The effects of l-cycloserine on membrane fluidity and lipids of mouse brain

l-Cycloserine can inhibit the synthesis of some sphingolipids, which may play a role in determining membrane fluidity. To evaluate the effects of l-cycloserine on neural cell membranes, adult mice were treated with 100 mg/kg of this drug twice daily for 1, 2, 4, 6, 13 and 17 days. Body weights in the treated mice decreased significantly. Cholesterol and total phospholipid per mass total lipid significantly increased with time. Fluorescence depolarization after the incorporation of diphenylhexatriene into membranes was measured in order to assess membrane fluidity. it increased significantly starting at treatment day 4, with a maximum increase in polarization value of 8%. These results show that l-cycloserine significantly changes the fluidity of brain membrane, but this does not correlate with changes in major lipid classes of the brain.