THE EFFECTS OF ALIPHATIC ALCOHOLS ON THE RESPIRATION OF RAT BRAIN CORTEX SLICES AND RAT BRAIN MITOCHONDRIA

Abstract

A study has been made of the effects of a series of aliphatic alcohols (ethanol, n-propanol, isopropanol, n-butanol, and n-pentanol) on the respiration of rat brain cortex slices in the presence or absence of 0.1 M KCl. The respiration of rat brain cortex slices incubated in presence of 0.1 M KCl is found to be much more sensitive to the alcohols than that of the tissue incubated in absence of the added potassium ions. The inhibitory effects of the alcohols increase markedly as the length of the carbon chain increases and with increase of their concentrations. The stimulation of brain cortex respiration by addition of 0.1 M KCl is diminished or abolished by concentrations of the alcohols that have little effect on the unstimulated respiration. n-Pentanol is far more effective than ethanol in effecting an inhibition of potassium-stimulated brain cortex respiration. The inhibitive effects of the alcohols at low concentration on potassium-stimulated brain cortex respiration are not due to a gradual denaturation of tissue proteins. The data point to a rapid establishment of equilibria between the alcohols and components influencing brain respiratory systems. Brain mitochondrial respiration is relatively insensitive to concentrations of alcohols that considerably depress potassium-stimulated respiration of rat brain cortex slices. It is suggested that the alcohols exercise their inhibitory effects on brain cortex respiration at the brain cell membranes.