An in vitro model for arsine toxicity using isolated red blood cells

A novel test system using isolated red blood cells (RBCs) and arsine (AsH3) in aqueous solution was developed to allow quantitation of AsH3 exposure and to study the toxicity of AsH3 in vitro. In this system AsH3 gas was generated and dissolved in aqueous solution, the concentration was measured, and the standardized solution was mixed with rat or dog red blood cells (RBCs). AsH3 was found to be stable in solution at neutral pH for several hours, but was lost quickly from solution as the acidity was increased to pH 2. Approximately 74% of the initial 0.56 mM AsH3, measured as total arsenic, was found to be taken up by, or strongly associated with, dog RBCs within 5 min of incubation and 82% of the initial 0.49 mM AsH3 was found in rat RBCs after 10 min incubation. Following hypotonic lysis of rat RBCs, 55% of the cell-associated arsenic was found in the membrane fraction with the balance found in the cytosolic fraction. The in vitro technique was used to examine factors influencing AsH3 toxicity using hemolysis as the end point. Hemolysis levels in dog and rat RBC incubations were found to increase with time after exhibiting a lag phase of about 30 min. At the AsH3 concentrations used, maximum levels of hemolysis were observed by 2 hr; maximum hemolysis at room temperature for dog RBCs was 20% and for rat RBCs was 22%. Increasing the temperature from room temperature to 37 degrees C resulted in increased hemolysis in dog RBCs (36%) and rat RBCs (90%).(ABSTRACT TRUNCATED AT 250 WORDS)