A comparative study on the hemolytic action of short asbestos fibers on human, rat, and sheep erythrocytes.

The hemolytic activity of short asbestos fibers isolated by a sedimentation procedure was studied using human (HRBC), rat (RRBC), and sheep (SRBC) red blood cells. The initial velocity (Vi) of hemolysis is proportional to the concentration of fibers with HRBC and RRBC, but not with SRBC. Initial velocity (Vi) is 14.30 for HRBC, 5.75 for RRBC, and 3.60 for SRBC at a concentration of 1,000 micrograms of fibers/ml. Maximum velocity (Vm) is reached at 400 micrograms/ml with HRBC and its value is 16.7. With RRBC and SRBC, Vm is reached at 600 micrograms/ml and its value is 10 and 3.6, respectively. The 50% hemolytic concentration (HC50) at 60 min of incubation is 75 micrograms/ml for HRBC, 240 micrograms/ml for RRBC, and 260 micrograms/ml for SRBC. It appears that the sensitivity against the short asbestos fibers of the three types of RBC used is in the following order: HRBC greater than RRBC greater than SRBC.