Miller A T, Picton H M, Craigon J, Hunter M G
Department of Physiology and Environmental Science, Sutton Bonington Campus, University of Nottingham, Loughborough, United Kingdom.
Biol Reprod. 1998 Jun;58(6):1372-8. doi: 10.1095/biolreprod58.6.1372.
This study compared the dynamics of follicle development during the follicular phase in Meishan sows (n = 10) with a high ovulation rate, with those in contemporary Large-White hybrid sows (n = 12) (ovulation rates: 27.7 and 17.6, respectively; p < 0.01). Ovaries were recovered on Day 16 or 19 of the cycle, and all follicles > or = 1 mm in diameter were dissected. Fluid was aspirated from all those > or = 2 mm, and the granulosa and theca cells were incubated to estimate aromatase activity and estradiol production. The total number of follicles dissected was higher in Meishan than in Large-White hybrid animals (p < 0.001), and whereas the number decreased (p < 0.01) between Days 16 and 19 in Large-White hybrid sows, there was no significant change in Meishan animals. The mean diameter of Meishan follicles recovered on each of Days 16 and 19 was smaller (p < 0.001) than that of those recovered from Large-White hybrids. Total estradiol production in vitro was higher (p < 0.01) by follicles > or = 2 mm from Meishan sows. There was an interaction (p < 0.01) between day of the cycle, breed, and follicle diameter in aromatase activity in both granulosa cells and theca tissue, and in follicular fluid estradiol concentrations in follicles > or = 2-< 6 mm. The largest three size categories of follicles recovered on Day 19 from each breed were classified as preovulatory (29.0 and 17.7 for Meishan and Large-White hybrid, respectively), and the mean diameter was smaller (p < 0.001) in Meishan animals. Follicular fluid estradiol concentrations and total estradiol synthesis by granulosa and theca combined were higher (p < 0.05) in Meishan than in Large-White hybrid sows. In conclusion, high-ovulating Meishans maintained a higher number of follicles during the follicular phase, which overall synthesized more estradiol in vitro, than did Large-White hybrid animals.
本研究比较了排卵率高的梅山母猪（n = 10）与当代大白杂交母猪（n = 12）（排卵率分别为27.7和17.6；p < 0.01）卵泡期卵泡发育的动态变化。在发情周期的第16天或第19天采集卵巢，解剖所有直径≥1 mm的卵泡。从所有直径≥2 mm的卵泡中抽吸卵泡液，并培养颗粒细胞和卵泡膜细胞以评估芳香化酶活性和雌二醇生成。解剖的卵泡总数梅山母猪高于大白杂交母猪（p < 0.001），大白杂交母猪在第16天至第19天卵泡数量减少（p < 0.01），而梅山母猪则无显著变化。在第16天和第19天采集的梅山卵泡的平均直径均小于从大白杂交母猪采集的卵泡（p < 0.001）。梅山母猪直径≥2 mm的卵泡体外总雌二醇生成量更高（p < 0.01）。在颗粒细胞和卵泡膜组织中的芳香化酶活性以及直径≥2 - < 6 mm卵泡的卵泡液雌二醇浓度方面，发情周期天数、品种和卵泡直径之间存在交互作用（p < 0.01）。从每个品种第19天采集的最大的三类卵泡被归类为排卵前卵泡（梅山和大白杂交母猪分别为29.0和17.7），梅山母猪的平均直径较小（p < 0.001）。梅山母猪卵泡液雌二醇浓度以及颗粒细胞和卵泡膜细胞联合产生的总雌二醇量均高于大白杂交母猪（p < 0.05）。总之，与大白杂交母猪相比，排卵率高的梅山母猪在卵泡期维持了更多数量的卵泡，总体上体外合成了更多的雌二醇。
