The Effects Of Cyclophosphamide On Platelet Phospholipase A₂ In Infection Model Of Rat

Objective:To explore the effects of cyclophosphamide(CTX) on platelet phospholipase A2(PLA2) in infection model of rat and origin of platelet PLA2 in plasma in the model.Methods: To give a dose (140mg/kg ) of CTX by intraperitoneal injection (i.p.) in day 1. To give Staphylococcus aureus(Sa) by intravenous injection(i.v.) to induce sepsis in day 4. Rat peripheral blood was collected from the abdominalis aorta and organs were obtained just before and 3h after inducing bacterial infection.The changes of bactericidal activities and PLA2 activities of plasma were observed. Platelet PLA2 mRNA was determined by RT-PCR.Results: ( 1 ) Bactericidal activity and platelet PLA2 activity of plasma :After intravenous injection Sa, bactericidal activities decreased 2.8-fold and the platelet PLA2 activity decreased 2.6-fold in rats treated with CTX than that in normal rats(NS). (2) Expression of Platelet PLA2 mRNA in various tissue,organ: Platelet PLA2 mRNA was presented in liver ,spleen, small intestine ,but it was absent in thymus, bone marrow ,blood in CTX group. (3)The changes of WBC and PLT: Level of WBC in CTX group decrease 8-fold than that in normal control group(NS), but level of PLT in CTX group merely decrease 1.1-fold than that in normal control group (NS). level of WBC and PLT in CTX+Sa was slightly higher than those in CTX group,while level of WBC and PLT in NS+Sa was significantly higher than those in NS group.