Composition and morphology of the follicular basal lamina during atresia of bovine antral follicles.
Reproduction
; 123(1): 97-106, 2002 Jan.
Article
em En
| MEDLINE
| ID: mdl-11869191
ABSTRACT
The fate of the follicular basal lamina during atresia was investigated using bovine follicles, in which different follicle phenotypes have been observed. These phenotypes include healthy follicles with rounded basal granulosa cells with an aligned basal lamina or follicles with columnar basal granulosa cells with a basal lamina of many loops (loopy), and atretic follicles in which either the antral granulosa cells (antral atresia) or the basal cells (basal atresia) die first. Loopy lamina and basal atresia occur only in small antral follicles < 5 mm in diameter. Follicles were collected from cattle of unknown reproductive history and processed for immunohistochemistry and electron microscopy, and from animals in which follicle growth had been monitored by daily measurements of follicle diameter by ultrasonography. Electron microscopic observations of dominant follicles during the growth phase, plateau and regression showed that the basal lamina was still visible and intact upon atresia. These follicles had a conventional aligned basal lamina, which they retained, except for some degree of folding, as they progressed into antral atresia. In small follicles (2-5 mm in diameter), the basal cell shape (rounded or columnar) and appearance of the basal lamina (aligned or of many loops) did not appear to be related to the type of atresia. On atresia the follicular basal laminae retained immunoreactive laminin alpha1 and beta2, type IV collagen alpha1 and nidogen. Laminin alpha2, which may come from the theca, was present in the follicular basal lamina of only 22% of healthy follicles, but was expressed very commonly in 71% of the atretic follicles. Laminin alpha2 expression was found in both phenotypes of healthy follicles, antral and basal atretic follicles, and follicles with aligned or loopy basal laminae. It is concluded that the basal lamina is not degraded upon atresia, but does undergo a variety of other changes.
Buscar no Google
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Bovinos
/
Atresia Folicular
/
Folículo Ovariano
Limite:
Animals
Idioma:
En
Revista:
Reproduction
Assunto da revista:
MEDICINA REPRODUTIVA
Ano de publicação:
2002
Tipo de documento:
Article
País de afiliação:
Austrália