Red blood cell (RBC) aggregation was investigated in a rat model of se
psis with special emphasis on RBC-related factors. Sepsis was produced
by cecal ligation/ puncture, whereas another group had only laparotom
y (sham operation); blood samples also were obtained from control, uno
perated-on animals, RBC aggregation was measured in autologous plasma
and in 3% dextran 70, 18 hours after the operations, by using a Myrenn
e Aggregometer system and the zeta sedimentation ratio (ZSR) method. R
BC aggregation in autologous plasma was found to be enhanced in both s
ham-operated and septic animals and was consistent with their increase
d plasma fibrinogen levels, However, RBC aggregation in dextran was si
gnificantly higher than control only in the sepsis group, RBCs from se
ptic animals also aggregated more in septic plasma compared with RBCs
from control animals, In the sepsis group, RBC deformability was signi
ficantly decreased, whereas RBC lipid preoxidation was significantly i
ncreased, Our results thus confirm the known increase of RBC aggregati
on in septicemia and, in addition, demonstrate marked alterations of i
ntrinsic RBC properties that further enhance red cell aggregation.