Kinetics of amyl nitrite-induced hemoglobin oxidation in cord and adult blood.

The effect of amyl nitrite on the erythrocytes of adult and cord hemoglobin was examined in vitro. This study revealed that amyl nitrite caused oxyhemoglobin to become oxidized to methemoglobin wherein a rectangular hyperbolic curve was generated as the reaction progressed. This curve consisted of a reactionary log phase, and a terminal asymptotic phase only, with no inductionary lag phase. A comparative study of human cord blood oxidation times and adult blood was undertaken. It was revealed that cord blood erythrocytes were oxidized by amyl nitrite at a 5-6-fold greater rate than adult blood erythrocytes. Based on an independent Student's t-test, the time taken for cord blood erythrocytes to undergo oxidation was significantly shorter (P less than 0.05) than adult controls. This greatly enhanced reactivity of cord blood erythrocytes parallels earlier findings when sodium nitrite was used instead of amyl nitrite. However, this difference defies a simple explanation and must be attributed to many factors which may include pH, structural differences, and solubility phenomenon.