Nett T M, Holtan D W, Estergreen V L
J Reprod Fertil Suppl. 1975 Oct(23):457-62.
Levels of oestrone, equilin and equilenin (E1), oestradiol (E2) LH, PMSG and prolactin were measured by radioimmunoassay in serum from pregnant mares. Levels of E1 were always greater than those of E2. Both E1 and E2 remained at low levels until Day 80, increased significantly (P less than 0-05) by Day 120 to reach peak levels at Day 210 or 240 and then declined until parturition. Maximum levels of oestrogens observed in this study were 828 +/- 151 pg/ml for E1 and 71 +/- 18 pg/ml for E2 at Days 210 and 240 respectively. Spikes of LH release were observed in early pregnancy in most mares. Levels of PMSG were first detectable at Days 32 or 36 and reached a peak of 67-1 i.u./ml 64 days after the last mating. Levels of LH were very low (often non-detectable) from Day 210 of gestation until parturition. Levels of prolactin were extremely variable and showed no clear fluctuating patterns during pregnancy.
采用放射免疫分析法测定了妊娠母马血清中雌酮、马萘雌酮和马萘雌二醇（E1）、雌二醇（E2）、促黄体生成素（LH）、孕马血清促性腺激素（PMSG）和催乳素的水平。E1的水平始终高于E2。E1和E2在第80天之前均维持在低水平，到第120天显著升高（P<0.05），并在第210天或240天达到峰值，随后下降直至分娩。本研究中观察到的雌激素最高水平，E1在第210天为828±151 pg/ml，E2在第240天为71±18 pg/ml。大多数母马在妊娠早期观察到促黄体生成素释放高峰。PMSG水平在第32天或36天首次可检测到，并在最后一次交配后64天达到67.1国际单位/毫升的峰值。从妊娠第210天到分娩，促黄体生成素水平非常低（通常检测不到）。催乳素水平变化极大，在妊娠期间未显示出明显的波动模式。
