Development of an LC–MS/MS assay forquantification of intact INSL3 in rat plasma: supplementary data

Background: Relatively large disulfide-linked polypeptides can serve as signaling molecules for a diversearray of biological processes and may be studied in animal models to investigate their function in vivo.The aim of this work was to develop an LC–MS/MS assay tomeasure a model peptide, INSL3, in rat plasma.Results: A dual enrichment strategy incorporating both protein precipitation and solid phase extractionwas utilized to isolate INSL3 from rat plasma, followed by targeted LC–MS/MS detection. The method wasable to measure full-length INSL3 (6.1 kDa) down to 0.2 ng/ml with acceptable accuracy and precision.Conclusion: The final assay was applied to support an exploratory pharmacokinetic study to evaluatesteady-state concentrations of dosed INSL3 in rat plasma.

背景：相对分子质量较大的二硫键连接多肽可作为多种生物学过程的信号分子，可借助动物模型开展其体内功能研究。本研究旨在开发一种液相色谱-串联质谱（LC–MS/MS）检测方法，用于测定大鼠血浆中的模型多肽胰岛素样肽3（INSL3）。结果：本研究采用蛋白沉淀与固相萃取联用的双重富集策略，从大鼠血浆中分离INSL3，随后通过靶向LC–MS/MS进行检测。该方法可对全长INSL3（分子量6.1 kDa）进行定量，检测下限可达0.2 ng/ml，且具备可接受的准确度与精密度。结论：本研究建立的检测方法已应用于一项探索性药代动力学研究，用以评估给药后大鼠血浆中INSL3的稳态浓度。