Effect of Hydrogen Peroxide on Neuron Sensitivity to Acetylcholine

The dose-dependent effect of hydrogen peroxide on snail neuromembrane chemosensitivity was studied by means of standard voltage-clamp method. Short-term exposure (7 min) of neurons to H2O2 (10−11–10−4 M) caused dose-dependent depression of Acetylcholine (Ach)-induced ionic currents in the membrane. The H2O2-induced depression of Ach-sensitivity of membrane was more pronounced in K+-free solution than in normal physiological solution and it disappeared in cold medium (5°C). The H2O2 (10−11–10−4 M) decreased membrane electrical conductivity and cell volume. The dose-dependent decrease in Ach-sensitivity of the snail neuromembrane by H2O2 may be due to a decrease in the number of functionally active membrane receptors caused by a decrease in membrane active surface. H2O2-induced decrease in Ach-sensitivity has a metabolic but Na+–K+ pump independent character, the nature of which is the subject for current investigation.