Alvarez-Oxiley A V, Sousa N M, Hornick J L, Touati K, van der Weijden G C, Taverne M A M, Szenci O, Sulon J, Debliquy P, Beckers J F
Laboratory of Animal Endocrinology and Reproduction, Faculty of Veterinary Medicine, University of Liege, Liege, Belgium.
Reprod Fertil Dev. 2007;19(7):877-85. doi: 10.1071/rd06173.
Concentrations of bovine placental lactogen (bPL) were determined in fetal plasma samples by twelve double-antibody competitive radioimmunoassay systems (RIA I-XII) based on either recombinant bPL (non-glycosylated) or native bPL (glycosylated). Both preparations were used as standard and tracer, and for primary antisera production. The minimum detection limit measured by these RIA varied from 0.02 to 0.6 ng bPL mL(-1). The coefficients of correlation of different bPL RIA systems were up to 90% (P < 0.0001) when each RIA was tested against the average values of all twelve RIA systems. All developed RIA were used to investigate the incidence of different bPL isoforms in bovine fetal serum samples (n = 71). Fetal concentrations ranged from 11.8 to 35.7 ng mL(-1) at the third month and from 1.1 to 13.5 ng mL(-1) at the ninth month of gestation. They tended to decrease with advancing gestation. In general, those RIA systems that used recombinant bPL as the standard measured higher values than those using the native bPL preparation. These differences decreased toward the end of gestation (P < 0.05), suggesting a lower rate of glycosylation. Our results provide evidence of different glycosylated isoforms of bPL in fetal serum at different gestation periods.
采用12种双抗体竞争性放射免疫分析系统（RIA I - XII），基于重组牛胎盘催乳素（bPL，非糖基化）或天然bPL（糖基化），测定胎儿血浆样本中bPL的浓度。这两种制剂均用作标准品和示踪剂，并用于制备一级抗血清。这些RIA测定的最低检测限为0.02至0.6 ng bPL mL(-1)。当将每种RIA与所有12种RIA系统的平均值进行比较时，不同bPL RIA系统的相关系数高达90%（P < 0.0001）。所有开发的RIA均用于研究牛胎儿血清样本（n = 71）中不同bPL同工型的发生率。妊娠第三个月时胎儿浓度范围为11.8至35.7 ng mL(-1)，妊娠第九个月时为1.1至13.5 ng mL(-1)。它们倾向于随着妊娠进展而降低。一般来说，那些使用重组bPL作为标准品的RIA系统测得的值高于使用天然bPL制剂的系统。这些差异在妊娠末期减小（P < 0.05），表明糖基化率较低。我们的结果提供了不同妊娠期胎儿血清中bPL不同糖基化同工型的证据。
