the 1988 meetings of the Society for the Study of Reproduction in Seattle, Washington, and the Eleventh Rochester Trophoblast Conference.     

Structural and ultrastructural features of boar bulbourethral glands

The morphological features of boar bulbourethral glands were examined by light and transmission microscopy. Bulbourethral glands are compound tubuloalveolar glands surrounded by a capsule of dense connective tissue and arranged in multiple lobules formed by endpieces and excretory ducts. Endpieces and excretory ducts are both lined by a single epithelium of mucous cells with a basal nucleus. Epithelial cells accumulate secretory granules containing neutral and carboxylated acid mucosubstances and a small amount of sulphated acid mucosubstances. The ultrastructure of epithelial cells varies according to the secretory cycle. In initial stages, the cells show a columnar shape and secretory granules unevenly distributed in the cytoplasm. As the synthesis of mucosubstances progresses, the amount of the secretory granules increases and the cellular shape becomes pyramidal. Secretory granules can contain inclusions and present differences among them according to their different phases of formation. In pyramidal cells, secretory products are released into the lumen by a merocrine mechanism.     

A histological and ultrastructural comparison of the male accessory reproductive glands of diapausing and non-diapausing adults in Bruchidius atrolineatus (Pic) (Coleoptera : Bruchidae)

Cytological variations of the median and the 2 lateral accessory glands of Bruchidius atrolineatus Pic (Coleoptera : Bruchidae) were examined as a function of age and the reproduction of the male. In sexually active virgin males, the secretory epithelium is columnar at emergence, but progressively flattens, and the secretions formed and stored by its cells are expelled by exocytosis into the glandular lumen. After 10 days, the male accessory glands exhibit a stage of repletion, characteristic of glands temporarily storing their secretions in their lumen. In diapausing males, the genital tract is relatively undeveloped and the accessory glands are reduced to tubules, whose lumen, surrounded by an epithelium composed of narrow cells, contains little secreted material. The presence of secretion aggregates in the secretory epithelial cells, the abundance of rough endoplasmic reticulum in them, and the release of a part of their secretions into the glandular lumen, indicate that reproductive diapause in B. atrolineatus is characterized by a decrease in the reproductive function. and not its total arrest.     

Corrigendum to "The sow endometrium at different stages of the oestrous cycle: studies on the distribution of CD2, CD4, CD8 and MHC class II expressing" cells. [Anim. Reprod. Sci. 68 (2001) 99-109

The aim of this study was to investigate the distribution of CD2(+), CD4(+), CD8(+) lymphocyte subpopulations and MHC class II expressing cells in the sow endometrium throughout the oestrous cycle. Fifteen crossbred multiparous sows (Swedish Landrace x Swedish Yorkshire), with an average parity number of 3.4 +/- 0.7 (mean +/- S.D.) were used. Uterine samples from the mesometrial side of both horns, taken immediately after slaughter at late dioestrus (day 17, n = 3), prooestrus (day 19, n = 3), oestrus (day 1, n = 3), early dioestrus (day 4, n = 3) and dioestrus (days 11-12, n = 3), were stored in a freezer at -70 degrees C until analysed by immunohistochemistry with an avidin-biotin peroxidase method using monoclonal antibodies to lymphocyte subpopulations and MHC class II molecules. The surface and glandular epithelium as well as connective tissue layers in subepithelial and glandular areas were examined by light microscopy. For the T lymphocyte subpopulations, all oestrous cycle stages and different tissue layers taken together, the most commonly observed cell type was CD2(+) cells. The largest number of CD2(+) cells within the surface and glandular epithelium were observed at oestrus and early dioestrus. In the surface epithelium, a larger number of CD8(+) cells compared with CD4(+) cells were observed and no CD4(+) cells were found within the glandular epithelium at any stage of the oestrous cycle. In the subepithelial and glandular connective tissue layers, during the oestrus cycle stages, a larger number of CD4(+) cells compared with CD8(+) cells were found. Endothelial cells in the connective tissue generally expressed MHC class II. However, no obvious differences between oestrous cycle stages were observed. For other cells than endothelial cells, the result was as follows. In the surface epithelium, a large number of MHC class II expressing cells was observed at oestrus compared with the other stages. No MHC class II expressing cells were found at late dioestrus and dioestrus. MHC class II expressing cells were also found in the glandular epithelium, and in the subepithelial and glandular connective tissue layers during all oestrous cycle stages but with no significant differences between stages. In conclusion, the present study showed a variation in the distribution of T lymphocyte subpopulations (CD2(+), CD4(+) and CD8(+)) and MHC class II expressing cells in the sow endometrium during different stages of the oestrous cycle. Also a variation between different tissue layers was found. It is suggested that helper and cytotoxic function of the immune system have primary locations in different tissue layers of the endometrium.     

The effects of adrenalectomy on the harderian gland of the Wistar albino rats

Harderian glands of the Wistar albino rats normal and adrenalectomized were investigated by light microscopy. In normal, these glands have a tubuloalveolar structure. The gland is located in the medio posterior aspect of the orbit. It is lobulated and appears homogeneous in colour and texture. Harderian gland consist of tubules with wide lumina lined by a single layer of columnar epithelial cells surrounded by myoepithelial cells within their basal lamina. It contains porphyrin pigment which is stored as solid intraluminal deposits. The glandular epithelium possesses two cell types, termed A and B. Type A cells are more numerous. The single excretory duct of the gland is directly continuous with endpieces at the hilus and opens nasally and ventrally to the third eyelid. The excretory duct is accompanied by many acini of small serous glands around it. The tubuloalveoli of the gland is not divided into lobules. There is no branched duct system within the gland. The secretion seems to be associated with porphyrins, is essentially released by exocytosis, but holocrine secretion also occurs. The single excretory duct is lined by a stratified epithelium. The gland is surrounded by a collagenous capsule. The adrenalectomy, caused degenerative changes in the glands. Epithelial height was lower than in normal gland epithelium. Most of the acini were completely disorganised. The acinar lumina were filled with porphyrin debris. The results suggest that rat harderian glands are sensitive to adrenal androgen changes in both male and female rats.     

The sow endometrium at different stages of the oestrous cycle: studies on the distribution of CD2, CD4, CD8 and MHC class II expressing cells

The aim of this study was to investigate the distribution of CD2+, CD4+, CD8+ lymphocyte subpopulations and MHC class II expressing cells in the sow endometrium throughout the oestrous cycle. Fifteen crossbred multiparous sows (Swedish Landrace x Swedish Yorkshire), with an average parity number of 3.4+/-0.7 (mean+/-S.D.) were used. Uterine samples from the mesometrial side of both horns, taken immediately after slaughter at late dioestrus (day 17, n=3), prooestrus (day 19, n=3), oestrus (day 1, n=3), early dioestrus (day 4, n=3) and dioestrus (days 11-12, n=3), were stored in a freezer at -70 degrees C until analysed by immunohistochemistry with an avidin-biotin peroxidase method using monoclonal antibodies to lymphocyte subpopulations and MHC class II molecules. The surface and glandular epithelium as well as connective tissue layers in subepithelial and glandular areas were examined by light microscopy.For the T lymphocyte subpopulations, all oestrous cycle stages and different tissue layers taken together, the most commonly observed cell type was CD2+ cells. The largest number of CD2+ cells within the surface and glandular epithelium were observed at oestrus and early dioestrus. In the surface epithelium, a larger number of CD8+ cells compared with CD4+ cells were observed and no CD4+ cells were found within the glandular epithelium at any stage of the oestrous cycle.In the subepithelial and glandular connective tissue layers, during the oestrus cycle stages, a larger number of CD4+ cells compared with CD8+ cells were found.Endothelial cells in the connective tissue generally expressed MHC class II. However, no obvious differences between oestrous cycle stages were observed. For other cells than endothelial cells, the result was as follows. In the surface epithelium, a large number of MHC class II expressing cells was observed at oestrus compared with the other stages. No MHC class II expressing cells were found at late dioestrus and dioestrus. MHC class II expressing cells were also found in the glandular epithelium, and in the subepithelial and glandular connective tissue layers during all oestrous cycle stages but with no significant differences between stages.In conclusion, the present study showed a variation in the distribution of T lymphocyte subpopulations (CD2+, CD4+ and CD8+) and MHC class II expressing cells in the sow endometrium during different stages of the oestrous cycle. Also a variation between different tissue layers was found. It is suggested that helper and cytotoxic function of the immune system have primary locations in different tissue layers of the endometrium.     

Morphology and ultrastructure of the esophagus during the ontogeny of the spider crab Maja brachydactyla (Decapoda,Brachyura, Majidae)

The esophagus of the eucrustaceans is known as a short tube that connects the mouth with the stomach but has generally received little attention by the carcinologists, especially during the larval stages. By this reason, the present study is focused on the morphology and ultrastructure of the esophagus in the brachyuran Maja brachydactyla during the larval development and adult stage. The esophagus shows internally four longitudinal folds. The simple columnar epithelium is covered by a thick cuticle. The epithelial cells of the adults are intensively interdigitated and show abundant apical mitochondria and bundles of filamentous structures. The cuticle surface has microspines and mutually exclusive pores. Three muscle layers surrounded by the connective tissue are reported: circular muscles forming a broad continuous band, longitudinal muscle bundles adjacent to the circular muscles, and dilator muscles crossing the connective tissue vertically toward the epithelium. The connective tissue has rosette glands. The esophagus of the larvae have epithelial cells with big vesicles but poorly developed interdigitations and filamentous structures, the cuticle is formed by a procuticle without differentiated exocuticle and endocuticle, the connective layer is thin and the rosette glands are absent. The observed features can be explained by his role in the swallowing of the food.     

Flow cytometric analysis and sorting of human endometrial cells after immunocytochemical labeling for cytokeratin using a monoclonal antibody

Endometrial cells in suspension were stained with propidium iodide and a monoclonal antibody against a cytokeratin intermediate filament protein specific for glandular and columnar cells (RGE 53). In this way columnar epithelial cells of the normal endometrium and of adenocarcinomas can be distinguished and separated by flow cytometry from non-epithelial cells (fibroblasts and inflammatory cells) and squamous epithelial cells, all of which are negative for RGE 53. This makes it possible to analyse and also sort pure fractions of this particular tissue type for further studies. The use of propidium iodide allows simultaneous DNA flow cytometry of these columnar epithelial cells. Therefore, the use of antibodies to cytokeratin in combination with propidium iodide can be of help in analyzing and sorting pure fractions of both normal and malignant cells. This allows a more refined examination of complex cell mixtures using flow cytometry.     

The uterovaginal sperm host glands of the quail (Coturnix coturnix japonica)

Summary Ultrastructural and ultrahistochemical studies were performed on the uterovaginal sperm host glands of the quail (Coturnix coturnix japonica). The proximal parts of the glandular necks are lined by a pseudostratified epithelium, consisting of high columnar ciliated cells and small, irregular shaped, basal cells.The true glandular epithelium is composed only of columnar cells with microvilli on their luminal end. A characteristic luminal feature is a large lipid droplet in the perinuclear region. In the subplasmalemmal region numerous tubular profiles are seen which could represent a cellular resorption system.To evaluate the absorptive capacity of the Uterovaginal sperm host glands, tracer studies with HRP, ferritin, lanthanum and ruthenium red were undertaken. Since between 5 min and 3 h after injection no absorption could be found with the techniques mentioned, it is suggested that phagocytosis of spermatozoa by the glandular epithelium is not likely to occur.     

The sow endometrium at different stages of the oestrous cycle: studies on morphological changes and infiltration by cells of the immune system

The aim of this study was to investigate the distribution of leukocytes and the morphological changes of the sow endometrium throughout the oestrous cycle. Fifteen crossbred multiparous sows (Swedish Landrace x Swedish Yorkshire), with an average parity number of 3.4 +/- 0.7 (mean +/- S.D.) were used. Blood samples were collected from the jugular vein 1h before slaughter for analyses of oestradiol-17beta and progesterone levels. Uterine samples from the mesometrial side of both horns, taken immediately after slaughter at late dioestrus, prooestrus, oestrus, early dioestrus and dioestrus, were fixed, embedded in plastic resin and stained with toluidine blue. The surface and glandular epithelium as well as subepithelial and glandular connective tissue layers were examined by light microscopy.The significantly highest surface and the glandular epithelium were observed at oestrus and dioestrus, respectively.The largest number of capillaries (underneath the surface epithelium) was found at oestrus. In the surface epithelium, the largest number of intraepithelial lymphocytes (IELs, round nucleus) was found at early dioestrus. The largest number of lymphocytes and macrophages within the glandular epithelium were found at early dioestrus and oestrus, respectively.In the subepithelial connective tissue layer, the most common type of leukocytes during all stages was the lymphocyte. The largest numbers of lymphocytes and neutrophils were found at oestrus while the largest number of eosinophils was found at dioestrus.The dominating cells of the immune system in the connective tissue of the glandular layer were lymphocytes and macrophages. The significantly largest numbers of lymphocytes and plasma cells were found at early dioestrus and dioestrus, respectively.The number of lymphocytes in the connective tissue of the glandular layer and the number of plasma cells in the subepithelial layer were positively correlated with the plasma level of progesterone (P < or = 0.05). The numbers of capillaries and neutrophils in the subepithelial layer underneath the surface epithelium as well as the number of macrophages in both surface and glandular epithelium were positively correlated with the plasma level of oestradiol-17beta (P < or = 0.05).In conclusion, the present study showed a variation in the infiltration and distribution of lymphocytes, neutrophils, eosinophils, macrophages, mast cells and plasma cells in the sow endometrium during different stages of the oestrous cycle. Also morphological parameters (e.g. height of surface and glandular epithelium, capillaries density and degree of oedema) varied throughout the oestrous cycle.     

Corrigendum to "The sow endometrium at different stages of the oestrus cycle: studies on morphological changes and infiltration by cells of the immune system." [Anim. Reprod. Sci. 65 (2001) 95-114

The aim of this study was to investigate the distribution of leukocytes and the morphological changes of the sow endometrium throughout the oestrous cycle. Fifteen crossbred multiparous sows (Swedish Landrace x Swedish Yorkshire), with an average parity number of 3.4+/-0.7 (mean+/-S.D.) were used. Blood samples were collected from the jugular vein 1 h before slaughter for analyses of oestradiol-17beta and progesterone levels. Uterine samples from the mesometrial side of both horns, taken immediately after slaughter at late dioestrus, prooestrus, oestrus, early dioestrus and dioestrus, were fixed, embedded in plastic resin and stained with toluidine blue. The surface and glandular epithelium as well as subepithelial and glandular connective tissue layers were examined by light microscopy (LM). The significantly highest surface and the glandular epithelium were observed at oestrus and dioestrus, respectively. The largest number of capillaries (underneath the surface epithelium) was found at oestrus. In the surface epithelium, the largest number of intraepithelial lymphocytes (IELs, round nucleus) was found at early dioestrus. The largest number of lymphocytes and macrophages within the glandular epithelium were found at early dioestrus and oestrus, respectively. In the subepithelial connective tissue layer, the most common type of leukocytes during all stages was the lymphocyte. The largest numbers of lymphocytes and neutrophils were found at oestrus while the largest number of eosinophils was found at dioestrus. The dominating cells of the immune system in the connective tissue of the glandular layer were lymphocytes and macrophages. The significantly largest numbers of lymphocytes and plasma cells were found at early dioestrus and dioestrus, respectively. The number of lymphocytes in the connective tissue of the glandular layer and the number of plasma cells in the subepithelial layer were positively correlated with the plasma level of progesterone (P < or = 0.05). The numbers of capillaries and neutrophils in the subepithelial layer underneath the surface epithelium as well as the number of macrophages in both surface and glandular epithelium were positively correlated with the plasma level of oestradiol-17beta (P < or = 0.05). In conclusion, the present study showed a variation om the infiltration and distrobution of lymphocytes, neutrophils, eosinophils, macrophages, mast cells, and plasma cells in the sow endometrium during different stages of the oestrous cycle. Also morphological parameters (e.g. height of surface and glandular epithelium, capillaries density and degree of oedema) varied throughout the oestrous cycle.     

Genome multiplication in the trophoblasts and glandular epithelium of endometrium during embryo implantation and placentation of silver fox

Dynamics of genome multiplication during establishment of interrelations between the trophoblast and the glandular epithelium of endometrium was studied in the course of placenta formation in the silver fox. Endometrium response on the embryo implantation exhibits some features of inflammation. In the course of placenta formation the trophoblast gains access to the endometrial glandular epithelium zone, while the endometrial blood vessels grow the other way into the expanding trophoblast zone. The trophoblast gradually replaces the whole epithelium and part of the stroma of the endometrium, closely adjoining the endometrial vessels but not disrupting them. Cytophometric DNA measurements in the trophoblast nuclei have shown that most of the nuclei are polyploid: predominantly 4c-64c, occasionally 128c and 256c. Polyploidy of the trophoblast may result from various types of polyploidizing mitoses. Cytophotometric DNA measurements in mitotic figures have revealed mitoses with DNA amounts equal to 4c (2n), 8c (4n), and 16c (8n), which indicates that trophoblast cells in the silver fox placenta are able to enter mitosis prior to the octaploid level. Higher degrees of polyploidy in the trophoblast cells may be achieved presumably by endoreduplication. In the silver fox polyploidization of uterine grandular epithelial cells during placentation occurs until the level of 8c. Thus, the tissue-specific response of the uterus to the implanting embryo is an active proliferation and polyploidization of the glandular epithelium, rather than formation of a population of polyploid decidual cells (i.e. connective tissue cells). Using the silver fox endotheliochorial placenta as an example, a regularity has been confirmed that cells of both maternal and fetal origin are polyploid in sites of their contact in placenta, which might be of protective significance in the contact of allogenic organisms.