Steroidogenic acute regulatory protein in ovarian follicles of gonadotropin-stimulated rats is regulated by a gonadotropin-releasing hormone agonist
The aim of the present study was to examine the acute and chronic effects of the gonadotropin-releasing hormone agonist (GnRH-a) leuprolide acetate (LA) on the expression of the steroidogenic acute regulatory protein (StAR), the cytochrome P450 side-chain cleavage enzyme (P450scc), and steroid produ...
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2003
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00063363_v68_n5_p1577_Irusta http://hdl.handle.net/20.500.12110/paper_00063363_v68_n5_p1577_Irusta |
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paper:paper_00063363_v68_n5_p1577_Irusta2023-06-08T14:31:04Z Steroidogenic acute regulatory protein in ovarian follicles of gonadotropin-stimulated rats is regulated by a gonadotropin-releasing hormone agonist Follicle Follicular development Gonadotropin-releasing hormone Ovary Steroid hormones androgen androsterone cholesterol monooxygenase (side chain cleaving) chorionic gonadotropin gonadotropin growth hormone releasing factor agonist leuprorelin messenger RNA progesterone steroidogenic acute regulatory protein testosterone unclassified drug animal cell animal experiment animal tissue article controlled study dose response female hormonal therapy nonhuman ovary follicle prepuberty priority journal protein expression rat regulatory mechanism reverse transcription polymerase chain reaction steroidogenesis Androgens Animals Blotting, Western Cholesterol Side-Chain Cleavage Enzyme Estradiol Female Gonadotropin-Releasing Hormone Gonadotropins Gonadotropins, Equine Leuprolide Ovarian Follicle Ovary Phosphoproteins Progesterone Radioimmunoassay Rats Rats, Sprague-Dawley Reverse Transcriptase Polymerase Chain Reaction Steroids Stimulation, Chemical Animalia Equidae Eukaryota The aim of the present study was to examine the acute and chronic effects of the gonadotropin-releasing hormone agonist (GnRH-a) leuprolide acetate (LA) on the expression of the steroidogenic acute regulatory protein (StAR), the cytochrome P450 side-chain cleavage enzyme (P450scc), and steroid production in antral ovarian follicles obtained from prepubertal equine choriogonadotropin (eCG)-treated rats. Follicular contents of StAR and P450scc proteins were measured by Western blotting following in vivo injection of eCG (control) and eCG+LA (LA) to prepubertal rats. Treatment with eCG for 2 h resulted in no change in StAR protein content, but it was markedly increased at 4 and 8 h after hormone treatment. However, coadministration of eCG+LA produced a significant increase (P < 0.05) in StAR protein levels at 2, 4, and 8 h when compared with eCG treatment. Acute and chronic treatment with either eCG or eCG+LA did not alter the P450scc protein levels in freshly isolated follicles. The increase in StAR protein expression following LA treatment was qualitatively similar to StAR mRNA expression, as determined by quantitative reverse transcription-polymerase chain reaction (RT-PCR) analysis. Furthermore, administration of eCG demonstrated a time-dependent increase (2-8 h) in the levels of StAR mRNA, and these levels were markedly increased by eCG+LA. However, the temporal response pattern of StAR mRNA was much greater at 2 h following LA administration when compared with controls. In addition, 48 h of LA treatment in eCG-treated rats resulted in a significant increase (P < 0.05) in follicular progesterone levels, whereas significant decreases in androgen (testosterone and androsterone) and estradiol levels were observed. Similar results were obtained when serum androgens and estradiol were measured, but serum progesterone levels were unchanged. Collectively, these findings demonstrate that the inhibitory effect of LA on ovarian androgen and estradiol levels is related to changes in the follicular levels of StAR protein and steroid production. 2003 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00063363_v68_n5_p1577_Irusta http://hdl.handle.net/20.500.12110/paper_00063363_v68_n5_p1577_Irusta |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
Follicle Follicular development Gonadotropin-releasing hormone Ovary Steroid hormones androgen androsterone cholesterol monooxygenase (side chain cleaving) chorionic gonadotropin gonadotropin growth hormone releasing factor agonist leuprorelin messenger RNA progesterone steroidogenic acute regulatory protein testosterone unclassified drug animal cell animal experiment animal tissue article controlled study dose response female hormonal therapy nonhuman ovary follicle prepuberty priority journal protein expression rat regulatory mechanism reverse transcription polymerase chain reaction steroidogenesis Androgens Animals Blotting, Western Cholesterol Side-Chain Cleavage Enzyme Estradiol Female Gonadotropin-Releasing Hormone Gonadotropins Gonadotropins, Equine Leuprolide Ovarian Follicle Ovary Phosphoproteins Progesterone Radioimmunoassay Rats Rats, Sprague-Dawley Reverse Transcriptase Polymerase Chain Reaction Steroids Stimulation, Chemical Animalia Equidae Eukaryota |
| spellingShingle |
Follicle Follicular development Gonadotropin-releasing hormone Ovary Steroid hormones androgen androsterone cholesterol monooxygenase (side chain cleaving) chorionic gonadotropin gonadotropin growth hormone releasing factor agonist leuprorelin messenger RNA progesterone steroidogenic acute regulatory protein testosterone unclassified drug animal cell animal experiment animal tissue article controlled study dose response female hormonal therapy nonhuman ovary follicle prepuberty priority journal protein expression rat regulatory mechanism reverse transcription polymerase chain reaction steroidogenesis Androgens Animals Blotting, Western Cholesterol Side-Chain Cleavage Enzyme Estradiol Female Gonadotropin-Releasing Hormone Gonadotropins Gonadotropins, Equine Leuprolide Ovarian Follicle Ovary Phosphoproteins Progesterone Radioimmunoassay Rats Rats, Sprague-Dawley Reverse Transcriptase Polymerase Chain Reaction Steroids Stimulation, Chemical Animalia Equidae Eukaryota Steroidogenic acute regulatory protein in ovarian follicles of gonadotropin-stimulated rats is regulated by a gonadotropin-releasing hormone agonist |
| topic_facet |
Follicle Follicular development Gonadotropin-releasing hormone Ovary Steroid hormones androgen androsterone cholesterol monooxygenase (side chain cleaving) chorionic gonadotropin gonadotropin growth hormone releasing factor agonist leuprorelin messenger RNA progesterone steroidogenic acute regulatory protein testosterone unclassified drug animal cell animal experiment animal tissue article controlled study dose response female hormonal therapy nonhuman ovary follicle prepuberty priority journal protein expression rat regulatory mechanism reverse transcription polymerase chain reaction steroidogenesis Androgens Animals Blotting, Western Cholesterol Side-Chain Cleavage Enzyme Estradiol Female Gonadotropin-Releasing Hormone Gonadotropins Gonadotropins, Equine Leuprolide Ovarian Follicle Ovary Phosphoproteins Progesterone Radioimmunoassay Rats Rats, Sprague-Dawley Reverse Transcriptase Polymerase Chain Reaction Steroids Stimulation, Chemical Animalia Equidae Eukaryota |
| description |
The aim of the present study was to examine the acute and chronic effects of the gonadotropin-releasing hormone agonist (GnRH-a) leuprolide acetate (LA) on the expression of the steroidogenic acute regulatory protein (StAR), the cytochrome P450 side-chain cleavage enzyme (P450scc), and steroid production in antral ovarian follicles obtained from prepubertal equine choriogonadotropin (eCG)-treated rats. Follicular contents of StAR and P450scc proteins were measured by Western blotting following in vivo injection of eCG (control) and eCG+LA (LA) to prepubertal rats. Treatment with eCG for 2 h resulted in no change in StAR protein content, but it was markedly increased at 4 and 8 h after hormone treatment. However, coadministration of eCG+LA produced a significant increase (P < 0.05) in StAR protein levels at 2, 4, and 8 h when compared with eCG treatment. Acute and chronic treatment with either eCG or eCG+LA did not alter the P450scc protein levels in freshly isolated follicles. The increase in StAR protein expression following LA treatment was qualitatively similar to StAR mRNA expression, as determined by quantitative reverse transcription-polymerase chain reaction (RT-PCR) analysis. Furthermore, administration of eCG demonstrated a time-dependent increase (2-8 h) in the levels of StAR mRNA, and these levels were markedly increased by eCG+LA. However, the temporal response pattern of StAR mRNA was much greater at 2 h following LA administration when compared with controls. In addition, 48 h of LA treatment in eCG-treated rats resulted in a significant increase (P < 0.05) in follicular progesterone levels, whereas significant decreases in androgen (testosterone and androsterone) and estradiol levels were observed. Similar results were obtained when serum androgens and estradiol were measured, but serum progesterone levels were unchanged. Collectively, these findings demonstrate that the inhibitory effect of LA on ovarian androgen and estradiol levels is related to changes in the follicular levels of StAR protein and steroid production. |
| title |
Steroidogenic acute regulatory protein in ovarian follicles of gonadotropin-stimulated rats is regulated by a gonadotropin-releasing hormone agonist |
| title_short |
Steroidogenic acute regulatory protein in ovarian follicles of gonadotropin-stimulated rats is regulated by a gonadotropin-releasing hormone agonist |
| title_full |
Steroidogenic acute regulatory protein in ovarian follicles of gonadotropin-stimulated rats is regulated by a gonadotropin-releasing hormone agonist |
| title_fullStr |
Steroidogenic acute regulatory protein in ovarian follicles of gonadotropin-stimulated rats is regulated by a gonadotropin-releasing hormone agonist |
| title_full_unstemmed |
Steroidogenic acute regulatory protein in ovarian follicles of gonadotropin-stimulated rats is regulated by a gonadotropin-releasing hormone agonist |
| title_sort |
steroidogenic acute regulatory protein in ovarian follicles of gonadotropin-stimulated rats is regulated by a gonadotropin-releasing hormone agonist |
| publishDate |
2003 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00063363_v68_n5_p1577_Irusta http://hdl.handle.net/20.500.12110/paper_00063363_v68_n5_p1577_Irusta |
| _version_ |
1768542248601911296 |