Nature of the Hemolytic Agent in Previously Irradiated Solutions of Eosine

Abstract

One of us 1 demonstrated that red blood cells are hemolyzed by solutions of fluorescein dyes which have been previously irradiated with the visible portion of sunlight. Finding that such solutions. contained a small concentration of peroxide, 1 and for reasons which seemed consistent with the then known facts of photodynamic action, we assumed that the hemolysis was probably due to the activity of this peroxide, which we suspected of being an organic peroxide. Recently, 2 however, we have offered evidence to show that this peroxide is H₂O₂.

We have determined the quantity of peroxide and dye in solutions which are just capable of producing hemolysis, and have found that mixtures of eosine and H₂O₂ do not produce hemolysis at nearly such low concentrations of these reactants as do irradiated eosine solutions. Table I indicates this discrepancy.

Furthermore, in most cases, we have found that when Na₂S₂O₃ is added to the irradiated solutions in concentrations just equivalent to the concentration of H₂O₂ present, hemolysis is not abolished nor in most cases perceptibly diminished.

An amount of bleaching of the dye solutions occurs which is detectable spectrophotometrically; the quantities are indicated in Table I. We have been forced to conclude that the products of this bleaching, and not peroxide are responsible for at least the greater part of the increased hemolytic properties of our solutions. Further experiments are in progress.