Suvanto-Luukkonen E, Risteli L, Sundström H, Penttinen J, Kauppila A, Risteli J
Department of Obstetrics and Gynecology, Oulu University Hospital, Finland.
Clin Chim Acta. 1997 Oct 31;266(2):105-16. doi: 10.1016/s0009-8981(97)00140-x.
Postmenopausal hormone replacement therapy (HRT) lowers the turnover rate of the mineralized bone matrix, the predominant organic component of which is type I collagen. The effect of estrogen on bone metabolism has been monitored by measuring the circulating concentration of the carboxy-terminal propeptide of type I procollagen (PICP), which decreases during HRT. We have recently developed assays for the intact amino-terminal propeptide (PINP) of type I procollagen, a protein set free from the other end of the same gene product. PICP and PINP, both derived from the synthesis of type I collagen, but differing in their further metabolism, were assessed in 47 postmenopausal women, aged 45-66 years, undergoing postmenopausal HRT. Estradiol-gel applied daily was combined to a continuous progestin administered by three different routes. Serum samples obtained before the treatment and 6 and 12 months after its commencement were analyzed for PICP, PINP, PINP Col 1 (assay variant measuring also the degradation product of PINP) and PIIINP (amino-terminal propeptide of type III procollagen). During HRT the circulating concentration of PICP decreased by 20%, that of PINP by 42% and that of PINP Col 1 by 32% in 12 months. The correlation between the two propeptides, which was 0.676 before the treatment, increased to 0.851 in 6 months and to 0.815 in 12 months. The correlations between PINP and PINP Col 1 were 0.872 before the treatment and increased to 0.925 and 0.941 after 6 and 12 months of treatment, respectively. The serum concentration of PIIINP, which reflects the turnover of the soft tissue collagens, did not change remarkably. Our findings indicate that the intact PINP is a more dynamic marker of bone metabolism than PICP and can therefore be recommended as a marker reflecting the effect of estrogen on bone collagen formation during HRT.
绝经后激素替代疗法（HRT）可降低矿化骨基质的周转率，其主要有机成分是I型胶原蛋白。通过测量I型前胶原羧基末端前肽（PICP）的循环浓度来监测雌激素对骨代谢的影响，在HRT期间该浓度会降低。我们最近开发了针对I型前胶原完整氨基末端前肽（PINP）的检测方法，该蛋白是从同一基因产物的另一端释放出来的。对47名年龄在45 - 66岁、正在接受绝经后HRT的绝经后女性进行了PICP和PINP的评估，二者均来源于I型胶原蛋白的合成，但进一步代谢情况不同。每日涂抹的雌二醇凝胶与通过三种不同途径给予的连续孕激素联合使用。分析治疗前以及开始治疗后6个月和12个月采集的血清样本中的PICP、PINP、PINP Col 1（也测量PINP降解产物的检测变体）和PIIINP（III型前胶原氨基末端前肽）。在HRT期间，12个月内PICP的循环浓度降低了20%，PINP降低了42%，PINP Col 1降低了32%。两种前肽之间的相关性在治疗前为0.676，6个月时增至0.851，12个月时增至0.815。PINP与PINP Col 1之间的相关性在治疗前为0.872，治疗6个月和12个月后分别增至0.925和0.941。反映软组织胶原蛋白周转率的PIIINP血清浓度没有明显变化。我们的研究结果表明，完整的PINP是比PICP更具动态变化的骨代谢标志物，因此可推荐作为反映HRT期间雌激素对骨胶原形成影响的标志物。
