EXPOSURE OF BLOOD TO VAPORS OR GASES: A NOVEL MODEL WITH BENZENE AS EXEMPLAR

Abstract

An artificial membrane oxygenator has been used to mimic the physiological interface between the blood and vapors or gases, to investigate the toxic effects on blood parameters. The parameter investigated has been the human erythrocyte membrane bound acetylcholinesterase (EMBAChE). The COBE artificial membrane lungs have been used. These artificial lungs are known to support normal pulmonary function during surgery. The artificial lungs were incorporated into a purpose-built circuit designed to mimic the physiological events on exposure of blood to solvent vapor in the lung. This technique allowed blood to circulate at a known rate with a steady flow and to be maintained at 37 C. This provided the means to oxygenate the blood and provide a controlled supply of solvent vapor to the blood. Blood samples over time were taken from the circuit. The EMBAChE was established for these samples. Benzene was used as an example of a toxic solvent vapor. It was found that a statistically significant rise in EMBAChE occurred over a period of 80 min under controlled, benzene in air, flow conditions when compared with the same flow conditions with air alone. The mean concentration of benzene delivered was calculated to be 60.7 ppm / min SEM of 2.7 with a total concentration of benzene approximating 4800 ppm 30% over the 80 min under the flow conditions used. This study shows that the artificial membrane lungs can be a useful tool to investigate the effect of toxic solvent vapors on blood and on human EMBAChE in particular.

Keywords: :

• Artificial Membrane Lung Benzene Human Erythrocyte Membrane-bound Acetylcholinesterase Toxic Vapors