Injection of steroid-free bovine follicular fluid (bFF; 2 \m=x\5 ml s.c. 12h apart) into anoestrous ewes lowered plasma FSH concentrations by 70% and after 24 h had significantly (P < 0\m=.\01)reduced the number of non-atretic follicles (\m=ge\1 mm diam.) without influencing the total number of follicles (\m=ge\1 mm diam.) compared to untreated controls. Hourly injections of FSH (10 \g=m\gi.v. ...

BACKGROUND Lysophosphatidic acid (LPA) regulates reproductive processes in the cow. Ovarian granulosa cells play a pivotal role in follicle growth and development. Nevertheless, the role of LPA in the local regulation of granulosa cell function in different follicle categories in the bovine ovary has not been investigated. METHODS Ovarian follicles were divided into healthy, transitional and ...

The distribution of healthy and atretic follicles on the ovarian surface of improved Valachian ewes 17, 24, and 32 days postpartum is reported in this study. The number of healthy follicles was higher on day 24 postpartum and their mean diameter tended to increase to day 32 (P < 0.05) with the greatest diameter of 5 mm. 78-81% of atretic follicles ≥3 mm in diameter was observed where apoptosis ...

Follicular growth over 2 mm in diameter is mainly regulated by gonadotrophins (FSH and LH). However, it is possible that between-follicle interactions may be involved in ensuring ovulation of a specific number of follicles. The present study tested specific hypotheses regarding: (1) a stimulatory role of atretic follicles on differentiation of follicles of the next wave; (2) a stimulatory role ...

BACKGROUND A standard histomorphometric approach has been used for nearly 40 years that identifies atretic (e.g., dying) follicles by counting the number of pyknotic granulosa cells (GC) in the largest follicle cross-section. This method holds that if one pyknotic granulosa nucleus is seen in the largest cross section of a primary follicle, or three pyknotic cells are found in a larger follicle...

BACKGROUND Bovine follicular development is regulated by numerous molecular mechanisms and biological pathways. In this study, we tried to identify differentially expressed genes between largest (F1) and second-largest follicles (F2), and classify them by global gene expression profiling using a combination of microarray and quantitative real-time PCR (QPCR) analysis. The follicular status of F...

A simple and clear means to identify the physiological status of follicles is essential for study of follicular biology. In the present study, we verified a novel classification procedure based on analysis of the follicular population and glucose concentration in follicular fluid (FF) as an alternative method to classify bovine follicles. Paired ovaries were collected from heifers, and the numb...

Follicular atresia has been examined previously by various biochemical and histological methods. The aim of this study was to compare, for the first time, detection of granulosa cell apoptosis by biochemical DNA analysis and microscopic examination of fresh granulosa cell morphology with the established method of detecting atresia by histology in equine follicles. DNA extracted from granulosa c...

This study aimed to investigate the time course of disappearance of the mRNAs of the various subunits of inhibin in follicles which become atretic. An animal model was used in which atresia of preovulatory follicles could be studied in a chronological order. Injection of gonadotrophin-releasing hormone (GnRH) antagonist (20 microg) at the morning of pro-oestrus (P) blocked ovulation and the 10-...

Bovine antral follicles ranging between 2 and 20 mm in diameter were dissected free of stromal tissue and classified under a stereomicroscope using criteria similar to those of Moor et al. (1978). For light-microscopic evaluation of the macroscopic classification, 191 follicles were fixed in Bouin's fluid, embedded in paraffin, sectioned through the cumulus and oocyte and stained with haematoxy...