title: Involvement of cell proliferation in the process of follicular atresia in the guinea pig.
abstract: Cell morphology and proliferation was investigated in the atretic follicles during estrous cycles in the guinea pig. Ovarian samples on days 1, 4, 8, 12 and 16 of the estrous cycle in the guinea pig were taken in the morning for histologic staining with hematoxylin and eosin (HE), and immunohistochemical staining of the protein proliferating cell nuclear antigen (PCNA). The results indicated that the granulosa cells degenerated and eliminated first in atretic follicles, while the fibroblast-like cells appeared in the innermost layer of theca interna cells. When the fibroblast-like cells migrated to the antrum, they proliferated and formed a new tissue in peripheral to the zona pellucida of the oocyte. Our results also revealed that the orientation of the theca interna cell arrangement changed twice during the process of atresia, and the loose connective tissue in the antrum was critical for follicular atresia. Therefore, follicular atresia was not a simple process of cell death and elimination, but coexisted with cell proliferation. To our knowledge, we have for the first time confirmed cell proliferation and the presence of new tissue in atretic follicles in guinea pigs.
authors.affiliation: Laboratory of Animal Reproduction, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, PR China. weigrstar@yahoo.com.cn
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.forename: Honglin
authors.initials: H
authors.lastname: Liu
authors.forename: Wei
authors.initials: W
authors.lastname: Ding
authors.forename: Yan
authors.initials: Y
authors.lastname: Gong
authors.forename: Jingwei
authors.initials: J
authors.lastname: Chen
authors.forename: Reinhold J
authors.initials: RJ
authors.lastname: Hutz
authors.forename: Dagan
authors.initials: D
authors.lastname: Mao
authors.forename: Fangxiong
authors.initials: F
authors.lastname: Shi
mesh_terms: D000818:Animals; D049109:Cell Proliferation; D030762:Estrous Cycle / Q000502:physiology; D005260:Female; D005496:Follicular Atresia / Q000502:physiology*; D006168:Guinea Pigs; D007150:Immunohistochemistry; D006080:Ovarian Follicle / Q000166:cytology / Q000378:metabolism; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism; D013799:Theca Cells / Q000166:cytology / Q000378:metabolism
chemical_list: D018809:Proliferating Cell Nuclear Antigen