Charlesworth J A, Williams D G, Naish P, Lachmann P J, Peters D K
Clin Exp Immunol. 1974 Mar;16(3):445-52.
Turnover studies were performed in rabbits using biologically screened, highly purified, radio-labelled human C3 and C3c. Experiments were also carried out using agents known to activate the complement system —cobra venom factor, human nephritic serum and nephrotoxic antibody to rabbit glomerular basement membrane. Activation of labelled C3 by cobra factor provided information regarding the metabolic behaviour of C3d. The fractional catabolic ratio (FCR) of human C3 in normal rabbits was 2·4–2·8% of the plasma pool per hr. FCR for C3c was 4.5% per hr. Activation of C3 consistently resulted in accelerated disappearance of plasma radioactivity. Analysis of the plasma and total body radioactivity curves indicated that both hypercatabolism and extravascular sequestration of radioactivity were responsible for this phenomenon.
利用经过生物学筛选的、高度纯化的、放射性标记的人C3和C3c，在兔身上进行了周转率研究。还使用已知能激活补体系统的试剂进行了实验，这些试剂包括眼镜蛇毒因子、人肾炎血清和抗兔肾小球基底膜的肾毒性抗体。眼镜蛇因子对标记C3的激活提供了有关C3d代谢行为的信息。正常兔中人C3的分解代谢分数率（FCR）为每小时血浆池的2.4 - 2.8%。C3c的FCR为每小时4.5%。C3的激活始终导致血浆放射性加速消失。对血浆和全身放射性曲线的分析表明，放射性的高分解代谢和血管外隔离都是造成这一现象的原因。
