Disappearance of free SH-groups in hemoglobin of man, rat and rabbit after exposure to alkylating agents in vitro.

The effect of alkylating agents on the content of free SH-groups in human, rat and rabbit hemoglobin was examined. Treatment of blood in vitro with iodoacetamide, styrene oxide and methyl methanesulfonate resulted in a dose-dependent decrease of free SH-groups in hemoglobin. The free SH-groups of rat hemoglobin were more susceptible to the alkylating agents tested than those of human and rabbit hemoglobin. The method is based on the isolation of hemoglobin and a subsequent measurement of the free SH-content of the hemoglobin by means of a spectrophotometric procedure. This procedure may be useful to examine differences in susceptibility of free SH-groups in hemoglobin, e.g. of different animal species, and on the other hand, to study the potencies of different electrophilic agents to alkylate these nucleophilic centers.