الفهرس 
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Macroscopical anatomy of the ovary of domestic animalsOnly 14 pages are availabe for public view
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Abstract
Summary
In my thesis, 87 bovine ovaries were investigated using conventional light microscopy, glycohistochemical and immunohistochemical methods.The animals were divided into three age groups (10 - 44 months, 48 - 84 months, 85 - 132 months). Carbohydrate structures were examined using 14 FITC-conjugated or biotin labelled plant lectins:
Immunohistochemical studies were performed using 13 different antibodies against the following proteins: cytokeratins (CKs) 5, 8, 14, 18, 19, vimentin, -smooth muscle actin (SMA), desmin, tubulin, laminin, S-100 protein, progesterone receptor (PR) and estrogen receptor (ER). The morphological and histochemcial features of the ovarian surface epithelium, follicles (healthy and atretic follicles) the rete ovarii and interstitial glands have been described.
My observation on gross morphology of the ovary showed that ovaries from different age groups showed a higher frequency of ovulation on the right side, estimated by the greater number of corpora lutea on this side.
Morphology and characterization of the ovarian surface epithelium (OSE):
The bovine ovary is covered by a single layer of epithelial cells that vary in shape from simple squamous to cuboidal. In certain areas also a low pseudostratified columnar or columnar epithelium can be observed. Within the epithelium two types of cells (light and dark cells) can be discerned. The epithelial cells demonstrated positive immunostaining in the cytoplasm for the intermediate filaments CK5, CK8, CK14, CK18, CK19, which are markers for epithelial cells, for S100 protein, tubulin, laminin, and desmin. No immunostaining was observed for vimentin, a marker of fibroblasts. The surface epithelial cells demonstrated nuclear and cytoplasmic staining for PR and ER . The underlying stroma cells were positive for vimentin, tubulin, SMA, ER, PR and S-100 protein. A few cells were positive for desmin and laminin.
Using glycohistochemistry I could demonstrate that the basement membrane of the surface epithelium and also intracellular granules within the epithelium reacted strongly positive with wheat germ agglutinin and weak with the succinylated form of this lectin. Many other lectins like conacavalin A, viscum album agglutinin,, peanut agglutinin, phaseolus vulgaris leuco- and erythro-agglutinin, maackia amurensis agglutinin and sambuccus nigra agglutinin only stained the cytoplasm of the epithelium. The intensity of the staining was generally stonger in the ovary of younger cows compared to older ones.
Morphology and charcterization of the bovine rete ovarii:
The rete ovarii was found in every ovary examined. This cleary demonstrates that the rete ovarii is not a vestigial embryological structure but a normal prominent epithelial structure,
regularly found also in the adult ovary. The lumen of rete tubules appeared increased in width in older cows, but the convolution seemed to be decreased in these animals. My results confirmed and extended the results from previous studies in the cow. I could clearly show that the bovine rete system consists of three main parts, the intra-ovarian rete (IR), the connecting rete (CR), and the extra-ovarian rete (ER). The CR can be further subdivided into that portion, which lies within the ovary proper (oCR) and a portion that lies in the mesovarium (mCR). The connecting rete ovarii and extraovarian rete display a connection with the uterine tube and establish a passage way to the surface of the ovary. The different parts of the rete ovarii can only be recognized by careful examination of longitudinally serial sections, which permits an accurate visualization of its different portions. The cells of the intraovarian rete contain single to multiple layers of columnar cells, whereas those in the connecting rete are pseudostratified or stratified columnar. The cells lining the extraovarian rete are cuboidal and are single to multilayered. In most regions, the rete epithelium rests on a distinct basal lamina. Interesting findings have been some areas without a basement membrane, especially in those areas where some distinctive cell masses were branching out from rete tubules. This was clearly seen in parts of the connecting and intraovarian rete ovarii.
The width of the lumina, the type of epithelium lining, the number and the convlution of the tubules vary in different parts of rete ovarii. An especially interesting finding was that the rete ovarii had an open connection with the infudibulum of the uterine tube. Also, a connection between connecting rete tubules and infundibulum was obsereved, allowing the passage of secretory material from the rete ovarii to the uterine tube. Although it needs more studies to evaluate the significance of this connection, the transported secretory material may contribute to the fertilization process, which takes place in the infundibulum.
The epithelium of the rete was clearly immunostained with antibodies against CK5, CK14, CK18 and CK19, but CK8 was consistently negative in any part of rete ovarii tubules. Additionally, the rete ovarii shows cytoplasmic immunostaining with antibodes against vimentin, tubulin and S-100 protein. ER α and PR expression could be localized in the nucleus and in the cytoplasm of rete epithelial cells. The staining intensity of PR was usually stronger than that of ER α.
The immunostaining with SMA showed that multiple layers of smooth muscle cells surrounded the intraovarian rete and the connecting rete ovarii inside the ovary. In other parts of rete ovarii (mesovarium, connecting rete and extraovarian rete), no smooth muscle cells appear around the epithelium. The stroma surrounding the rete epithelium shows a positive reaction to desmin, around the intraovarian rete. Also, a few cells were positive for laminin. A distinct number of stroma cells around the rete ovarii showed receptors for SMA.
In in rete ovarii, a lectin-binding in the basement membrane was observed with wheat germ agglutinin, as well as its succinylated lectin form and maackia amurensis agglutinin.
An interesting lectin staining was found in the basement membrane of connecting rete ovarii, which was different from other parts of rete ovarii. Positive staining was observed with maackia amurensis agglutinin, sambuccus nigra agglutinin and succinylated wheat germ agglutinin. Wheat germ agglutinin and conacavalin A strongly stained some basally cells located within the retial epithelium of connecting rete. I assume that these cells with special carbohydrate characteristics may be stem cells for the regeneration of the rete epithelium.
Morphology and characterization of bovine ovarian follicles:
My glycohistochemical results show that the different classes of ovarian follicles (primordial, primary, secondary and antral follicles) and display a distinct distribution pattern for the binding of several lectins. These results obtained from normal bovine ovaries may form a sound basis for future studies concerning changes in lectin staining occurring in different diseases of the ovary. Immunohistochemical investigations demonstrated that follicle development from primordial to antral follicles is associated with a decrease in cytokeratins, vimentin, S-100 protein and tubulin immunostaining. A remarkable finding is the apperanace of numerous vimentin-positive cytoplasmic projections from the corona radiata cells that penetrate the zona pelluida and make contact with the oocyte. Oocyte and cumulus cells are also positive for S-100 proteins. During follicle development, expression of ER in the granulosa cells as well as in the theca cells gradually decreased. PR immunostaining in the granulosa cells appear to increase during follicle development.
During follicular atresia the most remarkable feature was the distinct increase in CK immunostaining in the granulosa cells and the appearance of elongated, intermediate filament containing granulosa cells. In addition, a positive reaction with antibodies against SMA was observed in the theca interna and theca externa cells. A strong reaction for laminin was consistently found in the basement membrane of degenerating follicles. The oocyte of atretic follicles stained stronger with antibodies to S-100 protein compared to healthy ones. ERα immunostaining was observed as strong granular reaction in the nuclei of cells of the theca of atretic follicles. The immunostaining for PR of granulosa and theca cells in atretic follicles appeared also generally stronger than that of healthy follicles.
Morphology and characterization of bovine interstitial gland cells:
Interstitial gland cells are groups of epitheloid cells, which are located in the the ovarian cortex and medulla, at the hilus of the ovary and which are associated with all parts of the rete ovarii. Their cells possess a large vesicular nucleus and a pale foamy eosinophilic cytoplasm. Interstitial glands originate from the luteinization of theca interna cells of atretic follicles or from hypertrophied granulosa cells of atretic preantral follicles. They obviously
also arise from the rete ovarii. Interstitial glands are not transitory structures and are not only correlated with degenerative processes of follicles.
My study supports the hypothesis that many interstitial glands of the ovary arise from the rete, which seem to be an important source of the interstitial glands. The secertory material of the interstitial glands seems to contain glycoproteins, which distinctly stained with PAS. Additionally the interstitial glands gave a positive cytoplasmic immunostaining with antibodies to cytokeratins, vimentin, tubulin, ER and PR. Laminin is present in their basement membrane.