Multiparametric study of atresia in ewe antral follicles: Histology, flow cytometry, internucleosomal DNA fragmentation, and lysosomal enzyme activities in granulosa cells and follicular fluid

Citation
Am. Rosales-torres et al., Multiparametric study of atresia in ewe antral follicles: Histology, flow cytometry, internucleosomal DNA fragmentation, and lysosomal enzyme activities in granulosa cells and follicular fluid, MOL REPROD, 55(3), 2000, pp. 270-281
Citations number
71
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Cell & Developmental Biology
Journal title
MOLECULAR REPRODUCTION AND DEVELOPMENT
ISSN journal
1040-452X → ACNP
Volume
55
Issue
3
Year of publication
2000
Pages
270 - 281
Database
ISI
SICI code
1040-452X(200003)55:3<270:MSOAIE>2.0.ZU;2-N
Abstract
The differential quantitative participation of apoptosis and necrosis in ew e antral follicles of two different sizes, separated in four stages of atre sia using macroscopic, histologic, and esteroid quantification methods was assessed. Annexin V binding and propidium iodide (PI) uptake was used to de tect healthy five cells (Annexin V negative/PI negative), early apoptotic c ells (Annexin V+/PI-), and necrotic or late apoptotic cells (PI+). Addition ally we used internucleosomal DNA fragmentation as a quantitative estimate of apoptosis. Presence and distribution of lysosomal enzymes in follicular fluid and granulosa cells was used as a measure of necrotic cell death. DNA flow citometry and gel electrophoresis were positively correlated with the progression of atresia, small atretic follicles tend to have higher percen tages of internucleosomal cleaved DNA than follicles >6 mm. Annexin/PI bind ing also indicates that apoptosis and necrosis increase with atresia progre ssion, generally apoptosis outweighs necrosis in small follicles. Acid phos phatase and glucosaminidase in follicular fluid of 3-6 mm follicles showed no significant modifications between healthy and initially atretic follicle s, and only a small, but significant increase in activity in advancedly atr etic follicles. On the contrary, lysosomal enzyme activity in follicles >6 mm showed positive correlation between atresia stages and the activities of acid phosphatase and glucosaminidase in follicular fluid. A similar size d ifferential behavior was found in free or membrane bound lysosomal enzyme a ctivity of granulosa cells. Necrosis, but principally apoptosis, were prese nt during all stages of follicular maturation indicating that growth and ma turation of ovarian follicles involves a continuous renewal of granulosa ce lls, regulated by apoptosis. Mechanisms regulating this equilibrium may par ticipate in the final destiny, whether ovulation or atresia of ovarian foll icles. Mel. Reprod. Dev. 55:270-281, 2000. (C) 2000 Wiley-Liss, Inc.