ABSTRACT
Endogenous peptides, in the form of cytokines, growth hormones and hormone peptides, play an important role in human hormones, nerves, cell growth and reproduction. Neuropeptide is a kind of endogenous peptide, which is related to the physiological activities of pain, sleep, emotion, learning and memory. Neuropeptides exist not only in the nerve cells of the brain, but also in other body fluids and organs. At present, there is still a lack of research on endogenous peptides, especially on neuropeptides. In this study, high-throughput liquid chromatography tandem mass spectrometry was used to identify the distribution of endogenous peptides in the pancreas, heart, liver and kidney as well as the types of neuropeptides. The results showed that the number of endogenous peptides and neuropeptides in the liver was the highest while that of the pancreas was the lowest. The identified endogenous peptides were organ-specific and presented different dynamic distribution in four kinds of organs. The number of LPV (Longest peptide variant) of neuropeptide in the four organs varies greatly, and the distribution of gene family is also different. For example, neuropeptide in pancreas belongs to Glucagon family, while neuropeptide in heart belongs to ACBD7, Granins, PEBP and other families. The identification results will provide reference value for the mechanism study of diseases and the research and development of therapeutic drugs.