INTRODUCTION Reelin (RELN) is an extracellular glycoprotein best known to be crucial for neuronal migration during the embryonic period and regulation of synaptic plasticity in the adult brain, with recent studies pointing to reelin playing an important part in the organization of peripheral organs as well. Abnormalities in RELN function are associated with a variety of medical conditions in human beings. These alterations partly also reflect in RELN's blood levels, which gives it a clinical relevance as a potential biomarker. Requirement for a possible clinical use is a profound understanding of RELN's physiology. We hypothesized blood RELN levels could underlie time-dependent variations and therefore examined individuals' serum reelin concentrations in the course of one day. MATERIAL AND METHODS We obtained blood samples from healthy individuals (n = 10) at several times of measurement over a time period of 24 h. We subsequently determined the respective serum RELN concentrations utilizing an enzyme-linked immunosorbent assay and tested for intra- and interindividual variations in serum RELN concentrations over time. RESULTS All tested individuals' serum RELN levels displayed significant intraindividual variations in the course of 24 h. Test subjects' reelin day profiles showed substantial divergence among each other. CONCLUSIONS Our findings point to short-term fluctuations in blood RELN levels being part of physiological RELN homeostasis. This is of special interest with regard to a potential clinical use of RELN as a biomarker.

中文翻译：

---

健康个体血液卷绕蛋白水平的日内变化。

简介 Reelin (RELN) 是一种细胞外糖蛋白，众所周知，它对于胚胎期神经元迁移和成人大脑突触可塑性的调节至关重要，最近的研究表明，reelin 在外周器官的组织中也发挥着重要作用。RELN 功能异常与人类的多种健康状况有关。这些变化也部分反映在 RELN 的血液水平中，这使其具有作为潜在生物标志物的临床相关性。可能的临床应用的要求是对 RELN 生理学的深刻理解。我们假设血液 RELN 水平可能存在时间依赖性变化，因此检查了个体一天内的血清 reelin 浓度。材料和方法 我们在 24 小时内多次测量，从健康个体 (n = 10) 中获取血液样本。随后，我们利用酶联免疫吸附测定法测定了各自的血清 RELN 浓度，并测试了血清 RELN 浓度随时间的个体内和个体间变化。结果所有测试个体的血清 RELN 水平在 24 小时内均表现出显着的个体差异。测试对象的绕线日概况显示彼此之间存在很大差异。结论 我们的研究结果表明，血液 RELN 水平的短期波动是生理 RELN 稳态的一部分。这对于 RELN 作为生物标志物的潜在临床用途特别重要。