Gebarowska D, Ziecik A J, Gregoraszczuk E L
Department of Animal Physiology, Jagiellonian University, Kraków, Poland.
Anim Reprod Sci. 1997 Dec 5;49(2-3):191-205. doi: 10.1016/s0378-4320(97)00060-2.
We used granulosa cells isolated from porcine preovulatory follicles and luteal cells isolated without enzyme dissociation to study the dynamic of changes in human chorionic gonadotropin (hCG) binding parameters (maximum binding capacity B and binding affinity expressed by the equilibrium dissociation constant KD) through the entire luteal phase, paying particular attention to the period between the end of the follicular phase and the beginning of the luteal phase. The oestrous cycle phase was determined by morphological criteria. Five stages of the oestrous cycle were distinguished: (1) preovulatory phase, (2) 1-3 days after ovulation, (3) 5-8 days after ovulation, (4) 8-10 days after ovulation and (5) 12-14 days after ovulation. Highly purified hCG was iodinated and used in radioreceptor assays and autoradiographic studies. Thirty-one autoradiograms from the five distinguished stages of the oestrous cycle were analysed and their optical densities were compared. To establish binding parameters in the five types of cells, 15 Scatchard plots were analysed. There were no statistically significant differences between KD values among all luteal cells (approximately 1.59 +/- 0.39 x 10(-10) mol 1(-1)); however, mean KD in luteal cells was significantly (p < 0.001) lower than KD in granulosa cells (3.38 +/- 0.53 x 10(-10) mol 1(-1). The number of available LH/CG receptors per cell varied with the stage of the luteal phase. There were about 7300 available LH/CG receptors on a single luteal cell isolated from a CL not later than 3 days after ovulation. When the corpora lutea matured, the number of LH/CG receptors per cell increased, reaching approximately 28,400 receptors maximum per cell between the 8th and the 10th day of the luteal phase. Later, when the corpora lutea regressed, the number of receptors fell to 17,400. There were much more LH/CG receptors on granulosa cells than on luteal cells, i.e. 76,600 receptors per granulosa cell. The large number of LH/CG receptors on granulosa cells isolated from preovulatory follicles confirms the key role of LH in transformation of follicles into corpora lutea. The distinctly lower number of these receptors on all types of luteal cells might reflect decreased sensitivity of porcine luteal cells to LH.
我们使用从猪排卵前卵泡中分离的颗粒细胞以及未经酶解离分离的黄体细胞，来研究人绒毛膜促性腺激素（hCG）结合参数（最大结合容量B以及由平衡解离常数KD表示的结合亲和力）在整个黄体期的变化动态，特别关注卵泡期结束至黄体期开始这段时间。发情周期阶段通过形态学标准确定。区分出发情周期的五个阶段：（1）排卵前期，（2）排卵后1 - 3天，（3）排卵后5 - 8天，（4）排卵后8 - 10天，（5）排卵后12 - 14天。高度纯化的hCG进行碘化后用于放射受体分析和放射自显影研究。分析了来自发情周期五个不同阶段的31张放射自显影片，并比较了它们的光密度。为确定五种类型细胞中的结合参数，分析了15个Scatchard图。所有黄体细胞的KD值之间无统计学显著差异（约为1.59±0.39×10⁻¹⁰ mol·L⁻¹）；然而，黄体细胞中的平均KD显著低于颗粒细胞中的KD（p < 0.001）（3.38±0.53×10⁻¹⁰ mol·L⁻¹）。每个细胞上可用的LH/CG受体数量随黄体期阶段而变化。从排卵后不晚于3天的黄体中分离出的单个黄体细胞上约有7300个可用的LH/CG受体。当黄体成熟时，每个细胞上的LH/CG受体数量增加，在黄体期第8天至第10天之间每个细胞最多达到约28400个受体。之后，当黄体退化时，受体数量降至17400个。颗粒细胞上的LH/CG受体比黄体细胞上的多得多，即每个颗粒细胞有76600个受体。从排卵前卵泡中分离出的颗粒细胞上大量的LH/CG受体证实了LH在卵泡转化为黄体过程中的关键作用。所有类型黄体细胞上这些受体数量明显较少可能反映了猪黄体细胞对LH的敏感性降低。
