AbstractsMedical & Health Science

Membrane sulfhydryl (SH) groups have been reported to be important for the maintenance of red cell integrity in vivo (Jacob and Jandl, 1962). A technique has been developed for the determination of reactive membrane sulfhydryl content in intact erythrocytes, utilizing subhemolytic concentrations of p-chloromercuribenzoate (PMB). The erythrocyte membrane of 52 healthy subjects contained 2.50 - 2.85 x 10^-16 moles of reactive SH groups (mean 2.50 +/- 0.20) per erythrocyte, when determined by this method. A 27-36% reduction of erythrocyte membrane SH content was observed in various conditions characterized by accelerated red cell destruction, including glucose- 6-phosphate dehydrogenase (G6PD) deficiency, drug-induced, autoimmune and other acquired hemolytic anemias and congenital spherocytosis. Normal membrane sulfhydryl content was found in iron deficiency anemia, pernicious anemia in relapse, and in other miscellaneous hematological conditions. Inhibition of membrane SH groups with PMB caused marked potassium leakage from the otherwise intact cells. The possible role of membrane sulfhydryl groups in the development of certain types of hemolytic anemias, and in the maintenance of active transmembrane cation transport in the erythrocyte is discussed.