Objective To detect the human neutrophil peptide 1-3（HNP1-3） expression in circadian rhythm.Methods Saliva, peripheral venous blood and gingival crevicular fluid（GCF） samples from mesio-buccal gingival crevice of four first molars of six healthy individuals were collected at two consecutive days from 6∶00 to 22∶00, and the expression of HNP1-3 was detected by enzyme-linked immunosorbent assay（ELISA） method.Results The median in GCF was 5.86 μg·L-1, the overall trend was a sinusoidal waveform, with peak at 14∶00 and valley at 20∶00. The median in saliva was 2.15 μg·L-1, the overall trend was the “V” word waveform, higher in the morning and evening, the valley at 14∶00. The median in peripheral venous blood was 4.79 μg·L-1, the overall trend was single peak waveform, reaching a peak from 6∶00 to 10∶00, and then declining slowly.Conclusion The expression HNP1-3 in saliva, GCF, peripheral venous blood samples existed differences. The trend from high to low was GCF, blood, saliva and showed a certain circadian rhythm.
