The Effect Of Thromobopoietin On Sepsis Thrombocytopenia Mice

ObjectiveThe morbidity and fatality of the sepsis thrombocytopenia is rising year by year, which threaten our health. Sepsis thrombocytopenia is very common disease in intensive care unit(ICU).About66.7%patient of sepsis may develop thrombocytopenia[1].But the treatment of sepsis thrombocytopenia is still not have some breakthrough. Thrombopoietin (TPO),as the special growth factor of megakaryopoiesis and thrombocytopoiesis, have been successfully used in clinical patient, which are undergoing the chemotherapy of solid tumor and leukaemia. Although there have been reported that TPO have effect for patient of sepsis thrombocytopenia, but the fundamental research is still little. On this basis, we used mice as object of study and the sepsis thrombocytopenia model was induced by lipopolysaccharide(LPS). We investigated the effect of TPO through observing the platelet level, inflammatory factors,born marrow,and the mority. This will supply a novel strategy for the severse disease,which threaten the health of people.MethodThe One hundred SPF C57/BL6mice were all male and the body weigh were18-21g, which were randomized into5grooups:contrl group (C group)(injected with the same dose saline), model group (LPS group)(injected intraperitoneally with LPS30mg/kg),low dose TPO therapy group (L group)(injected intraperitoneally with LPS30mg/kg and daily subcutaneously with TPO4.5ug/kg), middle dose TPO therapy group(M group)(injected intraperitoneally with LPS30mg/kg and daily subcutaneously with TPO9ug/kg), high dose therapy group (H group)(injected intraperitoneally with LPS30mg/kg and daily subcutaneously with TPO18ug/kg), The each group had20mice. TPO was used totally3days. The mice were put to death on the forth day. We observed variation of the peripheral blood platelet and the plasma TNF-a,IL-6,IL-10were detected by enzyme-linked immune sorbent assay(ELISA). The hematopoietic stem cell CD34+and the megakaryocyte CD41/61were detected through flow cytometry(FCM) when the born marrow was got asepticly.The paraffin sections of pulmonary and small bowel were coloured by HE,which could be observed by optical microscope, and then calculate the visceral index after weighing thymus and spleen. The72h mortality of mice was also observed during the study.Result1. The platelet of mice which were treated with LPS was declined as the15-40%of platelet of C group(P<0.01). The platelet level in L group on the first and second day had the same change with that in M group,H group and LPS group(P>0.05). However, on the last two days the platelet level in L group was significant higher than other groups (P<0.01), which was no change in M group and H group compared with LPS group (P>0.05).The nadir platelet level of L group was higher than that of M group, H group and LPS group(P<0.05), but compared with LPS group,which had no rise in M group and H group(P>0.05). On the forth day, the megakaryocyte CD41/61was higher than that of C group(P<0.05).The megakaryocyte CD41/61in L group was more than other groups (P<0.01), which was no change in M group and H group when compared with LPS group(P>0.05). The born marrow hematopoietic stem cell CD34+was also higher in L group(.P<0.05).2. On the forth day, the TNF-a and IL-6level were almost normal in these groups(P>0.05), however, the IL-10level in L group was significant higher than any other group(P<0.01). The thymus index of M group, H group and LPS group were lower than that of C group(P<0.05), which was higher in L group and almost normal(P>0.05). The spleen index was no change in each group(P>0.05). From the aspect of pulmonary pathology, the extent of pathological changes of tissues was alleviate in L group when compared with M group, H group and LPS group. But this was not improved in M group and H group.3. The72h mortality of LPS group, L group, M group,H group were65%,35%,60%,60%, and it was significant lower in L group(P<0.01),which was not improved in M group and H group compared with LPS group(P>0.05).Conclusion 1. Severe thrombocytopenia could induced by LPS.Low dose of TPO had a effect on born marrow proliferation in sepsis thrombocytopenia mice and could increase the nadir platelet, which were not improved with middle and high dose TPO.2. When treated with LPS, the mice would had a poor immunity and damaged lung tissue. Low dose of TPO could improve immunity of sepsis thrombocytopenia mice, increasing the anti-inflammatory cytokine level, partly ameliorating the inflammation, lowering the mortality, which were not improved with middle and high dose TPO.3. The low dose of TPO has a protection to the sepsis thrombocytopenia mice, which may related with the effect on platelet and immunity.4. TPO would not increase the proinflammatory factor in mice of sepsis thrombocytopenia in a short time, but for a long time it need be futher assessed.