Optimization of a comprehensive metabolomic analysis system for characterizing metabolic alterations in the cauda epididymis of mature and juvenile mice

The cauda epididymis protects and stores mature sperm in mammals. Recently, comprehensive transcriptomic and proteomic analyses have been conducted to understand its molecular functions; however, fundamental information on its metabolites has not been reported. In this study, we optimized a system for the comprehensive metabolic analysis of the cauda epididymis in mature and juvenile mice. This system identified 116 and 92 metabolites in mature and juvenile mice, respectively. Comparative analysis revealed that 44 and 13 metabolites were upregulated and downregulated, respectively, in the cauda epididymis of mature and juvenile mice. Based on the identified metabolites, 34 metabolic and unique pathways (mature: four pathways and juvenile: one pathway) were determined. In conclusion, the levels of certain metabolites in the cauda epididymis differed between mature and juvenile mice. These results contribute to understanding of the unique functions of the cauda epididymis based on dynamic changes in metabolites.