Relationship between metabolic hormones and ovulation of dominant follicle during the first follicular wave post-partum in high-producing dairy cows
Relationship between metabolic hormones and ovulation of dominant follicle during the first follicular wave post-partum in high-producing dairy cows
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DOI：
10.1530/rep-06-0046
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发表时间：
2007-01-01
期刊：
影响因子：
3.8
通讯作者：
Miyamoto, Akio
中科院分区：
文献类型：
--
作者：
Kawashima, Chiho;Fukihara, Saori;Miyamoto, Akio
最近的研究表明，IGF-I是产后早期卵泡生长的重要调节因子。本研究旨在详细研究高产奶牛产后第一卵泡波优势卵泡（DF）排卵过程中代谢和生殖激素的变化规律。对22头经产荷斯坦奶牛从产前4周至产后3周的血浆相关激素水平进行了测定，并应用彩色多普勒超声观察了DF的发生发展。13头母牛在产后15.2天出现排卵。在围产期期间，无排卵奶牛的GH水平高于有排卵奶牛，IGF-I水平低于有排卵奶牛。每个DF的发展相似，尽管排卵或无排卵，卵泡壁中仍观察到清晰的血流。此外，在22头奶牛中的9头中分析了详细的内分泌特征。5头奶牛显示血浆雌二醇-17 β（E2）随着卵泡生长而增加，随后是E2峰值、LH峰和排卵。在这些奶牛中，血浆IGF-I浓度保持高水平，直至产后10天，随后逐渐下降。随后，胰岛素水平与E2峰值一起增加，朝向排卵。在无排卵奶牛中未观察到这些特征。总之，我们的数据强烈支持IGF-I和胰岛素代表高产奶牛产后卵巢功能恢复的“代谢信号”的概念。此外，我们提供了第一个直观的证据表明，排卵和无排卵的DF的第一卵泡波产后同样提供了活跃的血流。
Recent studies suggest that IGF-I is a crucial regulatory factor in follicular growth during early post-partum period. The aim of the present study was to determine in detail the changing profiles of metabolic and reproductive hormones in relation to ovulation of the dominant follicle (DF) of the first follicular wave post-partum in high-producing dairy cows. Plasma concentrations of related hormones in 22 multiparous Holstein cows were measured from 4 weeks pre-partum to 3 weeks post-partum, and the development of DF was observed with colour Doppler ultrasound. Thirteen cows showed ovulation by 15.2 days post-partum. Anovulatory cows showed higher GH and lower IGF-I levels than those in ovulatory cows during the peri-partum period. Each DF developed similarly, and a clear blood flow in the follicle wall was observed despite ovulation or anovulation. In addition, detailed endocrine profiles were analyzed in 9 out of the 22 cows. Five cows showed an increase in plasma oestradiol-17 beta (E2) with follicular growth followed by E2 peak, LH surge and ovulation. In these cows, plasma IGF-I concentrations remained high until 10 days post-partum followed by a gradual decrease. Subsequently, the insulin level increased together with the E2 peak towards ovulation. These profiles were not observed in anovulatory cows. In conclusion, our data strongly support the concept that IGF-I and insulin represent 'metabolic signals' of the resumption of ovarian function post-partum in high-producing dairy cows. Moreover, we provide the first visual evidence that both ovulatory and anovulatory DFs of the first follicular wave post-partum are similarly supplied with active blood flow.