The Effects of Alcohols in Vitro on the Nervous Cell Membrane Measured by Changes in the (Ca²⁺/Mg²⁺) ATPase Activity and Fluidity of the Synaptosomal Membrane

Abstract

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.

Antifungal activity of alkanols against Zygosaccharomyces bailii and their effects on fungal plasma membrane

“…It is uncertain, however, if the respiratory inhibition mechanism is the primary mode of antifungal action of alkanols against Z. bailii, because we do not know if alkanols can reach the mitochondria in vivo. The results with mitochondria also support the concept of alkanols as nonionic surfactants because enzyme systems related to transport of solutes and electron transfer are located in the inner membrane of the cell envelope (Edelfors and Ravn-Jonsen, 1990). …”

“…On the other hand, n-alkanols increased the fluidity of the nerve plasma membrane affecting (Ca 2+ /Mg 2+ ) ATPase activity (Edelfors and Ravn-Jonsen, 1990). Therefore, the effect of octanol on plasma membrane fluidity was measured.…”

Influence of pyrethroids and piperonyl butoxide on the Ca2+-ATPase activity of rat brain synaptosomes and leukocyte membranes

“…Synaptosomal membranes from brains, except the cerebellum, of male Wistar rats (200 g) were prepared as described by Edelfors and Ravn-Jonsen [17]. The membrane preparation was suspended in 0.32 M sucrose buffer (10 mM imidazole, 1 mM EDTA, pH=7.5) and stored as aliquots at À80 8C until use.…”

Naturally Occurring Antifungal Agents and Their Modes of Action

“…For example, the anesthesia cutoff phenomenon among alkanols is well known and a long standing problem. Anesthesia involves many membrane-bound proteins such as synaptosomal ATPases and acetylcholine receptor (Edelfors and Ravn-Jonsen, 1990;Elliott and Haydon, 1989). The same surfactant concept, disrupting and disorganizing the lipid bilayer-protein interface, seems applicable to explain the anesthesia cutoff phenomena of alkanols.…”