FOLLICULAR DIAMETER, OVULATION RATE, and LH RECEPTOR GENE EXPRESSION IN NELLORE COWS
FOLLICULAR DIAMETER, OVULATION RATE, and LH RECEPTOR GENE EXPRESSION IN NELLORE COWS
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内洛尔奶牛的卵泡直径、排卵率和 LH 受体基因表达
DOI：
10.1071/rdv22n1ab225
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发表时间：
2010
期刊：
影响因子：
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通讯作者：
C. M. Barros
中科院分区：
文献类型：
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作者：
R. A. L. Simões;R. Satrapa;F. S. Rosa;M. Piagentini;A. Castilho;R. L. Ereno;M. Nogueira;J. Buratini;C. M. Barros
本试验的目的是验证卵泡直径、排卵率和LH受体（LHR）亚型基因表达之间的关系，以了解这些方面是否会影响内洛尔奶牛的排卵率。在实验1中，在发情周期的随机阶段（第0天），Nellore奶牛（n = 53）接受孕酮阴道内装置（1.0 g，Primer®，Tecnopec，圣保罗，巴西）和2.5 mg苯甲酸雌二醇（EB; i.m. Estrogin®; Farmavet，巴西圣保罗）。在第8天，PGF 2（150 μ g d-氯前列烯醇; Prolise® ARSA S.R.L.，布宜诺斯艾利斯，阿根廷）进行i.m.装置被移除了器械取出后24小时，对奶牛进行i.m.用EB（1.0 mg），48小时后，用超声波（US; Aloka 900，Tokyo，Japan）测定排卵。排卵后3天，每天通过US观察卵泡生长，根据卵泡直径（mm）将奶牛随机分为3组[G1（7.0 - 8.0）、G2（8.1 - 9.0）和G3（9.1 - 10.0）]，接受6.25 mg LH（i.m.）。Lutropin®-V，Bioniche，贝尔维尔，安大略，加拿大），其相当于初步实验中测定的最小排卵剂量（3.12 mg）的两倍。通过逻辑回归（PROC GEN MOD，SAS Institute，卡里，NC）分析结果。G1、G2和G3的排卵率分别为9（2/21）、36（8/22）和90%（9/10）。当比较G1与G3时，存在显著差异（使用P 1.0比值）。因此，在总共400个卵巢中，分别仅获得A组、B组和C组的5个、4个和4个颗粒层（n = 13）以及7个、8个和8个卵泡膜样本（n = 23）。所得资料以单因子变异数分析及皮尔森相关分析。A、B和C组卵泡膜细胞中总LHR表达（LHR-B3 + LHR-B4 + LHR-B5 + LHR-B6）无显著差异。而在颗粒细胞中，A组卵泡LHR的表达（16.5; mRNA LHR/mRNA GAPD）低于C组（37.6; P <0.05）。LHR-B5和LHR-B6亚型的表达与卵泡直径的增加呈正相关。总之，这些初步结果表明，排卵能力在Nellore牛相关的卵泡直径和颗粒细胞中的LHR表达的增加。R. a. L.西莫埃河a. Satrapa和A. C. S. Castilho是FAPESP（巴西圣保罗）的奖学金和资助的获得者。
The aim of the present experiment was to verify the relationship among follicular diameter, ovulation rate, and gene expression of LH receptor (LHR) isoforms in order to know whether these aspects could or could not influence ovulation rates in Nellore cows. In Experiment 1, at a random stage of the estrous cycle (Day 0), Nellore cows (n = 53) received a progesterone intravaginal device (1.0 g, Primer®, Tecnopec, Sao Paulo, Brazil) and 2.5 mg of estradiol benzoate (EB; i.m. Estrogin®; Farmavet, Sao Paulo, Brazil). On Day 8, PGF2 (150 μg d-cloprostenol; Prolise® ARSA S.R.L., Buenos Aires, Argentina) was administered i.m. and the device was removed. Twenty-four hours after device removal, cows were treated i.m. with EB (1.0 mg) and, 48 h afterwards, ovulation was determined by ultrasonography (US; Aloka 900, Tokyo, Japan). Three days after ovulation, follicular growth was observed daily by US and cows were randomly allocated into 3 groups according to follicular diameter (mm) [G1 (7.0-8.0), G2 (8.1-9.0), and G3 (9.1-10.0)] to receive 6.25 mg of LH (i.m. Lutropin®-V, Bioniche, Belleville, Ontario, Canada), which corresponds to twice the minimum ovulatory dose (3.12 mg) as determined in a preliminary experiment. The results were analyzed by logistic regression (PROC GEN MOD, SAS Institute, Cary, NC). The ovulation rates were 9 (2/21), 36 (8/22), and 90% (9/10) for G1, G2, and G3, respectively. There were significant differences when comparing G1 v. G3 (P 1.0 ratio was used. Therefore, from a total of 400 ovaries, only 5, 4, and 4 granulosa (n = 13) and 7, 8, and 8 theca samples (n = 23) from Groups A, B, and C, respectively, were obtained. The data were analyzed by ANOVA and Pearson’s correlation. There were no significant differences in total LHR expression (LHR-B3 + LHR-B4 + LHR-B5 + LHR-B6) in theca cells from Groups A, B, and C. However, in granulosa cells, follicles from Group A had lower LHR expression (16.5; mRNA LHR/mRNA GAPD) compared with Group C (37.6; P < 0.05). There was a positive correlation between expression of LHR-B5 and LHR-B6 isoforms and an increase in follicular diameter. In conclusion, these preliminary results indicate that ovulatory capacity in Nellore cattle is related to an increase in follicular diameter and LHR expression in granulosa cells. R. A. L. Simoes, R. A. Satrapa, and A. C. S. Castilho are recipients of fellowship and funding from FAPESP (Sao Paulo, Brazil).