[Effect of chronic morphine administration on concentrations of individual lipids in various rat brain structures]

The effect of morphine administration (for 7 days in the increasing doses of 20 to 40 mg/kg body weight) and its withdrawal (following 1, 3 and 7 days) on the concentrations of lipid fractions in different rat brain regions have been studied. It was found that the drug injected decreased the levels of total lipids and cholesterol in the cortex of the hemispheres and increased cholesterol concentration in the cerebellum. One day after the withdrawal the brain stem showed a decreased amount of cholesterol, its concentration being increased in the cerebellum. Three days after the withdrawal the cerebellum and the hemisphere cortex demonstrated a reduced level of total lipids. Seven days after morphine withdrawal the level of total lipids was diminished in the brain stem, whereas the phospholipids concentration was elevated in the cortex.