Submicroscopic changes in the luminal cells of the endometrium in cows during the estrus cycle

The structure of luminal epithelium cells in the endometrium of a cow shows little variation during the sexual cycle. Various coarse and irregular microvilli are produced on the surface of cells in pro-oestrus and oestrus. Starting from pro-oestrus, the relative volume of mitochondria increases to culminate in met-oestrus and di-oestrus. Their highest number was observed in oestrus; in met-oestrus they enlarge and many of them gradually disintegrate during di-oestrus. The maximum development of granular endoplasmic reticulum was observed in oestrus. The quantitative proportion of smooth membranes is small and their volume and surface area increase from the lowest values in di-oestrus up to culmination in oestrus. The highest number of lysosomes was observed at the end of sexual cycle and in pro-oestrus. In oestrus and met-oestrus the apical parts of cytoplasm contain many smooth-walled vesicles and cisterns.     

Submicroscopic changes in the secretory cells of the epithelium of the bovine oviduct during the estrous cycle

The secretory cells of the ampullar part of bovine oviduct are characterized by the secretory granules in cytoplasm. Their apical surface is covered with a small amount of micro-villi. Among the organellae, the Golgi apparatus is well-marked: during the sexual cycle it produces several centres. Its volume and surface reach their maxima before ovulation. The mitochondria are large and have a smaller amount of cristae. Their number culminates in pro-oestrus and their volume and surface area in metoestrus. The tubuli of granulated endoplasmic reticulum dilate during pro-oestrus and oestrus and some of them later disintegrate. They reach the largest volume and surface in pro-oestrus when the highest number of polyribosomes also occurs. Secretory granules are produced throughout the cycle as low-density spherical corpuscles covered with a simple membrane: in the course of maturation they change into high-density corpuscles and some of them break down. Their number and volume culminate in metoestrus when they are secreted on a mass scale. The population of secretory cells is heterogeneous. Besides dense and light cells, thin granules. Some cells lose contact with the basal membrane and their extrusion occurs mainly during metoestrus.     

Studies on improving the fertility of aged sows. 2. Results of histological studies on the structure of the endometrium in aged sows during estrous cycle]

Histomorphological and histometric techniques were employed to study cyclic processes in the endometrium. Specimens of uterus were obtained on the 1st, 5th, 8th, 13th, 17th and 21st days of the cycle. The effect of oestrogens, which are produced in large amounts during pro-oestrus, oestrus and to some extent in metoestrus, was reflected in proliferative processes in the epithelium, with increases in the cell population, thickness of the epithelium, and height of the superficial and glandular epithelium. During oestrus the subepithelial layer was broad and was rich in lymphocytes and neutrophile grandulocytes, while the lamina propria showed considerable oedema and hyperaemia. The action of gestagens during dioestrus led to an increase in glandular structures due to the development of more convolutions and a more even distribution of glands throughout the entire propria. There was evidence of active glandular secretion, which during the course of dioestrus resulted in a relatively low and single-layered superficial and glandular epithelium.     

Submicroscopic changes in ciliated cells of the epithelium of the oviduct in cows during the estrus cycle

The submicroscopic changes in the ciliary cells of the ampullar part of oviduct are of qualitative as well as quantitative nature. The mitochondria are mainly located in the supranuclear region. They are small, having densely arranged lamelliform cristae and dense matrix. They have the largest volume in metoestrus and the highest number and the largest surface already during oestrus. The volume and surface of granular endoplasmic reticulum culminates already during pro-oestrus. The reticulum occurs mainly over the nucleus where it produces tubuli densely covered with ribosomes which begin to dilate already during pro-oestrus. The Golgi apparatus and the membranes of smooth reticulum are poorly developed and their quantitative changes during the cycle are not significant. Various forms of lysosomes, whose volume reaches its maximum in dioestrus and during pro-oestrus, constitute a constant component of cytoplasm. Secretory granules occur only rarely in these cells. Kinocilia grow from the basal corpuscles and are more frequent on cells with a light cytoplasm. Higher-density cells have more micro-villi between kinocilia. Deciliation with the disintegration of membrane, filaments and often also the basal corpuscles is observed during metoestrus and at the beginning of dioestrus. Reciliation begins with the formation of basal corpuscles and their replication at the end of dioestrus and in pro-oestrus. The frequency of ciliary regeneration is comparatively small.     

Changes in the morphology of nuclei in the oviduct epithelium of the cow during the estrous cycle

The changes in the structure of nuclei and nucleoli are good markers of the changes in the activity of epithelium cells of oviducts in cows during the sexual cycle. They are manifested by the changes in the proportion of condensed chromatin and interchromatin. In the secretory as well as ciliary cells, the maximum proportion of interchromatin is recorded in pro-oestrus and oestrus, whereas in metoestrus it is the proportion of condensed chromatin that increases. Metoestrus is characterized by the segregation of nucleoli and by the formation of ring-like nucleoli which partially persist also in dioestrus and in some cells throughout the cycle. Invaginations of the nuclear membrane (which are levelled off later) occur on many nuclei at the end of metoestrus and in dioestrus. Single nuclear bodies occur in the nuclei and the frequency of the the occurrence of interchromatin granules changes. Dilation of perinuclear spaces can be observed in the secretory cells, mainly in the period of oestrus.     

Microscopic structure of the uterine mucosa in cows during the estrus cycle

The endometrium of a cow shows little variation during the sexual cycle. Proliferation starts by increasing the relative volume of the connective-tissue layer of mucous membrane at the onset of pro-oestrus and culminates during oestrus. The volume of luminal epithelium increases more slowly from the lowest values in di-oestrus, the maximum level being obtained in met-oestrus. The volume of glandular epithelium is greatest in met-oestrus and at the start of di-oestrus; during pro-oestrus it is low but increases rapidly afterwards. The nuclei of luminal and gland cells are located basally and are shifted towards the centre of cells in the period of secretory activity. The nucleocytoplasmic ratio of epithelium cells is at its maximum during pro-oestrus and decreases in the subsequent stages. The intensity of PAS reaction also increases at the onset of pro-oestrus, the maximum being obtained in met-oestrus, to persist also in di-oestrus in some cells. Lipid droplets occur, on a larger scale, in gland cells, and the frequency of their occurrence increases in met-oestrus and di-oestrus.     

ASSESSMENT OF VAGINAL IMPEDANCE MEASUREMENTS AS AN INDICATOR OF OESTRUS IN CATTLE

A study was made in cattle of the variation of vaginal impedance with respect to the placement of probe, time after insertion, and stages of the oestrous cycle. Impedance values were lowest and least variable when determined in the ventral sector of the vaginal fornix. Allowing the probe time to warm up improved results.
Vaginal impedance declined by approximately 30% during pro-oestrus, oestrus and metoestrus when compared with dioestrus. The time at which the lowest values were reached varied between animals, in 2 cases being a day before oestrus, in another 2 on the day of oestrus, and for 1, the day after oestrus. The method described was not suitable for determining the peak of behavioural oestrus.     

动情周期小鼠输卵管壶腹黏膜中nNOS的表达与活性

应用免疫组织化学 SP法和计算机图象分析法研究神经元型一氧化氮合酶 ( neuronalnitric oxide synthase,n NOS)在动情周期小鼠输卵管壶腹部黏膜的表达与活性。3 -硝基酪氨酸( 3 -nitrotyrosine,3 -NT)是一氧化氮 ( nitric ox-ide,NO)的标志分子 ,用其显示 n NOS的活性。n NOS在育龄小鼠输卵管壶腹部黏膜内的表达具有鲜明的周期性特征。在间情期 ,黏膜中的n NOS阳性细胞较少 ,阳性强度也较低 ;从发情前期到发情后期 ,n NOS阳性细胞数量明显增多 ,阳性强度也逐渐提高 ,并在发情后期达到顶峰。与此相一致 ,3 -NT在黏膜上皮中的表达强度也以发情后期最高。这提示输卵管壶腹部黏膜上皮细胞高表达具有强活性的 n NOS可能是其作为受精部位的原因之一     

Immunohistochemical Localization of the Progesterone and Oestrogen α Receptors in the Uterine Horns of the African Giant Rat (Cricetomys gambianus)

The present study investigated the immunolocalization of the progesterone and oestrogen α receptors in the uterine horns of the African giant rat during the oestrous cycle. The progesterone and oestrogen α receptors were demonstrated in various cellular constituents of the endometrium, myometrium and perimetrium. The intensity of progesterone and oestrogen α receptor immunostaining in the endometrial and myometrial layers of the uterine horns varied during the oestrous cycle. The intensity of oestrogen α receptor immunoreactivity in the luminal epithelium was high during pro‐oestrus, oestrus and dioestrus. Progesterone and oestrogen α receptor immunoreactivity in the endometrial epithelia was absent during metoestrus. Moderate to strong immunostaining for the progesterone and oestrogen α receptors was demonstrated in the myometrial smooth muscle cells during pro‐oestrus, oestrus and dioestrus. The intensity of progesterone and oestrogen α receptor immunostaining in the myometrial smooth muscle cells was low during metoestrus. Stromal cells in the perimetrium consistently expressed progesterone and oestrogen α receptor immunoreactivity throughout the oestrous cycle. The findings of the study indicate that in the giant rat the immunolocalization of the progesterone and oestrogen α receptors, in endometrial and myometrial regions of the uterine horns, varies during the oestrous cycle.     

Investigation of vaginal mucus parameters: Development of models for staging the oestrous cycle of the Bunaji cow

Changes in some vaginal mucus parameters were studied in order to generate predictive models capable of enhancing oestrous cycle staging, using equal groups (unsynchronized-USC [no treatment] and synchronized-SC [Synchromate^® i/m on d0, d11]) of Bunaji cows (n = 48) aged 3–4 years. Vaginal mucus was collected (starting d11 in SC) daily over 26 days using standard procedures. Physical (viscosity, elasticity, density, resistivity) and biochemical (pH, glucose, cholesterol, total protein, calcium, magnesium, sodium, potassium) parameters were evaluated using standard procedures. Data were analysed using chi-square and multinomial logit regression modelling. Models generated using oestrus as reference categories were ascertained for accuracies. Chi-square values for viscosity, elasticity and density were significant (p < .01) in USC and SC across stages of the cycle. Results for USC showed that pH and cholesterol were predictive (p < .01) for pro-oestrus, metoestrus and dioestrus, while total protein was predictive (p < .01) for dioestrus only. Similarly, magnesium was predictive (p < .05) for pro-oestrus. For SC, pH, magnesium and cholesterol were predictive (p < .01) for pro-oestrus, metoestrus and dioestrus, while total protein was predictive (p < .01) for pro-oestrus and dioestrus. Potassium and total protein were also predictive for metoestrus at 10% and 5% significance levels, respectively. Though findings suggest the usefulness of magnesium in staging the oestrous cycle only in synchronized cows, pH, total protein and cholesterol appeared to be the more important vaginal mucus parameters in Bunaji cows, regardless synchronization. Furthermore, the models developed showed high accuracy levels for staging the oestrous cycle in USC (100%) and SC (89%).     

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.     

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.     

Results of histochemical and biochemical studies of uterus of gilts during the estrous cycle]

Alkaline phosphatase activity as well as lipid, polysaccharide, glycogen, and acid mucopolysaccharide levels in the uteri of 79 gilts were histochemically tested during the first three sexual cycles. Intra-cyclic alkaline phosphatase activity exhibited clearly pronounced variations in the surface epithelium, with maximum values reached in metoestrus, and moderate variations in the endometrial stroma, with maximum values reached in dioestrus. Cycle-dependent variations were recordable also from the glycogen and lipid levels in the surface and glandular epithelia and from the acid mucopolysaccharide levels in the endometrial stroma. The activity of alkaline phosphatase as well as the levels of glycogen and acid mucopolysaccharides during the first cycle still were lower than those in the second and third. Biochemical examinations of the endometrium revealed significant cycle-dependent variations in the activities of alkaline phosphatase, inorganic pyrophosphatase, and succinate-dehydrogenase as well as in the concentrations of soluble protein and glycogen, with maximum values being recordable on the tenth day of cycle. No significant intracyclic variations were recordable from the activities of acid phosphatase as well as of aspartate alanine-amino transferase.     

The influence of the oestrous cycle on the intravenous glucose tolerance test in the bitch

The possibility that endogenous oestrogen and progesterone affect carbohydrate tolerance in the female dog was investigated by relating the results of repeated intravenous glucose tolerance tests to the phases of the oestrous cycle, namely anoestrus, pro-oestrus, oestrus and dioestrus. Neither the glucose tolerances nor the insulin responses were significantly different between these phases of the oestrous cycle in 12 Dalmatian bitches.     

Morphological Changes of the Endometrial Epithelium in the Bitch during Metoestrus and Anoestrus

Although cyclic changes of the endometrium in dogs involving both stromal and glandular compartments have been described, the fate of the surface epithelium after progressive growth and secretion is still unclear. In the present study, uteri of 43 healthy bitches in metoestrus and anoestrus were examined macroscopically and histologically. Tissue biopsies were taken from three different locations (cranial and middle parts of uterine horns and bifurcation). The stage of the oestrous cycle was determined by evaluation of progesterone and oestradiol levels in plasma hormone and was also confirmed clinically. Crypts formed in the luteal phase were covered with a columnar epithelium which gradually underwent fatty degeneration. In addition, the stromal part of the crypts disappeared and finally, in early anoestrus, epithelial sheaths desquamated and shed off into the uterine lumen. The surface epithelium was replaced by new cuboidal cells proliferating and migrating from the glandular openings. These findings were confirmed by oil red O staining and immunohistochemical detection of proliferation with Ki‐67 marker.     

The Immunohistochemical Localization of Desmin and Smooth Muscle Actin in the Ovary of the African Giant Rat (Cricetomys gambianus) During the Oestrous Cycle

The aim of this study was to describe the distribution of smooth muscle actin and desmin immunopositive cells in the ovary of the giant rat. In addition, the study describes the morphological changes in the ovary of this species during the oestrous cycle. Healthy secondary and tertiary follicles dominated the ovary during pro-oestrus and oestrus. The theca externa of the tertiary follicles was immunopositive for smooth muscle actin, but immunonegative for desmin. Oestrus was also characterized by the presence of corpora haemorrhagica, which had an outer layer of smooth muscle actin immunopositive cells. Differentiating corpora lutea were observed during metoestrus. A further notable feature of the ovary during metoestrus was the presence of numerous atretic secondary and tertiary follicles. In the later stages of atresia, the follicles were infiltrated by desmin and smooth muscle actin immunopositive cells. Dioestrus was characterized by the presence of non-regressing and regressing corpora lutea. Immunostaining for smooth muscle actin was demonstrated in the enclosing layer of the corpora lutea, as well as in the tunica media of blood vessels within the corpora lutea. The results of this study have shown that morphological changes in the ovary of the giant rat during the oestrus cycle are similar to those of laboratory rodents. Furthermore, the results of the immunohistochemical study indicate that the perifollicular distribution of desmin and smooth muscle actin cells changes during follicular development and atresia.     

Application of vaginal cytology and plasma Srogesterone eterminations to the management of reproduction in the bitch

The use of vaginal cytology and plasma progesterone determinations in the management of 11 bitches presented to our small animal fertility clinic are described. Nine bitches were mated or artificially inseminated and seven became pregnant. Reproductive patterns detected included failure of ovulation, prolonged pro-oestrus with late ovulation, short pro-oestrus/oestrus with early ovulation, short pro-oestrus/oestrus with late ovulation and normal pro-oestrus/oestrus with late ovulation.     

Large granular lymphocytes in the oviduct of developing and hormone-treated chickens.

1. In the present study the distribution of large granular lymphocytes (LGLs) and influence of oestrogen on these cells was investigated in the oviduct of chickens by the observation of H and E stained sections. 2. The LGLs first appeared in the oviduct at 9 weeks and their frequency of occurrence increased with age and was highest in the infundibulum and vagina from 21 to 32 weeks of age. The frequency of occurrence of LGLs from magnum to uterus (glandular part) was low. These cells were located at the base, middle and apical parts of the lining epithelium as well as in the sperm-storage glandular epithelium. 3. When chickens of 21 weeks were treated with DES, LGLs abundantly infiltrated in the oviducal epithelium in comparison to the control. 4. These results suggested that the development of LGLs in the oviduct of chickens correlates with oestrogen secretion.     

Scanning Electron Microscopic Changes of the Canine Uterine Luminal Surface during Oestrus and Late Metoestrus

In this study the endometrial morphology of four dogs in oestrus and 10 dogs in late metoestrus was investigated with scanning electron microscopy. In early oestrus the cells were slightly convex with fairly long microvilli and cell boundaries that were apparent but situated on a deeper level than the cell surface. In late oestrus the cells were clearly convex with long and numerous microvilli masking the cell boundaries. At the beginning of late metoestrus the cells became less convex with many but short microvilli and prominent but lower situated cell boundaries. At the end of late metoestrus the cells were flat with very short microvilli and protruding cell borders. These morphological findings were correlated with the cyclic variations of the steroid hormone levels.