Picton H M, Miller A T, Hunter M G
Division of Animal Physiology, School of Biological Sciences, University of Nottingham, Loughborough, UK.
J Reprod Fertil. 1999 Nov;117(2):249-57. doi: 10.1530/jrf.0.1170249.
The aim was to investigate the effect of infusion of purified FSH alone on follicle development in hypogonadotrophic GnRH agonist-treated gilts. Large-White hybrid gilts (n = 12) were treated during the mid-luteal phase and again after 28 days (day 0) with a potent slow releasing GnRH agonist. On day 3, seven gilts were infused for 168 h with 1.5 S1 units oFSH h-1 (equivalent to 1.5 units of bioactivity of NIH-FSH-S1 standard) and blood samples were collected. Ovaries were then recovered and all follicles > or = 1 mm in diameter were dissected and incubated for 2 h in 1 ml Eagle's minimum essential medium. The ovaries were recovered from the remaining five GnRH agonist-treated gilts on day 10 and also from five cyclic gilts during the late follicular phase (controls). Plasma FSH concentrations in GnRH agonist-treated gilts were lower (P < 0.01) than in follicular phase controls, increased (P < 0.001) after 1 h of FSH infusion and reached a plateau similar (P > 0.1) to that of controls after 8 h. Basal LH concentrations were similar (P > 0.1) between GnRH agonist-treated and control gilts and remained unchanged (P > 0.1) throughout the infusion period. GnRH agonist treatment reduced (P < 0.01) basal oestradiol concentrations compared with control gilts. Infusion with FSH alone increased (P < 0.001) plasma oestradiol concentrations after 96 h compared with those before infusion; when the animals were killed oestradiol concentrations were higher (P < 0.01) in GnRH agonist-treated gilts infused with FSH than in controls. This was also apparent by vulval swelling and behavioural oestrus. There were more follicles > or 1 mm in diameter in the GnRH agonist-treated groups than in the controls (184, 153 and 86 per animal; P < 0.01). Infusion with FSH increased the maximum follicle diameter (GnRH agonist: < 4 mm; FSH infused: < 12 mm; controls: < 10 mm) and tended to increase (P < 0.07) the mean number of follicles > or = 6 mm diameter per animal (FSH infused: 53; controls: 21). Total oestradiol production in vitro by follicles > or = 1 mm was higher (P < 0.01) in GnRH agonist-treated gilts infused with FSH and in follicular phase controls than in animals treated with GnRH agonist alone. However, oestradiol and testosterone secretion in vitro per follicle > or = 6 mm in diameter was lower (P < 0.05) in FSH-infused animals than in controls. In summary, although infusion of FSH alone stimulated the growth of multiple follicles of preovulatory size in GnRH agonist-treated gilts, steroidogenic output by individual follicles was impaired.
本研究旨在探讨单独输注纯化促卵泡素（FSH）对促性腺激素释放激素（GnRH）激动剂处理的性腺功能减退后备母猪卵泡发育的影响。选用大白杂交后备母猪（n = 12），在黄体中期及28天后（第0天）用强效缓释GnRH激动剂进行处理。第3天，7头后备母猪以1.5 S1单位FSH·h-1（相当于1.5单位NIH-FSH-S1标准生物活性）持续输注168小时，并采集血样。随后取出卵巢，将所有直径≥1mm的卵泡分离出来，在1ml伊格尔氏最低必需培养基中孵育2小时。在第10天从其余5头经GnRH激动剂处理的后备母猪以及卵泡期后期的5头周期发情母猪（对照组）中取出卵巢。GnRH激动剂处理的后备母猪血浆FSH浓度低于卵泡期对照组（P < 0.01），FSH输注1小时后升高（P < 0.001），8小时后达到与对照组相似的平台期（P > 0.1）。GnRH激动剂处理组和对照组后备母猪的基础促黄体生成素（LH）浓度相似（P > 0.1），在整个输注期间保持不变（P > 0.1）。与对照组相比，GnRH激动剂处理降低了基础雌二醇浓度（P < 0.01）。单独输注FSH 96小时后，血浆雌二醇浓度较输注前升高（P < 0.001）；处死动物时，输注FSH的GnRH激动剂处理后备母猪的雌二醇浓度高于对照组（P < 0.01）。阴户肿胀和行为性发情也表明了这一点。GnRH激动剂处理组直径≥1mm的卵泡数量多于对照组（每头动物分别为184、153和86个；P < 0.01）。输注FSH增加了最大卵泡直径（GnRH激动剂处理组：< 4mm；输注FSH组：< 12mm；对照组：< 10mm），并且每头动物直径≥6mm卵泡的平均数量有增加趋势（P < 0.07）（输注FSH组：53个；对照组：21个）。GnRH激动剂处理且输注FSH的后备母猪以及卵泡期对照组中，直径≥1mm卵泡的体外总雌二醇产量高于单独用GnRH激动剂处理的动物（P < 0.01）。然而，直径≥6mm卵泡的体外雌二醇和睾酮分泌量在输注FSH的动物中低于对照组（P < 0.05）。总之，尽管单独输注FSH可刺激GnRH激动剂处理的后备母猪中多个排卵前大小卵泡的生长，但单个卵泡的类固醇生成能力受损。
