OBJECTIVETo observe the effects of burn serum on the erythropoiesis and granulopoiesis in bone marrow in mice, and to explore the possible underlying mechanism.

METHODSMurine bone marrow cell (BMC) strain was prepared routinely and was employed in the establishment of the culture system of colony forming units of erythrocytes, or granulocytes and monocytes. To both sets of culture system normal murine serum (N group) and burn serum, which was collected from the mice with 15% full thickness burn at 12 postburn hours (PBH) and 1, 3, 5, 7 and 10 postburn days (PBD), (burn serum group) was added. In addition, positive control and blank control groups were set accordingly. The stimulating activity of all kinds of sera on the BMCs in the two sets of culture system was determined. The changes in the burn serum concentrations of EPO and GM-CSF were detected by radioimmunoassay, and the data were analyzed by logarithmic linear fitting correlation with the former influence of burn sera on the erythrocytes and granulocytes.

RESULTS(1) Burn sera exhibited obvious stimulation promoting activity on the erythropoiesis and granulopoiesis in BMC, and the activity peaked (384 +/- 60 and 127 +/- 16 CFU) on 1 PBD and decreased thereafter to approach the values found in normal sera group (125 +/- 14 and 34 +/- 20 CFU) on 7 PBD. (2) The EPO content in burn serum was evidently higher than the normal value (P < 0.01) during 12 PBH to 7PBD period. The GM-CSF concentration was obviously higher than the normal value (P < 0.05) at 12 PBH and on 1 PBD. (3) The EPO concentration in burn serum was significantly and logarithmically correlated with the stimulation promoting activity of burn serum on erythropoiesis (r = 0.8570, P = 0.0137). But the GM-CSF concentration in culture with burn serum was not correlated with the stimulation promoting activity of burn serum on granulopoiesis (r = 0.7049, P > 0.05).

CONCLUSIONThe sera harvested from burned mice during early postburn stage exhibited strong stimulation promoting activity on the erythropoiesis and granulopoiesis in bone marrow. The increased EPO level in burn serum might be the important factor contributing strong stimulation action on erythropoiesis, while increased GM-CSF level was not.