The polycystic ovarian (PCO) condition: apoptosis and epithelialization of the ovarian antral follicles are aspects of cystogenesis in the dehydroepiandrosterone (DHEA)-treated rat model (original) (raw)
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Reproductive Biology and Endocrinology, 2009
Background: Cystic ovarian disease is an important cause of infertility that affects bovine, ovine, caprine and porcine species and even human beings. Alterations in the ovarian micro-environment of females with follicular cysts could alter the normal processes of proliferation and programmed cell death in ovarian cells. Thus, our objective was to evaluate apoptosis and proliferation in ovarian cystic follicles in rats in order to investigate the cause of cystic follicle formation and persistence.
The Anatomical Record, 1992
Immature 27-day-old female Sprague-Dawley rats were administered daily subcutaneous injections of dehydroepiandrosterone (DHEA, 5 mg/100 g BW) to induce the formation of ovarian follicular cysts. Groups of rats were killed on days 0, 10,15,20,25, and 30. Ovaries from each group of rats were processed for light and electron microscopy and for follicular or cystic fluid hormone analysis. Normal antral follicle fluid, PMSG-treated preovulatory follicular fluid, and cystic fluids were analyzed for progesterone (PI, estrone (El), estradiol (E2), testosterone (TI, A4-androstenedione (A4-A), 5a-dihydrotestosterone (DHT), luteinizing hormone (LH), follicle stimulating hormone (FSH), and prolactin (PRL).
In Situ Localization of Apoptosis in the Rat Ovary during Follicular Atresia1
Biology of Reproduction, 1994
Apoptosis is a type of physiologic cell death that occurs in many tissues and may be regulated by peptide growth factors. Recent studies indicate that apoptosis occurs in the ovary during follicular atresia in several animal species, including the rat, pig, chicken, baboon, and rabbit. The purpose of this study was to demonstrate, through in situ identification of apoptotic cells in intact ovarian sections, the sites in which apoptosis occurs in the rat ovary in different functional states. We evaluated the presence of apoptosis in three models: immature rats, eCG-treated rats and adult cycling rats. Paraffin ovarian sections were pretreated with proteinase K and then end-labeled with biotinylated deoxyuridine triphosphate (dUTP) by incubation with the enzyme terminal deoxynucleotidyl transferase (TDT). They were then stained through use of avidin-conjugated peroxidase with 3,3'-diaminobenzidine as the substrate. Healthy antral and preantral follicles had no staining. The nuclei of granulosa cells of preantral and antral atretic follicles were positively stained in all the animal groups. Scattered theca cells were also stained. Stromal cells were consistently negative. Positive controls were sections pretreated with DNase I; these displayed intense staining of all nuclei. Negative controls, in which either terminal TDT or its biotinylated substrate was omitted, were appropriately negative. This study represents a systematic analysis of apoptosis in the rat ovary at different functional stages and supports the hypothesis that apoptosis is involved in the process of follicular atresia.
Biotechnology & Biotechnological Equipment
Follicular atresia is a process commonly encountered at ovarian level that limits the number of ovulations and, respectively, the reproductive potential of a female. Ovarian cells’ death is essential for maintaining homeostasis of this organ and is based on an apoptotic mechanism that ensures selection of the dominant follicle and the disappearance of follicles in excess. The present study evaluates the incidence of morphological changes specific for this process in the prepubescent mouse ovary by applying optical microscopy techniques. Microscopic analysis was performed on sections of ovarian tissue from mice females’ line NMRI aged 14-17 days. The results show, at this age, significant morphological changes at cellular level, specific for apoptotic process, as condensation and fragmentation of the genetic material, vacuolization of cell cytoplasm, destabilization of cell adhesion junctions and appearance of wide intercellular spaces, invasion of created spaces with infiltrated leu...
Cyclic changes of the ovarian surface epithelium in the rat
Reproduction, 2005
The ovarian surface epithelium (OSE) plays pivotal roles during ovulation and postovulatory wound repair. In this paper we describe the proliferative activity of the OSE through the estrous cycle in adult cycling rats, by immunohistochemical detection of DNA-incorporated bromodeoxyuridine (BrdU). Immunohistochemical detection of estrogen receptor a (ERa) and progesterone receptor was also performed. The cycle of the OSE consists of a proliferative phase (that lasts for two consecutive estrous cycles) and a quiescent phase of variable duration. Cyclic changes in the OSE were related to the underlying ovarian structure. OSE areas covering growing follicles entered into the proliferative phase during the transition from proestrus to estrus, with the appearance of fast-growing class 1 follicles, destined to ovulate at the end of the current estrous cycle. A labeling index (after pulse-labeling BrdU treatment) of about 7% was maintained throughout the estrous cycle in parallel to follicle growth. Cumulative BrdU-labeling (after daily BrdU treatment) indicated that about 1/3 of the total OSE cell proliferation was related to follicle growth. Following ovulation, OSE cells covering newly-formed corpora lutea showed a labeling index of about 50% that decreased through metestrus and diestrus (about 13% and 3%, respectively), returning to basal levels by proestrus. Cumulative BrdU-labeling indicated that about 2/3 of the total proliferative activity was related to ovulation repair/luteinization. The remaining OSE covering ovarian stroma or structurally regressing corpora lutea of previous cycles showed negligible BrdU labeling. The equivalent proliferative activity found in the OSE covering newly-formed corpora lutea in indomethacin-treated rats lacking rupture of the OSE at the apex, demonstrated that ovulation-triggered proliferation was not dependent on the loss of integrity of the OSE at the ovulation site. OSE cells expressed ERa throughout the cycle, but no differential expression was found between proliferating and quiescent OSE areas. On the contrary, OSE cells did not express PR at any time of the cycle. These data indicate the existence of a cycle of the OSE, related to the cyclic changes in the underlying ovarian structure and strongly suggest that the proliferative activity of the OSE is regulated by local microenvironmental rather than by systemic factors. Reproduction (2005) 129 311-321 q 2005 Society for Reproduction and Fertility
Granulosa Cell Apoptosis in the Ovarian Follicle—A Changing View
Frontiers in Endocrinology, 2018
Recent studies challenge the previous view that apoptosis within the granulosa cells of the maturing ovarian follicle is a reflection of aging and consequently a marker for poor quality of the contained oocyte. On the contrary, apoptosis within the granulosa cells is an integral part of normal development and has limited predictive capability regarding oocyte quality or the ensuing pregnancy rate in in vitro fertilization programs. This review article covers our revised understanding of the process of apoptosis within the ovarian follicle, its three phenotypes, the major signaling pathways underlying apoptosis as well as the associated mitochondrial pathways.
Microscopy and Microanalysis, 2014
Organophosphate pesticides (OPs) like malathion interfere with normal ovarian function resulting in an increased incidence of atresia and granulosa cell apoptosis that plays a consequential role in the loss of ovarian follicles or follicular atresia. The aim of present study was to assess malathion-induced (100 nM) reproductive stress, ultrastructural damage and changes in apoptosis frequency in ovarian granulosa cells of antral follicles. Transmission electron microscopy (TEM) was employed for ultrastructural characterization, oxidative stress was evaluated using thiobarbituric acid reactive substances (TBARS) assay to measure lipid peroxidation, and apoptosis was quantified via flow cytometry. By TEM, apoptosis was identified by the presence of an indented nuclear membrane with blebbing, pyknotic crescent-shaped fragmented nuclei, increased vacuolization, degenerating mitochondria, and lipid droplets. The results indicate a significant increase in malondialdehyde (MDA) level (nmol...
Different cell death types determination in juvenile mice ovarian follicles
2018
Follicular atresia is a phenomenon that leads to evacuation of the ovary from the oocytes and the occurrence of menopause. The contribution of various types of cell death in atresia at different follicular developmental stages requires extensive investigation. In this study, we evaluated 3 types of programmed cell death (PCD), apoptosis, autophagy, and necrosis, in juvenile mouse ovary when we can observe all follicular stages as well as atresia. Ovaries from juvenile mice on the 21st post-natal (PN) day were prepared histologically for terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) to evaluate apoptosis and immunohistochemistry for beclin-1 to evaluate the autophagy marker. Necrotic cell death was also assessed by penetration of propidium iodide (PI). The count and percentage of the labeled follicles at different stages in the ovaries were evaluated and compared using the Kruskal-Wallis and Mann-Whitney tests. We detected TUNEL-positive granulosa cells in pre-...