Erythrocyte hemolysis and shape changes induced by new lysine-derivate surfactants

The effects of new synthetic lysine-derived anionic surfactants on human an d rat erythrocytes were studied. The surfactants were salts of N-alpha,N-ep silon-dioctanoyl lysine with different counterions: lysine (77KK), tris (tr ishydroxymethyl amminomethane) (77KT), sodium (77KS), and lithium (77KL). 7 7KK and 77KT showed a biphasic hemolytic behavior in the erythrocytes. The surfactants 77KS and 77KL showed concentration-dependent hemolysis with a C H50 of about 3.4 and 2.6 mmol/l, respectively. 77KK and 77KT induced protec tion against hypotonic hemolysis in rat erythrocytes at the concentration w hich showed the least hemolytic activity under isotonic conditions. With hu man erythrocytes, 77KT did not show biphasic behavior in isotonic medium, b ut under hypotonic conditions biphasic behavior was present. Changes in sha pe of the erythrocyte, from discocytic to stomatocytic were observed after incubation with the anionic surfactants studied. Such shape changes occurre d progressively over time, with total alteration in shape occuring after ab out 20 min of incubation. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.