Academic Journal
Gonadotropin requirements for dominant follicle selection in GnRH agonist-treated cows
| العنوان: | Gonadotropin requirements for dominant follicle selection in GnRH agonist-treated cows |
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| المؤلفون: | Hampton, J H, Bader, J F, Lamberson, W R, Smith, M F, Youngquist, R S, Garverick, H A |
| المصدر: | Reproduction ; volume 127, issue 6, page 695-703 ; ISSN 1470-1626 1741-7899 |
| بيانات النشر: | Bioscientifica |
| سنة النشر: | 2004 |
| الوصف: | A study was conducted to examine the effects of gonadotropins on ovarian follicular development and differentiation in GnRH agonist (GnRHa)-treated cattle. Holstein cows were allotted into two pre-treatment groups: controls ( n = 5) and GnRHa-treated ( n = 9). Ovaries were removed from control cows on day 5 following a synchronized estrus. Treatment with GnRHa resulted in follicular arrest at <5 mm. Following follicular arrest, GnRHa-treated cows received a constant infusion of FSH for 96 h (GnRHa/FSH), with a randomly selected subset receiving hourly pulses of LH in addition to FSH during the last 48 h of infusion (GnRHa/FSH + LH). At the end of infusion, ovaries were removed, follicles were counted and measured, and follicular fluid samples were collected from large follicles (>10 mm). Differences in expression of mRNA for LH receptor, FSH receptor, cytochrome P450 side-chain cleavage, 3β-hydroxysteroid dehydrogenase, cytochrome P450 17α-hydroxylase (P450c17) and cytochrome P450 aromatase were determined in large follicles using in situ hybridization. The number of large follicles did not differ between GnRHa/FSH-treated and GnRHa/FSH + LH-treated cows ( P = 0.64), but was greater than control animals ( P ≤ 0.004). Follicular fluid concentrations of estradiol-17β and androstenedione were highest in GnRHa/FSH + LH-treated cows ( P ≤ 0.04), intermediate in control cows, and lowest in GnRHa/FSH-treated cows. Hybridization intensity of P450c17 was greater in GnRHa/FSH + LH-treated versus control or GnRHa/FSH-treated cows ( P ≤ 0.03). These results indicate that while FSH can support bovine follicular growth >10 mm, LH increases androgen production and expression of P450c17. |
| نوع الوثيقة: | article in journal/newspaper |
| اللغة: | unknown |
| DOI: | 10.1530/rep.1.00015 |
| الاتاحة: | http://dx.doi.org/10.1530/rep.1.00015 https://rep.bioscientifica.com/view/journals/rep/127/6/1270695.xml https://rep.bioscientifica.com/downloadpdf/journals/rep/127/6/1270695.xml |
| رقم الانضمام: | edsbas.72021206 |
| قاعدة البيانات: | BASE |
| DOI: | 10.1530/rep.1.00015 |
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