Limits...
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.

Show MeSH

Related in: MedlinePlus

Incorporation and release of 3H-NE from small antral (SA), preovulatory (PO) and cystic follicular wall. In A is shown the amount of 3H-NE incorporated in follicle wall, In B is shown the release of 3H-NE induced by high potassium depolarization (black rectangles). In A results are expressed as dpm per 50 mg tissue and in B the release is expressed as a percentage of 3H-NE retained in the tissue at each interval studied. The first row upper numbers represent the total release of 3H-NE induced by potassium depolarization and the lower row represents the spontaneous release as percentage of radioactivity released before the depolarization stimulus. *= p < 0.05 vs Small antral (SA) and Preovulatory; & = p < 0.05 vs cystic,
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3117772&req=5

Figure 3: Incorporation and release of 3H-NE from small antral (SA), preovulatory (PO) and cystic follicular wall. In A is shown the amount of 3H-NE incorporated in follicle wall, In B is shown the release of 3H-NE induced by high potassium depolarization (black rectangles). In A results are expressed as dpm per 50 mg tissue and in B the release is expressed as a percentage of 3H-NE retained in the tissue at each interval studied. The first row upper numbers represent the total release of 3H-NE induced by potassium depolarization and the lower row represents the spontaneous release as percentage of radioactivity released before the depolarization stimulus. *= p < 0.05 vs Small antral (SA) and Preovulatory; & = p < 0.05 vs cystic,

Mentions: No changes in the amount of 3H-NE incorporated and retained by the pieces of follicular wall of the different types of follicles were found (Figure 3A) ). The three types of follicles were able to incorporate NE, and they were also able to release NE when a depolarizing stimulus was applied to the preparation (Figure 3B). There was however a decrease of 54% in the amount of 3H-NE released from cystic follicles as compared with SA and PO follicles. It is also interesting to note that basal release, i.e., 3H-NE released spontaneously without stimulation, was 37% higher than in PO follicles.


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)

Incorporation and release of 3H-NE from small antral (SA), preovulatory (PO) and cystic follicular wall. In A is shown the amount of 3H-NE incorporated in follicle wall, In B is shown the release of 3H-NE induced by high potassium depolarization (black rectangles). In A results are expressed as dpm per 50 mg tissue and in B the release is expressed as a percentage of 3H-NE retained in the tissue at each interval studied. The first row upper numbers represent the total release of 3H-NE induced by potassium depolarization and the lower row represents the spontaneous release as percentage of radioactivity released before the depolarization stimulus. *= p < 0.05 vs Small antral (SA) and Preovulatory; & = p < 0.05 vs cystic,
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 3: Incorporation and release of 3H-NE from small antral (SA), preovulatory (PO) and cystic follicular wall. In A is shown the amount of 3H-NE incorporated in follicle wall, In B is shown the release of 3H-NE induced by high potassium depolarization (black rectangles). In A results are expressed as dpm per 50 mg tissue and in B the release is expressed as a percentage of 3H-NE retained in the tissue at each interval studied. The first row upper numbers represent the total release of 3H-NE induced by potassium depolarization and the lower row represents the spontaneous release as percentage of radioactivity released before the depolarization stimulus. *= p < 0.05 vs Small antral (SA) and Preovulatory; & = p < 0.05 vs cystic,
Mentions: No changes in the amount of 3H-NE incorporated and retained by the pieces of follicular wall of the different types of follicles were found (Figure 3A) ). The three types of follicles were able to incorporate NE, and they were also able to release NE when a depolarizing stimulus was applied to the preparation (Figure 3B). There was however a decrease of 54% in the amount of 3H-NE released from cystic follicles as compared with SA and PO follicles. It is also interesting to note that basal release, i.e., 3H-NE released spontaneously without stimulation, was 37% higher than in PO follicles.

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