Changes in follicular vascularity during the first follicular wave in lactating cows
Changes in follicular vascularity during the first follicular wave in lactating cows
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DOI：
10.1262/jrd.16092
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发表时间：
2005-04-01
影响因子：
1.8
通讯作者：
Miyamoto, A
中科院分区：
文献类型：
--
作者：
Acosta, TJ;Hayashi, KG;Miyamoto, A
单个卵泡的血液供应增加似乎与卵泡生长速度和成为优势卵泡的能力有关，而卵泡膜血管分布减少似乎与卵泡闭锁密切相关。因此，本研究旨在确定周期性荷斯坦奶牛第一卵泡波期间卵泡壁血管分布的实时变化。用经直肠彩色多普勒超声检查（速度灵敏度：> 2 mm / sec）检查正常周期和泌乳奶牛（n=5），以确定卵泡壁的脉管系统（有或无血流）和卵泡直径的变化。在注射PGF（2 α）类似物后48 h注射GnRH诱导新的卵泡波和排卵。注射GnRH后7天每天扫描卵巢。> 2.5 mm的卵泡根据直径变化分为3组：1）最大卵泡，2）第二大卵泡，3）小卵泡，包括所有> 2.5 mm的卵泡。在卵泡选择之前，随后确定的最大和第二大卵泡之间可检测到血流的卵泡百分比没有显著差异。卵泡选择后，第二大卵泡中可检测到血流的卵泡百分比显著降低。此外，从卵泡选择发生前一天开始，可检测到血流的小卵泡比未检测到血流的小卵泡保持更大的直径。这可能是维持卵泡血管系统和适当的血液供应较大的卵泡是至关重要的卵泡优势。在小卵泡中，囊壁内血流的存在似乎也是募集所需的。因此，这些数据表明，在COW中的第一卵泡波中，单个卵泡的血液供应的变化与卵泡生长的动力学密切相关。
Increase in the blood supply to individual follicles appears to be associated with follicular growth rates and the ability to become the dominant follicle, while reduced thecal vascularity appears to be closely associated with follicular atresia. Therefore, this study aimed to determine the real-time changes in the vascularity of the follicle wall during the first follicular wave in cycling Holstein cows. Normally cycling and lactating cows (n=5) were examined by transrectal color Doppler ultrasonography (the sensitivity for velocity: > 2 mm / sec) to determine the changes in the vasculature of the follicle wall (presence or absence of blood flow) and the diameter of follicles. A new follicular wave and ovulation were induced by GnRH injection at 48 h after an injection of PGF(2 alpha) analogue. The ovaries were scanned daily for 7 days after GnRH injection. Follicles > 2.5 mm were classified into 3 groups by the changes in diameter as follows: 1) largest follicle, 2) second largest follicle, and 3) small follicles, which included all other follicles > 2.5 mm. Before the follicle selection, there was no significant difference in the percentage of follicles with detectable blood flow between the subsequently determined largest and second largest follicles. After the follicle selection, the percentage of follicles with detectable blood flow significantly decreased among the second largest follicles. In addition, small follicles with detectable blood flow kept larger diameters than those without detectable blood flow from one day before the occurrence of follicle selection. It is likely that maintenance of follicle vasculature and appropriate blood supply to the larger follicles is essential for follicle dominance. In small follicles, the presence of blood flow within the wall also appears to be required for recruitment. Consequently, the data suggest that the change of the blood supply to an individual follicle closely relates to the dynamics of follicular growth in the first follicular wave in the COW.