Moore L G, Ng Chie W, Hudson N L, McNatty K P
AgResearch Wallaceville Animal Research Centre, Upper Hutt, New Zealand.
J Endocrinol. 2000 May;165(2):185-92. doi: 10.1677/joe.0.1650185.
The glycoprotein hormone FSH comes in many different isoforms. In humans and rats the charges of the FSH isoforms vary with reproductive state and these affect the half-life of FSH in plasma. In this study we examined the charge heterogeneity of FSH in pituitary extracts from sheep with different reproductive states. Also the half-life of clearance of pituitary FSH from the different reproductive states was determined in mice. Pituitaries were collected from: anoestrous, luteal phase, follicular phase, early-pregnant and late-pregnant ewes, ewe lambs, ram lambs, rams during the breeding and non-breeding seasons and wethers (5 per group). After extraction, FSH isoforms were fractionated by HPLC anion exchange chromatography. The volume at which half of the FSH had eluted from the ion exchange column was determined (HP(50)). It was found that FSH isoforms from ewes (HP(50)=96.7+/- 1.3 ml (s.e.m. )) eluted later (P<0.01) than those from rams (HP(50)=82.3+/-1.3 ml) indicating that FSH isoforms in the ewes were more acidic than those from rams. There was a seasonal difference in ewes, with ewes in anoestrus (HP(50)=101.6+/-2.6 ml) having more-acidic (P<0.01) FSH isoforms than the ewes during the oestrous cycle (HP(50)=95.3+/-0.7 ml). There was an effect of age, with the FSH isoforms from cycling ewes (HP(50)=95.3+/- 0.7 ml) being more acidic (P<0.01) than those from ewe lambs (HP(50)=88.3+/-1.9 ml). There was an effect of pregnancy, with late-pregnant ewes (HP(50)=107.3+/- 1.6 ml) having more-acidic FSH isoforms (P<0.05) than those from anoestrous ewes (HP(50)=101.6+/-2.6 ml) and there was an effect of castration with the breeding season rams (HP(50)=80.7+/-1.4 ml) having more-acidic (P<0.05) FSH isoforms than wethers (HP(50)=74.0+/-0.5 ml). The half-life of pituitary FSH from animals in the different reproductive states was found to be negatively correlated with HP(50) (r(2)=0.56, P<0.01). The FSH isoforms from wethers were the least acidic and had the longest half-lives. Collectively, these findings show that in sheep, age, sex and reproductive state are all factors which influence the forms of FSH that are extracted from the pituitary gland. Moreover, these results demonstrate that FSH from sheep with the most-acidic FSH isoforms have the shortest half-life in plasma.
糖蛋白激素促卵泡激素（FSH）有许多不同的亚型。在人类和大鼠中，FSH亚型的电荷随生殖状态而变化，这些变化会影响FSH在血浆中的半衰期。在本研究中，我们检测了处于不同生殖状态的绵羊垂体提取物中FSH的电荷异质性。此外，还测定了不同生殖状态的绵羊垂体FSH在小鼠体内的清除半衰期。垂体取自：乏情期、黄体期、卵泡期、妊娠早期和晚期的母羊、母羊羔、公羊羔、繁殖季节和非繁殖季节的公羊以及去势公羊（每组5只）。提取后，通过高效液相色谱阴离子交换色谱法对FSH亚型进行分离。测定FSH从离子交换柱中洗脱一半时的洗脱体积（HP(50)）。结果发现，母羊的FSH亚型（HP(50)=96.7±1.3 ml（标准误））比公羊的洗脱得更晚（P<0.01）（HP(50)=82.3±1.3 ml），这表明母羊的FSH亚型比公羊的更具酸性。母羊存在季节性差异，乏情期母羊（HP(50)=101.6±2.6 ml）的FSH亚型比发情周期母羊（HP(50)=95.3±0.7 ml）的更具酸性（P<0.01）。年龄也有影响，处于发情周期的母羊（HP(50)=95.3±0.7 ml）的FSH亚型比母羊羔（HP(50)=88.3±1.9 ml）的更具酸性（P<0.01）。妊娠有影响，妊娠晚期母羊（HP(50)=107.3±1.6 ml）的FSH亚型比乏情期母羊（HP(50)=101.6±2.6 ml）的更具酸性（P<0.05），去势也有影响，繁殖季节公羊（HP(50)=80.7±1.4 ml）的FSH亚型比去势公羊（HP(50)=74.0±0.5 ml）的更具酸性（P<0.05）。发现不同生殖状态动物的垂体FSH半衰期与HP(50)呈负相关（r(2)=0.56，P<0.01）。去势公羊的FSH亚型酸性最弱，半衰期最长。总体而言，这些发现表明，在绵羊中，年龄、性别和生殖状态都是影响从垂体中提取的FSH形式的因素。此外，这些结果表明，FSH亚型酸性最强的绵羊的FSH在血浆中的半衰期最短。
