【摘要】 为了研究绵羊胚胎期垂体中促性腺激素细胞的发育及功能变化 ,分别在胎儿发育的第 6 0、90、12 0天和出生期采集垂体和血液 ,利用免疫荧光标记和生物学测定方法研究了垂体中促黄体激素 β亚单位 (LH β)的表达和血液中LH生物活性的变化。结果证明 :在胚胎发育的第 6 0天 ,在腺垂体可观察到少量散在的LH β阳性细胞 ;在胎儿发育的 90d ,LH β阳性细胞率显著高于 6 0d(P <0 0 1)时 ,且均匀分布于整个腺垂体 ;在胎儿发育的 12 0d ,LH β阳性细胞率达到高峰 ,但出生期又显著降低。胚胎发育过程中 ,垂体的LH β细胞阳性率与血液中B LH浓度呈现相似的变化趋势 ,且无显著的性别差异。以上研究证明绵羊垂体促性腺激素细胞的功能在胚胎中期之后最活跃 ,在后期垂体中LH β阳性细胞率和血浆B LH浓度都有降低 ,这种波动可能与胎儿垂体 性腺轴的负反馈调节机制的建立有关。更多还原

【Abstract】 In order to determine the ontogeny of the fetal pituitary LH β expression and its relation to the plasma LH β concentrations of the fetuses during gestation, the pituitary glands and blood samples of fetuses and postnatal lambs were collected at day 60, 90, 120 of gestation and the first day after birth, respectively. The expression of pituitary LH β was then detected by immunofluorescences and plasma LH β measured by bioassay (BA). The results demonstratedthat very few scattered LH β immunopositive cells were first detected in the pituitary gland on 60d. By 90d of gestation, there was a significant increase (P<0 01) in the number of LH β immunopositive cell which widely distributed throughout the anterior pituitary gland. However, there was a peak in the number of LH β immunopositive cells at 120 d, which followed by a decline in the new born lamb. The changing pattern of plasma B LH concentrations was similar to the number of LH β immunopositive cells and there was no obvious differences between male and female fetuses, at any age. These results suggest that the proliferation and differentiation of pituitary endocrinal cells occurs before the mid gestation, and the regulating effects of gonadal steroid hormone on the anterior pituitary gland gets matured after the middle stage of the foetal development, although the related mechanisms need to be elucidated further.更多还原