A stereological study of medium antral follicles during the bovine estrous cycle

• Type: Article in International Scientific Journal
• Date: 2003

Authors

calado, am (Author) Other; rocha, e (Author) ICBAS; colaco, a (Author) Other; sousa, m (Author) ICBAS

Journal

Title: TISSUE & CELL

Vol. 35

Pages: 313-323

ISSN: 0040-8166

Publisher: CHURCHILL LIVINGSTONE

Indexing

ISI Web of Knowledge - 6 Citations

Scopus - 7 Citations

Scientific classification

FOS: Medical and Health sciences > Basic medicine

Other information

Authenticus ID: P-000-F3Q

DOI: 10.1016/s0040-8166(03)00053-3

Abstract (EN): Stereological methods were applied to bovine cumulus-oocyte complexes (COCs) in order to characterize them quantitatively during the estrous cycle. COCs from medium (4-8 mm) antral follicles with a compact and complete cumulus mass, and with an uniform or a non-visible ooplasm were aspirated from ovaries of Holstein-Friesian cows, fixed in glutaraldehyde, randomly embedded in glycol-methacrylate, and sectioned at 20 mum. The unbiased nucleator principle was used for estimating the mean volumes of complexes, oocytes, cumulus cells, and nuclei of oocytes and cumulus cells. The thickness of the zona pellucida and the relative numerical percentages of the several morphological types (C1-C3) of cumulus cells were also evaluated. The optical disector procedure was used for cumulus cell sampling. Quantitative data show that COCs appear heterogeneous for all studied parameters. From metestrus to proestrus the volumes of COCs and oocytes remained constant, the volumes of oocytes and oocyte nuclei were correlated, the thickness of the outer zona pellucida decreased, and the relative numerical frequency of follicular type C3 cells increased. Results suggest that COCs from distinct estrus stages are structurally different, with type C3 follicular cells gradually differentiating from cell types C1 and C2.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 11