Abstract
Aggregability, sialic acid content and electrophoretic mobility were measured for platelets from 13 gynecological patients 1 day before, 1 day, 1 week and 1 month after laparotomy. Platelet electrophoretic mobility (EPM) was measured by a fully automatic instrument, Laser Zee 3000 system, which determined mean EPM of about 700 platelets with good reproducibility. For all patients, platelet membranes were isolated and their glycoprotein patterns were determined by electrophoresis on SDS-polyacrylamide gels. A significant increase in platelet EPM was observed 1 day after a laparotomy associated with a decrease in platelet count and aggregability. This suggests that a selective consumption of platelets with smaller surface negative charge may occur during postoperative hemostatic plug formation or under surgical stress. In that time, a decrease in sialic acid amount in platelets was observed. A good linear correlation was observed between EPM and sialic acid amount (r=0.856, p<0.001). It suggests that variations in sialic acid content reflect differences of residues which have a direct bearing on the effective surface charge. One day after the laparotomy, a decrease in relative amount of glycoprotein I and increases in glycoprotein II and III (p<0.001-0.005) were observed. There might be an agent which affects the platelet membrane itself or causes a change in the platelet population.
