Lee V H, Fields P A
University of South Alabama College of Medicine, Department of Structural and Cellular Biology, Mobile 36688.
Biol Reprod. 1991 Aug;45(2):209-14. doi: 10.1095/biolreprod45.2.209.
A porcine relaxin radioimmunoassay was developed to evaluate the profile of immunoreactive relaxin in rabbit plasma. Relaxin was nondetectable in pseudopregnant (Days 1, 4, 5-8, 12, and 16), nonpregnant, and male rabbits. However, in pregnant rabbits, relaxin was detected during the peri-implantation period (Days 4-9). Peak concentrations were reached on Day 15 and were maintained until parturition (Day 32). Relaxin concentrations abruptly decreased on Day 1 postpartum to low but detectable concentrations that were unchanged during the first week postpartum. In contrast, progesterone concentrations peaked earlier (Day 13), decreased after Day 25, and were not detectable on Day 1 postpartum. The effect of ovariectomy on the profile of plasma relaxin was evaluated. Four pregnant rabbits were ovariectomized (Day 13) and treated with medroxyprogesterone acetate to maintain pregnancy. As in normal pregnant rabbits, relaxin was observed initially during the peri-implantation period (Days 4-9) and increased to peak concentrations by Day 16. These concentrations were maintained until parturition and abruptly decreased on Day 1 postpartum to low yet detectable concentrations during the first week postpartum. The concentrations of relaxin in the plasma of ovariectomized medroxyprogesterone-treated rabbits were not different from those in three sham controls. These results indicate that the ovary is not a significant source of relaxin in pregnant rabbits. The unique observation of the presence of relaxin during the peri-implantation period suggests that this hormone has a role in preparing the rabbit uterus for implantation. The continued presence of relaxin during the first week postpartum may represent residual hormone, or it may suggest a physiological role during the early postpartum period.
开发了一种猪松弛素放射免疫分析法，以评估兔血浆中免疫反应性松弛素的情况。在假孕（第1、4、5 - 8、12和16天）、未孕和雄性兔中未检测到松弛素。然而，在孕兔中，在植入前期（第4 - 9天）检测到了松弛素。在第15天达到峰值浓度，并维持到分娩（第32天）。产后第1天松弛素浓度突然下降至低但可检测的浓度，在产后第一周保持不变。相比之下，孕酮浓度在较早时间（第13天）达到峰值，在第25天后下降，产后第1天无法检测到。评估了卵巢切除术对血浆松弛素情况的影响。四只孕兔在第13天进行卵巢切除，并给予醋酸甲羟孕酮以维持妊娠。与正常孕兔一样，最初在植入前期（第4 - 9天）观察到松弛素，并在第16天增加到峰值浓度。这些浓度维持到分娩，并在产后第1天突然下降至低但在产后第一周可检测的浓度。卵巢切除并经醋酸甲羟孕酮处理的兔血浆中松弛素浓度与三只假手术对照兔的浓度无差异。这些结果表明，卵巢不是孕兔松弛素的重要来源。在植入前期存在松弛素这一独特观察结果表明，这种激素在使兔子宫为植入做准备方面发挥作用。产后第一周松弛素持续存在可能代表残留激素，或者可能表明在产后早期有生理作用。
