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Sympathetic nerve activity in normal and cystic follicles from isolated bovine ovary: local effect of beta-adrenergic stimulation on steroid secretion.

Paredes AH, Salvetti NR, Diaz AE, Dallard BE, Ortega HH, Lara HE - Reprod. Biol. Endocrinol. (2011)

Bottom Line: Cystic follicles which present an area 600 fold greater compared with preovulatory follicles has only 10 times less concentration of NE as compared with small antral and preovulatory follicles but they had 10 times more NE in follicular fluid, suggesting a high efflux of neurotransmitter from the cyst wall.This suggestion was reinforced by the high basal release of recently taken-up 3H-NE found in cystic follicles.While lower levels of beta-adrenergic receptor were found in cystic follicles, there was a heightened response to the beta-adrenergic agonist isoproterenol and to hCG, as measured by testosterone secretion.

View Article: PubMed Central - HTML - PubMed

Affiliation: Laboratory of Neurobiochemistry, Department of Biochemistry and Molecular Biology, Faculty of Chemistry and Pharmaceutical Sciences, Universidad de Chile, Santiago, Chile. aparedes@ciq.uchile.cl

ABSTRACT
Cystic ovarian disease (COD) is an important cause of abnormal estrous behavior and infertility in dairy cows. COD is mainly observed in high-yielding dairy cows during the first months post-partum, a period of high stress. We have previously reported that, in lower mammals, stress induces a cystic condition similar to the polycystic ovary syndrome in humans and that stress is a definitive component in the human pathology. To know if COD in cows is also associated with high sympathetic activity, we studied isolated small antral (5 mm), preovulatory (10 mm) and cystic follicles (25 mm). Cystic follicles which present an area 600 fold greater compared with preovulatory follicles has only 10 times less concentration of NE as compared with small antral and preovulatory follicles but they had 10 times more NE in follicular fluid, suggesting a high efflux of neurotransmitter from the cyst wall. This suggestion was reinforced by the high basal release of recently taken-up 3H-NE found in cystic follicles. While lower levels of beta-adrenergic receptor were found in cystic follicles, there was a heightened response to the beta-adrenergic agonist isoproterenol and to hCG, as measured by testosterone secretion. There was however an unexpected capacity of the ovary in vitro to produce cortisol and to secrete it in response to hCG but not to isoproterenol. These data suggest that, during COD, the bovine ovary is under high sympathetic nerve activity that in addition to an increased response to hCG in cortisol secretion could participate in COD development.

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Concentration of β-adrenergic receptor from small antral (SA), preovulatory (PO) and cystic follicular wall. The β-receptor concentration is expressed as fmol of dihydroalprenolol bound/mg of membrane protein. Each bar represents the mean ± SEM of 4 experiments, for each group. * = p < 0.01 vs. preovulatory follicular wall.
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Figure 4: Concentration of β-adrenergic receptor from small antral (SA), preovulatory (PO) and cystic follicular wall. The β-receptor concentration is expressed as fmol of dihydroalprenolol bound/mg of membrane protein. Each bar represents the mean ± SEM of 4 experiments, for each group. * = p < 0.01 vs. preovulatory follicular wall.

Mentions: We determined the total amount of binding sites by incubating tissue with a 20 nM saturating concentration of 3H-dihydroalprenolol (Figure 4). The highest number of binding sites (expressed per mg of protein) was found in PO follicles; cystic follicles presented the lowest number.


Sympathetic nerve activity in normal and cystic follicles from isolated bovine ovary: local effect of beta-adrenergic stimulation on steroid secretion.

Paredes AH, Salvetti NR, Diaz AE, Dallard BE, Ortega HH, Lara HE - Reprod. Biol. Endocrinol. (2011)

Concentration of β-adrenergic receptor from small antral (SA), preovulatory (PO) and cystic follicular wall. The β-receptor concentration is expressed as fmol of dihydroalprenolol bound/mg of membrane protein. Each bar represents the mean ± SEM of 4 experiments, for each group. * = p < 0.01 vs. preovulatory follicular wall.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3117772&req=5

Figure 4: Concentration of β-adrenergic receptor from small antral (SA), preovulatory (PO) and cystic follicular wall. The β-receptor concentration is expressed as fmol of dihydroalprenolol bound/mg of membrane protein. Each bar represents the mean ± SEM of 4 experiments, for each group. * = p < 0.01 vs. preovulatory follicular wall.
Mentions: We determined the total amount of binding sites by incubating tissue with a 20 nM saturating concentration of 3H-dihydroalprenolol (Figure 4). The highest number of binding sites (expressed per mg of protein) was found in PO follicles; cystic follicles presented the lowest number.

Bottom Line: Cystic follicles which present an area 600 fold greater compared with preovulatory follicles has only 10 times less concentration of NE as compared with small antral and preovulatory follicles but they had 10 times more NE in follicular fluid, suggesting a high efflux of neurotransmitter from the cyst wall.This suggestion was reinforced by the high basal release of recently taken-up 3H-NE found in cystic follicles.While lower levels of beta-adrenergic receptor were found in cystic follicles, there was a heightened response to the beta-adrenergic agonist isoproterenol and to hCG, as measured by testosterone secretion.

View Article: PubMed Central - HTML - PubMed

Affiliation: Laboratory of Neurobiochemistry, Department of Biochemistry and Molecular Biology, Faculty of Chemistry and Pharmaceutical Sciences, Universidad de Chile, Santiago, Chile. aparedes@ciq.uchile.cl

ABSTRACT
Cystic ovarian disease (COD) is an important cause of abnormal estrous behavior and infertility in dairy cows. COD is mainly observed in high-yielding dairy cows during the first months post-partum, a period of high stress. We have previously reported that, in lower mammals, stress induces a cystic condition similar to the polycystic ovary syndrome in humans and that stress is a definitive component in the human pathology. To know if COD in cows is also associated with high sympathetic activity, we studied isolated small antral (5 mm), preovulatory (10 mm) and cystic follicles (25 mm). Cystic follicles which present an area 600 fold greater compared with preovulatory follicles has only 10 times less concentration of NE as compared with small antral and preovulatory follicles but they had 10 times more NE in follicular fluid, suggesting a high efflux of neurotransmitter from the cyst wall. This suggestion was reinforced by the high basal release of recently taken-up 3H-NE found in cystic follicles. While lower levels of beta-adrenergic receptor were found in cystic follicles, there was a heightened response to the beta-adrenergic agonist isoproterenol and to hCG, as measured by testosterone secretion. There was however an unexpected capacity of the ovary in vitro to produce cortisol and to secrete it in response to hCG but not to isoproterenol. These data suggest that, during COD, the bovine ovary is under high sympathetic nerve activity that in addition to an increased response to hCG in cortisol secretion could participate in COD development.

Show MeSH
Related in: MedlinePlus