ObjectiveBased on the rat in situ perfusion system, to explore the effect of up-regulating Chemokine (C-X-C motif) receptor 4 (CXCR4) expression on bone marrow neutrophils in modulating its ECC-related rapid release. MethodsTwelve SD rats were randomly divided into fucoidan perfusion group (F, n=6) and control group (C, n=6) after in situ perfusion system establishment. Rats in F group received perfusion of fucoidan solution (total volume 6 ml, 1 h) and C group received buffer only. Femurs from two groups were dissected after one-hour perfusion and bone marrow tissues were collected. The neutrophil CXCR4 expression in two groups were compared using flowcytometry. Eighteen SD rats were randomly divided into fucoidan perfusion group (F', n=6), fucoidan and AMD-3100 perfusion group (F+AMD3100, n=6) and control group (C', n=6) after in situ perfusion system establishment. Rats received desired interventions before stimulation from ECC plasma. After that, 40-min perfusions of buffer were added and total counts of neutrophil in perfusates were compared. ResultsThe percentages of CXCR4 (+) cell and CXCR4 expression fluorescence in F group were 4.71%±0.21% and 161.3±7.8 respectively while the values were 1.11%±0.11% and 58.4±6.5 respectively in C group. Values in F group were both significantly higher than those in C group (P<0.05). The total counts of neutrophil in perfusates from F' group, F+AMD3100 and C' group were 261 393.7±12 470.6, 872 635.2±10 430.6 and 818 675.2±10 708.8, respectively. Statistically differences were observed between each other (P<0.05). ConclusionBone marrow neutrophil CXCR4 expression of SD rat could be effectively up-regulated by perfusion of fucoidan within the in situ perfusion system. ECC-plasma-stimulated bone marrow neutrophil release in rat could be inhibited by fucoidan induced up-regulation of neutrophil CXCR4 expression, and this inhibition effect could be canceled by AMD-3100 intervention.