Maruna P, Nedelníková K, Gürlich R
Department of Pathological Physiology, Third Internal Department, Charles University, Prague, Czech Republic.
Physiol Res. 2000;49 Suppl 1:S57-61.
Procalcitonin (PCT), a protein of 116 amino-acids with molecular weight of 13 kDa, was discovered 25 years ago as a prohormone of calcitonin produced by C-cells of the thyroid gland and intracellularly cleaved by proteolytic enzymes into the active hormone. Circulating levels of PCT in healthy subjects are below detection limit. Since 1993 when its elevated level was found in patients with bacterial infection, PCT became an important protein in the detection and differential diagnostics of inflammatory states. The production of PCT during inflammation is linked with a bacterial endotoxin and with inflammatory cytokines (TNF, IL-6). PCT detectable in the plasma during inflammation is not produced in C-cells of the thyroid. The probable site of PCT production during inflammation are the neuroendocrine cells in the lungs or intestine. There is no evidence of plasma PCT binding to cellular receptors of calcitonin, and the role of PCT in calcium and phosphate metabolism during sepsis is still not clear. Other hypothetical roles of PCT (cytokine network regulation, PCT as an endogenous non-steroid antiinflammatory drug) are being considered.
降钙素原（PCT）是一种由116个氨基酸组成、分子量为13 kDa的蛋白质，25年前作为甲状腺C细胞产生的降钙素原激素被发现，并在细胞内被蛋白水解酶切割成活性激素。健康受试者的循环PCT水平低于检测限。自1993年在细菌感染患者中发现其水平升高以来，PCT已成为炎症状态检测和鉴别诊断中的一种重要蛋白质。炎症期间PCT的产生与细菌内毒素和炎性细胞因子（TNF、IL-6）有关。炎症期间血浆中可检测到的PCT并非由甲状腺C细胞产生。炎症期间PCT产生的可能部位是肺或肠道中的神经内分泌细胞。没有证据表明血浆PCT与降钙素的细胞受体结合，脓毒症期间PCT在钙和磷代谢中的作用仍不清楚。PCT的其他假设作用（细胞因子网络调节、PCT作为内源性非甾体抗炎药）正在被考虑。
