Analysis of high-pressure-induced disruption of human erythrocytes by flow cytometry

High-pressure-induced hemolysis is suppressed by pretreating human erythrocytes at 49 degrees C, or enhanced by pretreatment with trypsin. So, the response of these pretreated cells to a pressure of 200 MPa was examined using flow cytometry. In the case of intact erythrocytes, a major product was fragmented particles. From 49 degrees C-pretreated cells, vesicles were mainly released. Trypsin-pretreated cells mainly produced open ghosts. Additionally, intact erythrocytes, 49 degrees C-pretreated ones, and trypsin-pretreated ones also released at 200 MPa vesicles of diameter 464 +/- 9, 259 +/- 18, and 574 +/- 16 nm, respectively. These results suggest that mother cells, fragmented particles, vesicles, and open ghosts from 200 MPa-treated erythrocytes are easily monitored by flow cytometry and that the size of released vesicles may also be an important factor in high-pressure-induced hemolysis.