THE EFFECTS OF ALCOHOLS INVITRO ON THE NERVOUS CELL-MEMBRANE MEASURED BY CHANGES IN THE (CA-2+/MG-2+) ATPASE ACTIVITY AND FLUIDITY OF THE SYNAPTOSOMAL MEMBRANE

The effect of various alkanols on the central nervous system was studied by using rat brain synaptosomal membranes as an in vitro model. The activity of (Ca2+/Mg2+)ATPase and the membrane fluidity were determined. The n‐alkanols exhibited an increased molar inhibition of the ATPase activity with an increase in the carbon chain length up to 1‐octanol. 1‐octanol and 1‐decanol caused a biphasic effect on the ATPase activity depending on the alkanol concentration, whereas 1‐dodecanol caused a stimulation of the ATPase activity. All alkanols studied caused an increased fluidity of the membrane. Our results indicate that the effect of alkanols on the ATPase activity depends on changes in the border layer between the membrane and the surrounding medium and on a binding of the alkanols to the enzyme molecule. Furthermore, the two‐way effect of 1‐octanol and 1‐decanol and the stimulatory effect of 1‐dodecanol indicate that more mechanisms are involved. In addition, the results indicate that changes in the membrane fluidity do not seem to be a prerequisite of the ATPase inhibition. 1990 Nordic Pharmacological Society