Effects of a gonadotropin-releasing hormone agonist on rat ovarian follicle apoptosis: Regulation by epidermal growth factor and the expression of Bcl-2-related genes

The purpose of the present study was to evaluate the in vivo effect of the GnRH analogue leuprolide acetate (LA) on follicular development and apoptosis-related mechanisms in preovulatory ovarian follicles (POF) obtained from prepubertal eCG-treated rats. Serum progesterone and estradiol levels were...

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Publicado: 2002
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rat
Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00063363_v67_n2_p481_Parborell
http://hdl.handle.net/20.500.12110/paper_00063363_v67_n2_p481_Parborell
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spelling paper:paper_00063363_v67_n2_p481_Parborell2023-06-08T14:31:03Z Effects of a gonadotropin-releasing hormone agonist on rat ovarian follicle apoptosis: Regulation by epidermal growth factor and the expression of Bcl-2-related genes Apoptosis Follicle Gonadotropin-releasing hormone Growth factors Ovary DNA fragment epidermal growth factor estradiol gonadorelin agonist leuprorelin progesterone protein Bax protein bcl 2 protein bcl xl chorionic gonadotropin DNA DNA fragment epidermal growth factor gonadorelin leuprorelin progesterone animal cell apoptosis article controlled study DNA degradation estradiol blood level female gene expression regulation nonhuman ovary follicle ovary follicle atresia ovary follicle development priority journal progesterone blood level protein stability rat animal biosynthesis blood drug effect drug potentiation gene expression regulation genetics histology immunohistochemistry nick end labeling physiology polyacrylamide gel electrophoresis proto oncogene Sprague Dawley rat Western blotting Animalia Eukaryota Fallopia Animals Apoptosis Blotting, Western Chorionic Gonadotropin DNA DNA Fragmentation Electrophoresis, Polyacrylamide Gel Epidermal Growth Factor Female Gene Expression Regulation Genes, bcl-2 Gonadotropin-Releasing Hormone Immunohistochemistry In Situ Nick-End Labeling Leuprolide Ovarian Follicle Progesterone Rats Rats, Sprague-Dawley The purpose of the present study was to evaluate the in vivo effect of the GnRH analogue leuprolide acetate (LA) on follicular development and apoptosis-related mechanisms in preovulatory ovarian follicles (POF) obtained from prepubertal eCG-treated rats. Serum progesterone and estradiol levels were measured, and a significant decrease in circulating estradiol levels was observed in the LA group, whereas serum progesterone levels remained unchanged. Ovarian histology revealed an inhibitory effect of LA treatment on the follicular development induced by eCG. After 48 h of LA treatment, the numbers of atretic and preantral follicles were increased as compared with controls, whereas the number of antral follicles had decreased. Cells undergoing DNA fragmentation were quantified by performing in situ 3′ end labeling of DNA with digoxygenin-dUTP on ovarian sections. LA treatment caused an increase in the percentage of apoptotic cells in preantral and antral follicles. DNA isolated from these POF incubated 24 h in serum-free medium exhibited the typical apoptotic DNA degradation pattern. Treatment of follicles with epidermal growth factor (EGF) suppressed the spontaneous onset of DNA fragmentation, and a similar effect was observed in LA follicles. POF obtained from LA-treated rats showed no changes in Bcl-2 or Bax protein levels. However, a reduction in the Bcl-xL:Bcl-xS ratio was observed, with a greater decrease in Bcl-xL compared with Bcl-xS during the incubation, suggesting a lower stability of the Bcl-xL isoform in the LA group. These results indicate that in vivo GnRH agonist treatment produces an increase in the apoptosis process in POF from eCG-treated rats, and this effect is reversed in vitro by EGF. This GnRH analogue also reduced the stability of the Bcl-xL protein, thus interfering with follicular development by an as yet unknown mechanism. 2002 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00063363_v67_n2_p481_Parborell http://hdl.handle.net/20.500.12110/paper_00063363_v67_n2_p481_Parborell
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Apoptosis
Follicle
Gonadotropin-releasing hormone
Growth factors
Ovary
DNA fragment
epidermal growth factor
estradiol
gonadorelin agonist
leuprorelin
progesterone
protein Bax
protein bcl 2
protein bcl xl
chorionic gonadotropin
DNA
DNA fragment
epidermal growth factor
gonadorelin
leuprorelin
progesterone
animal cell
apoptosis
article
controlled study
DNA degradation
estradiol blood level
female
gene expression regulation
nonhuman
ovary follicle
ovary follicle atresia
ovary follicle development
priority journal
progesterone blood level
protein stability
rat
animal
biosynthesis
blood
drug effect
drug potentiation
gene expression regulation
genetics
histology
immunohistochemistry
nick end labeling
physiology
polyacrylamide gel electrophoresis
proto oncogene
Sprague Dawley rat
Western blotting
Animalia
Eukaryota
Fallopia
Animals
Apoptosis
Blotting, Western
Chorionic Gonadotropin
DNA
DNA Fragmentation
Electrophoresis, Polyacrylamide Gel
Epidermal Growth Factor
Female
Gene Expression Regulation
Genes, bcl-2
Gonadotropin-Releasing Hormone
Immunohistochemistry
In Situ Nick-End Labeling
Leuprolide
Ovarian Follicle
Progesterone
Rats
Rats, Sprague-Dawley
spellingShingle Apoptosis
Follicle
Gonadotropin-releasing hormone
Growth factors
Ovary
DNA fragment
epidermal growth factor
estradiol
gonadorelin agonist
leuprorelin
progesterone
protein Bax
protein bcl 2
protein bcl xl
chorionic gonadotropin
DNA
DNA fragment
epidermal growth factor
gonadorelin
leuprorelin
progesterone
animal cell
apoptosis
article
controlled study
DNA degradation
estradiol blood level
female
gene expression regulation
nonhuman
ovary follicle
ovary follicle atresia
ovary follicle development
priority journal
progesterone blood level
protein stability
rat
animal
biosynthesis
blood
drug effect
drug potentiation
gene expression regulation
genetics
histology
immunohistochemistry
nick end labeling
physiology
polyacrylamide gel electrophoresis
proto oncogene
Sprague Dawley rat
Western blotting
Animalia
Eukaryota
Fallopia
Animals
Apoptosis
Blotting, Western
Chorionic Gonadotropin
DNA
DNA Fragmentation
Electrophoresis, Polyacrylamide Gel
Epidermal Growth Factor
Female
Gene Expression Regulation
Genes, bcl-2
Gonadotropin-Releasing Hormone
Immunohistochemistry
In Situ Nick-End Labeling
Leuprolide
Ovarian Follicle
Progesterone
Rats
Rats, Sprague-Dawley
Effects of a gonadotropin-releasing hormone agonist on rat ovarian follicle apoptosis: Regulation by epidermal growth factor and the expression of Bcl-2-related genes
topic_facet Apoptosis
Follicle
Gonadotropin-releasing hormone
Growth factors
Ovary
DNA fragment
epidermal growth factor
estradiol
gonadorelin agonist
leuprorelin
progesterone
protein Bax
protein bcl 2
protein bcl xl
chorionic gonadotropin
DNA
DNA fragment
epidermal growth factor
gonadorelin
leuprorelin
progesterone
animal cell
apoptosis
article
controlled study
DNA degradation
estradiol blood level
female
gene expression regulation
nonhuman
ovary follicle
ovary follicle atresia
ovary follicle development
priority journal
progesterone blood level
protein stability
rat
animal
biosynthesis
blood
drug effect
drug potentiation
gene expression regulation
genetics
histology
immunohistochemistry
nick end labeling
physiology
polyacrylamide gel electrophoresis
proto oncogene
Sprague Dawley rat
Western blotting
Animalia
Eukaryota
Fallopia
Animals
Apoptosis
Blotting, Western
Chorionic Gonadotropin
DNA
DNA Fragmentation
Electrophoresis, Polyacrylamide Gel
Epidermal Growth Factor
Female
Gene Expression Regulation
Genes, bcl-2
Gonadotropin-Releasing Hormone
Immunohistochemistry
In Situ Nick-End Labeling
Leuprolide
Ovarian Follicle
Progesterone
Rats
Rats, Sprague-Dawley
description The purpose of the present study was to evaluate the in vivo effect of the GnRH analogue leuprolide acetate (LA) on follicular development and apoptosis-related mechanisms in preovulatory ovarian follicles (POF) obtained from prepubertal eCG-treated rats. Serum progesterone and estradiol levels were measured, and a significant decrease in circulating estradiol levels was observed in the LA group, whereas serum progesterone levels remained unchanged. Ovarian histology revealed an inhibitory effect of LA treatment on the follicular development induced by eCG. After 48 h of LA treatment, the numbers of atretic and preantral follicles were increased as compared with controls, whereas the number of antral follicles had decreased. Cells undergoing DNA fragmentation were quantified by performing in situ 3′ end labeling of DNA with digoxygenin-dUTP on ovarian sections. LA treatment caused an increase in the percentage of apoptotic cells in preantral and antral follicles. DNA isolated from these POF incubated 24 h in serum-free medium exhibited the typical apoptotic DNA degradation pattern. Treatment of follicles with epidermal growth factor (EGF) suppressed the spontaneous onset of DNA fragmentation, and a similar effect was observed in LA follicles. POF obtained from LA-treated rats showed no changes in Bcl-2 or Bax protein levels. However, a reduction in the Bcl-xL:Bcl-xS ratio was observed, with a greater decrease in Bcl-xL compared with Bcl-xS during the incubation, suggesting a lower stability of the Bcl-xL isoform in the LA group. These results indicate that in vivo GnRH agonist treatment produces an increase in the apoptosis process in POF from eCG-treated rats, and this effect is reversed in vitro by EGF. This GnRH analogue also reduced the stability of the Bcl-xL protein, thus interfering with follicular development by an as yet unknown mechanism.
title Effects of a gonadotropin-releasing hormone agonist on rat ovarian follicle apoptosis: Regulation by epidermal growth factor and the expression of Bcl-2-related genes
title_short Effects of a gonadotropin-releasing hormone agonist on rat ovarian follicle apoptosis: Regulation by epidermal growth factor and the expression of Bcl-2-related genes
title_full Effects of a gonadotropin-releasing hormone agonist on rat ovarian follicle apoptosis: Regulation by epidermal growth factor and the expression of Bcl-2-related genes
title_fullStr Effects of a gonadotropin-releasing hormone agonist on rat ovarian follicle apoptosis: Regulation by epidermal growth factor and the expression of Bcl-2-related genes
title_full_unstemmed Effects of a gonadotropin-releasing hormone agonist on rat ovarian follicle apoptosis: Regulation by epidermal growth factor and the expression of Bcl-2-related genes
title_sort effects of a gonadotropin-releasing hormone agonist on rat ovarian follicle apoptosis: regulation by epidermal growth factor and the expression of bcl-2-related genes
publishDate 2002
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00063363_v67_n2_p481_Parborell
http://hdl.handle.net/20.500.12110/paper_00063363_v67_n2_p481_Parborell
_version_ 1768542484984496128