Suppression of high-pressure-induced hemolysis of human erythrocytes by preincubation at 49 degrees C

When human erythrocytes were preincubated at 37-52 degreesC under atmospher ic pressure before exposure to a pressure of 200 MPa at 37 degreesC, the va lue of hemolysis was constant (about 43%.) up to 45 degreesC but became min imal at 49 degreesC. The results from anti-spectrin antibody-entrapped red ghosts, spectrin-free vesicles, and N-(1-pyrenyl)iodoacetamide-labeled ghos ts suggest that the denaturation of spectrin is associated with such behavi or of hemolysis at 49 degreesC. The vesicles released at 200 mPa by 49 degr eesC-preincubated erythrocytes were smaller than those released by the trea tment at 49 degreesC or 200 mpa alone. The size of vesicles released at 200 mPa was independent of preincubation temperature up to 45 degreesC, and th e vesicles released from 49 degreesC-preincubated erythrocytes became small er with increasing pressure up to 200 mPa. Thus, hemolysis and vesiculation under high pressure are greatly affected by the conformation of spectrin b efore compression. Since spectrin remains intact up to 45 degreesC, the com pression of erythrocytes at 200 mpa induces structural changes of spectrin followed by the release of large vesicles and hemolysis. On the other hand, in erythrocytes that are undergoing vesiculation due to spectrin denaturat ion at 49 degreesC, compression produces smaller vesicles, so that the hemo lysis is suppressed.