Atresia of large ovarian follicles of the rat
In the rat, at the beginning of pregnancy a cohort of antral follicles develops until the preovulatory stage. However, these follicles, differentiating in the hyperprolactinemic milieu, produce only small amount of estradiol, do not ovulate and undergo rapid degeneration. They constitute an interest...
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| Format: | Article |
| Language: | English |
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Via Medica
2011-08-01
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| Series: | Folia Histochemica et Cytobiologica |
| Subjects: | |
| Online Access: | http://czasopisma.viamedica.pl/fhc/article/view/4628 |
| _version_ | 1819130708630700032 |
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| author | Maria Słomczyn´ ska Małgorzata Bik Maria Szołtys Zbigniew Tabarowski |
| author_facet | Maria Słomczyn´ ska Małgorzata Bik Maria Szołtys Zbigniew Tabarowski |
| author_sort | Maria Słomczyn´ ska |
| collection | DOAJ |
| description | In the rat, at the beginning of pregnancy a cohort of antral follicles develops until the preovulatory stage. However, these follicles, differentiating in the hyperprolactinemic milieu, produce only small amount of estradiol, do not ovulate and undergo rapid degeneration. They constitute an interesting physiological model of atresia. In the present study, we analysed the development and subsequent degeneration of such follicles. The study was performed on Wistar female rats killed in succession between days 1-9 of pregnancy. Excised ovaries were submitted to a routine histological procedure. Paraffin sections were subjected to hematoxylin and eosin staining or <i>in situ</i> DNA labelling. Histological and TUNEL staining revealed that the investigated group of follicles grew slower than that on the corresponding days of the estrous cycle and reached a preovulatory size and morphological appearance on day 5 of pregnancy. They did not ovulate and between days 6 and 9 of pregnancy an increasing number of apoptotic cells appeared within these follicles. They were localized predominantly in the antral granulosa layer, especially near the cumulus oophorus complex (COC) and in the region linking the COC with the follicular wall. The COC and the theca layer were much less affected. In late stages of atresia, also cumulus cells became apoptotic but degenerating oocytes did not exhibit positive TUNEL staining. Only limited number of the theca cells have undergone apoptosis and generally they were not hypertrophied. Our findings indicate that much smaller than normal amount of intrafollicular estradiol was sufficient to support a normal, according to the morphological criteria, although slower development of antral follicles to the late preovulatory stage. |
| first_indexed | 2024-12-22T09:03:54Z |
| format | Article |
| id | doaj.art-45a4441b960441e7bc5ab93eb68e08c9 |
| institution | Directory Open Access Journal |
| issn | 0239-8508 1897-5631 |
| language | English |
| last_indexed | 2024-12-22T09:03:54Z |
| publishDate | 2011-08-01 |
| publisher | Via Medica |
| record_format | Article |
| series | Folia Histochemica et Cytobiologica |
| spelling | doaj.art-45a4441b960441e7bc5ab93eb68e08c92022-12-21T18:31:38ZengVia MedicaFolia Histochemica et Cytobiologica0239-85081897-56312011-08-01431435010.5603/4628Atresia of large ovarian follicles of the ratMaria Słomczyn´ skaMałgorzata BikMaria SzołtysZbigniew TabarowskiIn the rat, at the beginning of pregnancy a cohort of antral follicles develops until the preovulatory stage. However, these follicles, differentiating in the hyperprolactinemic milieu, produce only small amount of estradiol, do not ovulate and undergo rapid degeneration. They constitute an interesting physiological model of atresia. In the present study, we analysed the development and subsequent degeneration of such follicles. The study was performed on Wistar female rats killed in succession between days 1-9 of pregnancy. Excised ovaries were submitted to a routine histological procedure. Paraffin sections were subjected to hematoxylin and eosin staining or <i>in situ</i> DNA labelling. Histological and TUNEL staining revealed that the investigated group of follicles grew slower than that on the corresponding days of the estrous cycle and reached a preovulatory size and morphological appearance on day 5 of pregnancy. They did not ovulate and between days 6 and 9 of pregnancy an increasing number of apoptotic cells appeared within these follicles. They were localized predominantly in the antral granulosa layer, especially near the cumulus oophorus complex (COC) and in the region linking the COC with the follicular wall. The COC and the theca layer were much less affected. In late stages of atresia, also cumulus cells became apoptotic but degenerating oocytes did not exhibit positive TUNEL staining. Only limited number of the theca cells have undergone apoptosis and generally they were not hypertrophied. Our findings indicate that much smaller than normal amount of intrafollicular estradiol was sufficient to support a normal, according to the morphological criteria, although slower development of antral follicles to the late preovulatory stage.http://czasopisma.viamedica.pl/fhc/article/view/4628ApoptosisPreovulatory folliclesHyperprolactinemiaRat |
| spellingShingle | Maria Słomczyn´ ska Małgorzata Bik Maria Szołtys Zbigniew Tabarowski Atresia of large ovarian follicles of the rat Folia Histochemica et Cytobiologica Apoptosis Preovulatory follicles Hyperprolactinemia Rat |
| title | Atresia of large ovarian follicles of the rat |
| title_full | Atresia of large ovarian follicles of the rat |
| title_fullStr | Atresia of large ovarian follicles of the rat |
| title_full_unstemmed | Atresia of large ovarian follicles of the rat |
| title_short | Atresia of large ovarian follicles of the rat |
| title_sort | atresia of large ovarian follicles of the rat |
| topic | Apoptosis Preovulatory follicles Hyperprolactinemia Rat |
| url | http://czasopisma.viamedica.pl/fhc/article/view/4628 |
| work_keys_str_mv | AT mariasłomczynska atresiaoflargeovarianfolliclesoftherat AT małgorzatabik atresiaoflargeovarianfolliclesoftherat AT mariaszołtys atresiaoflargeovarianfolliclesoftherat AT zbigniewtabarowski atresiaoflargeovarianfolliclesoftherat |