US Environmental Protection Agency, Washington, DC 20460, USA.
Gen Comp Endocrinol. 2011 Feb 1;170(3):650-6. doi: 10.1016/j.ygcen.2010.12.002. Epub 2010 Dec 13.
The objectives of this study were to validate a relaxin and progesterone RIA for use in bottlenose dolphins, and quantify and characterize both hormones in extracts of placental tissue and serum collected during pregnancy and the post-partum period, and compare the results between dolphins with live and stillborn calves. In Experiment 1, validation of a heterologous relaxin and progesterone RIA involved specific displacement of antibody-bound radiolabeled human relaxin or progesterone in response to increasing volumes of pooled pregnant dolphin serum and amounts of respective hormone standards added to a fixed volume of serum. The displacement curves were considered parallel and additive relative to respective standard curves. In Experiment 2, immunoreactive relaxin and progesterone were detected in placental extracts and, in corresponding serum samples, concentrations of both hormones were higher during the pre-partum than post-partum periods. Circulatory concentrations of progesterone decreased (P < 0.05) from relatively high concentrations during early and mid-pregnancy to intermediate concentrations by late pregnancy (month effect, P < 0.0001) in dolphins with live births, whereas, in dolphins with stillbirths, the decrease in progesterone began earlier (month-by-birth status interaction, P < 0.007); mean concentrations were lower at mid- (37%, P < 0.06) and late (25%) pregnancy. Temporally, relaxin increased (P < 0.05) progressively from relatively low concentrations during early pregnancy to high concentrations during late pregnancy (month effect, P < 0.0001) and was not different between birth statuses (birth status effect, P = 0.76; month-by-birth status interaction, P = 0.17). Even though the interaction did not reach significance, mean relaxin concentrations were 42%, 29%, and 34% lower at early, mid-, and late pregnancy, respectively, in dolphins with stillbirths than in those with live births. In conclusion, the pregnancy-specific increase in serum concentrations of relaxin and lower concentrations of both relaxin and progesterone in association with stillbirths suggest the potential for relaxin to be used diagnostically to determine pregnancy status, and one or both hormones to be used to assess placental function, and, perhaps, fetal well-being in bottlenose dolphins and other cetaceans.
本研究的目的是验证一种用于宽吻海豚的松弛素和孕激素 RIA，并定量和表征胎盘组织提取物和妊娠及产后期间采集的血清中的这两种激素，并比较活产和死产海豚之间的结果。在实验 1 中，验证异源松弛素和孕激素 RIA 涉及到在固定体积的血清中，抗体结合的放射性标记人松弛素或孕激素的特异性置换，以响应增加的混合怀孕海豚血清体积和各自激素标准的量。这些置换曲线被认为与各自的标准曲线平行且具有加性。在实验 2 中，在胎盘提取物中检测到免疫反应性松弛素和孕激素，并且在相应的血清样本中，两种激素的浓度在产前阶段都高于产后阶段。在活产海豚中，循环孕酮浓度从妊娠早期和中期的相对高浓度下降（P <0.05），到妊娠晚期的中等浓度（月份效应，P <0.0001），而在死产海豚中，孕酮浓度的下降开始更早（月份-产仔状态交互作用，P <0.007）；中期（37%，P <0.06）和晚期（25%）妊娠的平均浓度较低。从妊娠早期的相对低浓度到妊娠晚期的高浓度，松弛素浓度逐渐增加（P <0.05）（月份效应，P <0.0001），并且在产仔状态之间没有差异（产仔状态效应，P = 0.76；月份-产仔状态交互作用，P = 0.17）。尽管这种相互作用没有达到显著性，但死产海豚在妊娠早期、中期和晚期的平均松弛素浓度分别比活产海豚低 42%、29%和 34%。总之，与死产相关的血清中松弛素浓度的增加以及松弛素和孕激素浓度的降低表明，松弛素具有潜在的诊断价值，可用于确定妊娠状态，并且一种或两种激素可用于评估胎盘功能，以及宽吻海豚和其他鲸目动物的胎儿健康状况。
