Rutanen E M, Seppälä M, Pietilä R, Bohn H
Placenta. 1984 May-Jun;5(3):243-8. doi: 10.1016/s0143-4004(84)80034-x.
The circulating concentration of placental protein 12 was measured by radioimmunoassay in 109 pregnant women. The effect on the serum PP12 level of temperature, repeat freezing and thawing, and day-to-day and diurnal variation were assessed and the post partum changes of levels were studied. On average, PP12 levels in plasma are about one-half of those in serum in the same individual. PP12 immunoreactivity is destroyed by heating but not by repeated freezing and thawing. Changes in serum PP12 levels at various times of day showed a significant and consistent diurnal variation (F = 7.21; d.f.24; 96; P less than 0.001). The peak mean (+/- s.e.m.) value at 0800 h (80.8 +/- 8.7 ng/ml) was 41 per cent higher than the 24-h mean (P less than 0.05), and the nadir concentration at 1400 h (40.4 +/- 5.4 ng/ml) was 29 per cent lower than the 24-h mean (P less than 0.025). There is also considerable day-to-day variation (up to 72 per cent) in serum PP12 levels. If serum samples are taken at 0700 h, there is a slight negative correlation between PP12 concentration and placental weight (P less than 0.05), but not between PP12 level and birthweight of the child. In term pregnancy, the levels taken at 0700 h are higher (163.7 +/- 12.4 ng/ml) than at 0900 to 1300 h (115.7 +/- 11.4 ng/ml, P less than 0.001). The PP12 level is not affected by labour.(ABSTRACT TRUNCATED AT 250 WORDS)
采用放射免疫分析法对109名孕妇的胎盘蛋白12循环浓度进行了测定。评估了温度、反复冻融以及日间和昼夜变化对血清PP12水平的影响，并研究了产后水平的变化。平均而言，同一个体血浆中的PP12水平约为血清中的一半。PP12免疫反应性会因加热而被破坏，但不会因反复冻融而被破坏。一天中不同时间血清PP12水平的变化呈现出显著且一致的昼夜变化（F = 7.21；自由度24；96；P < 0.001）。08:00时的平均峰值（±标准误）（80.8 ± 8.7 ng/ml）比24小时平均值高41%（P < 0.05），14:00时的最低点浓度（40.4 ± 5.4 ng/ml）比24小时平均值低29%（P < 0.025）。血清PP12水平也存在相当大的日间变化（高达72%）。如果在07:00采集血清样本，PP12浓度与胎盘重量之间存在轻微负相关（P < 0.05），但与胎儿出生体重之间无相关性。足月妊娠时，07:00采集的水平（163.7 ± 12.4 ng/ml）高于09:00至13:00采集的水平（115.7 ± 11.4 ng/ml，P < 0.001）。PP12水平不受分娩影响。（摘要截选至250词）
