Nishimoto Hiromi, Hamano Seizo, Hill Glen Alan, Miyamoto Akio, Tetsuka Masafumi
Department of Life Science and Agriculture, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Japan.
J Reprod Dev. 2009 Apr;55(2):219-24. doi: 10.1262/jrd.20114. Epub 2009 Feb 5.
A simple and clear means to identify the physiological status of follicles is essential for study of follicular biology. In the present study, we verified a novel classification procedure based on analysis of the follicular population and glucose concentration in follicular fluid (FF) as an alternative method to classify bovine follicles. Paired ovaries were collected from heifers, and the number of follicles and stage of the CL were recorded. Follicles were initially divided into the following 3 groups according to diameter and the ratio of E2 and P4 (E/P): E2 active (E-A: E/P>or=1), E2 inactive (E-I: E/P<1, >or=8.5 mm) and small follicles (E/P<1, <8.5 mm). E-A follicles were easily identified as E2-rich dominant follicles and were further classified according to diameter and stage of the CL as early dominant (EDF: <8.5 mm), dominant (DF: >or=8.5 mm, stages I-III) or preovulatory follicles (POF: >or=8.5 mm, stage IV). E-I follicles were classified as follows based on the status of the accompanying follicles: early atretic (EAF: without an E-A follicle), mid-atretic (MAF: with an EDF or DF) and late atretic follicles (LAF: with an EAF or POF). The follicular P4 concentrations of the MAF and LAF were significantly higher compared with that of the EAF, while follicular glucose concentration of the LAF was lower compared with those of EAF and MAF, indicating that this classification can be used to distinguish early atretic follicles from more advanced atretic follicles. Small follicles were classified as growing (GF: without E-A follicles) and suppressed small follicles (SSF: with E-A follicles). The SSF was easily identifiable by this procedure, but some GF populations likely contained SSF. To identify true GF, the ratio of E2 in the GF and accompanying EAF may be used. In conclusion, analysis of the follicular population in conjunction with biochemical indices such as steroid and glucose concentrations in FF provides a simple and accurate means of classifying bovine follicles.
一种简单明了的识别卵泡生理状态的方法对于卵泡生物学研究至关重要。在本研究中，我们验证了一种基于卵泡群体分析和卵泡液（FF）中葡萄糖浓度的新型分类程序，作为一种对牛卵泡进行分类的替代方法。从后备母牛收集配对的卵巢，并记录卵泡数量和黄体阶段。卵泡最初根据直径以及E2和P4的比例（E/P）分为以下3组：E2活跃（E-A：E/P≥1）、E2不活跃（E-I：E/P＜1，≥8.5mm）和小卵泡（E/P＜1，＜8.5mm）。E-A卵泡很容易被识别为富含E2的优势卵泡，并根据直径和黄体阶段进一步分类为早期优势卵泡（EDF：＜8.5mm）、优势卵泡（DF：≥8.5mm，I-III期）或排卵前卵泡（POF：≥8.5mm，IV期）。E-I卵泡根据伴随卵泡的状态分类如下：早期闭锁卵泡（EAF：无E-A卵泡）、中期闭锁卵泡（MAF：有EDF或DF）和晚期闭锁卵泡（LAF：有EAF或POF）。MAF和LAF的卵泡P4浓度显著高于EAF，而LAF的卵泡葡萄糖浓度低于EAF和MAF，表明这种分类可用于区分早期闭锁卵泡和更晚期的闭锁卵泡。小卵泡分为生长卵泡（GF：无E-A卵泡）和受抑制的小卵泡（SSF：有E-A卵泡）。通过该程序很容易识别出SSF，但一些GF群体可能包含SSF。为了识别真正的GF，可以使用GF中E2与伴随的EAF的比例。总之，结合卵泡群体分析以及FF中的类固醇和葡萄糖浓度等生化指标，为牛卵泡分类提供了一种简单而准确的方法。
