Oxyhemoglobin inhibition of acetylcholinesterase activity

The effects of human oxyhemoglobin (HbO2), human methemoglobin (MetHb), and porcine serum albumin (PSA) on the activity of acetylcholinesterase (AChE) isolated from Electrophorus electricus were examined. HbO2 produced a dose-dependent reduction in AChE activity. Fifty percent of activity was obtained at 5 microM HbO2, while 95% inhibition was obtained at 50 microM. In this concentration range MetHb and PSA had little effect on esterase activity.