Duggavathi R, Bartlewski P M, Agg E, Flint S, Barrett D M W, Rawlings N C
Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada S7N 5B4.
Biol Reprod. 2005 Jun;72(6):1466-74. doi: 10.1095/biolreprod.104.038588. Epub 2005 Mar 2.
We designed three experiments to investigate the relationship between FSH peaks and ovarian follicular waves and to examine whether an endogenous rhythm of FSH peaks exists in sheep. In experiment 1, anestrous ewes were treated with ovine FSH (oFSH) or vehicle (6 ewes per group) at the expected time of an endogenous FSH peak, to double the FSH-peak amplitude in treated ewes. In experiment 2, anestrous ewes were treated with either oFSH or vehicle (6 ewes per group) at the expected time of two consecutive interpeak nadirs, such that the treated ewes had 5 FSH peaks in the time frame of 3 FSH peaks in control ewes. In experiment 3, to measure FSH concentrations, daily blood samples were collected from 5 cyclic ewes for a control period during the estrous cycle and then for three 17-day periods after ovariectomy. Daily blood samples were collected from another group of 8 ovariectomized ewes that were treated with estradiol-releasing implants and intravaginal progestogen sponges. Doubling the FSH-peak amplitude did not alter the characteristics of the following follicular wave. Increasing the frequency of FSH peaks stimulated the emergence of additional follicular waves, but did not alter the rhythmic occurrence of FSH peaks and follicular wave emergence. Endogenous follicular waves in oFSH-treated ewes emerged and grew in the presence of the growing largest follicle of the induced follicular waves. Finally, based on the observation of serum FSH concentrations in ovariectomized ewes, it appears that there exists an endogenous rhythm for peaks in daily serum FSH concentrations, which is, at least in part, independent of regulation by ovarian follicular growth patterns.
我们设计了三个实验，以研究促卵泡素（FSH）峰值与卵巢卵泡波之间的关系，并检验绵羊体内是否存在FSH峰值的内源性节律。在实验1中，在预期的内源性FSH峰值出现时，对处于乏情期的母羊分别用羊促卵泡素（oFSH）或赋形剂进行处理（每组6只母羊），以使处理组母羊的FSH峰值幅度加倍。在实验2中，在预期的两个连续峰间最低点出现时，对处于乏情期的母羊分别用oFSH或赋形剂进行处理（每组6只母羊），从而使处理组母羊在相当于对照组母羊3个FSH峰值的时间范围内出现5个FSH峰值。在实验3中，为了测量FSH浓度，在发情周期的对照期，每天从5只处于发情周期的母羊采集血样，然后在卵巢切除术后的三个17天期间每天采集血样。每天从另一组8只接受释放雌二醇植入物和阴道内孕激素海绵处理的卵巢切除母羊采集血样。将FSH峰值幅度加倍并未改变随后卵泡波的特征。增加FSH峰值的频率刺激了额外卵泡波的出现，但并未改变FSH峰值和卵泡波出现的节律性。在经oFSH处理的母羊中，内源性卵泡波在诱导卵泡波中最大卵泡生长的情况下出现并生长。最后，基于对卵巢切除母羊血清FSH浓度的观察，似乎每日血清FSH浓度峰值存在内源性节律，这至少部分独立于卵巢卵泡生长模式的调节。
