Rzucidlo S J, Weigl R M, Tilton J E
Department of Animal and Range Sciences, North Dakota State University, Fargo 58105, USA.
Anim Reprod Sci. 1998 May 15;51(3):249-57. doi: 10.1016/s0378-4320(98)00073-6.
Receptors for luteinizing hormone/human chorionic gonadotropin (LH/hCG) have been identified in porcine, rabbit, rat, and human myometrium. To determine the estrous cycle and pregnancy related changes in the receptor capacity and affinity, radioreceptor assays were performed with membrane homogenates of porcine uterine tissues. Cycling gilts were divided into four experimental groups: I (n = 6), day 1-2; II (n = 5), day 6-7; III (n = 5), day 11-12; and IV (n = 6), day 18-20 of the estrous cycle. Pregnant pigs were divided into three experimental groups: I (n = 5), day 35-40; II (n = 5), day 65-70; and III (n = 4), day 95-105 of pregnancy. The concentrations [femtomoles/mg protein (fmol/mg protein)] and affinities of unoccupied LH/hCG binding sites were characterized in all samples of myometrium. Receptor concentrations were highest (P < 0.01) in groups II and III (19.3 +/- 2.5 and 35.8 +/- 2.1 fmol/mg protein, respectively), and was lowest in groups I and IV (5.3 +/- 1.4 and 7.5 +/- 0.7 fmol/mg protein, respectively). Receptor affinity constants (Ka) were consistent (P > 0.05) throughout the estrous cycle [I, (5.1 +/- 1.5) x 10(9); II, (3.0 +/- 0.8) x 10(9); III, (3.2 +/- 0.9) x 10(9); IV, 5.5 +/- 0.7 x 10(9) 1m-1]. Plasma hormone concentrations of progesterone, estrogen and LH were typical of values noted at these times. During pregnancy, receptor concentrations were greatest (P < 0.05) in group II (85.4 +/- 18.5 fmol/mg protein). In groups I and III receptor numbers were 10.8 +/- 2.3 and 26.7 +/- 6.6 fmol/mg protein, respectively. The Ka in group I was 10 times greater (P < 0.05) than Ka in groups II and III, (I, 3.1 +/- 0.9 x 10(10) lm-1; II, 3.4 +/- 0.3 x 10(9) lm-1; III, 3.3 +/- 1.1 x 10(9) lm-1). Plasma hormone concentrations typically found during pregnancy were noted. The function of these LH/hCG binding sites remains unknown; however, changes in receptor capacity during the estrous cycle and pregnancy support a role for modulation of the receptor by hormonal factors.
在猪、兔、大鼠和人类的子宫肌层中已鉴定出促黄体生成素/人绒毛膜促性腺激素（LH/hCG）受体。为了确定发情周期和妊娠期间受体容量和亲和力的相关变化，采用放射受体分析法对猪子宫组织的膜匀浆进行了检测。处于发情周期的后备母猪被分为四个实验组：I组（n = 6），发情周期第1 - 2天；II组（n = 5），发情周期第6 - 7天；III组（n = 5），发情周期第11 - 12天；IV组（n = 6），发情周期第18 - 20天。怀孕母猪被分为三个实验组：I组（n = 5），妊娠第35 - 40天；II组（n = 5），妊娠第65 - 70天；III组（n = 4），妊娠第95 - 105天。对所有子宫肌层样本中未占据的LH/hCG结合位点的浓度[飞摩尔/毫克蛋白质（fmol/mg蛋白质）]和亲和力进行了表征。受体浓度在II组和III组中最高（P < 0.01），分别为19.3±2.5和35.8±2.1 fmol/mg蛋白质，在I组和IV组中最低，分别为5.3±1.4和7.5±0.7 fmol/mg蛋白质。整个发情周期中受体亲和常数（Ka）保持一致（P > 0.05）[I组，(5.1±1.5)×10⁹；II组，(3.0±0.8)×10⁹；III组，(3.2±0.9)×10⁹；IV组，5.5±0.7×10⁹ l/mol]。孕酮、雌激素和LH的血浆激素浓度为这些时期的典型值。在妊娠期间，II组的受体浓度最高（P < 0.05）（85.4±18.5 fmol/mg蛋白质）。I组和III组的受体数量分别为10.8±2.3和26.7±6.6 fmol/mg蛋白质。I组的Ka比II组和III组大10倍（P < 0.05），[I组，3.1±0.9×10¹⁰ l/mol；II组，3.4±0.3×10⁹ l/mol；III组，3.3±1.1×10⁹ l/mol]。记录了妊娠期间通常出现的血浆激素浓度。这些LH/hCG结合位点的功能尚不清楚；然而，发情周期和妊娠期间受体容量的变化支持激素因素对受体的调节作用。
