Choline Metabolism in Brain

Abstract

Radioactive choline injected intravenously into mice enters the central nervous system by a carrier-mediated transport process. Upon entry into the brain radioactive choline is quickly metabolized to acetylcholine and phosphorylcholine, and in 30 minutes 52% of the radioactivity is converted from a water soluble form to a membranelocalized derivative that is soluble in chloroform. Phenobarbital reduced this pathway by 70%. These studies suggest that acetylcholine and phospholipid metabolism in brain may be dependent upon a rapid choline transport system across the blood-brain barrier. This experimental approach should be useful in studying acetylcholine, phospholipid, and membrane turnover in vivo and may provide more information about the action of drugs in the central nervous system and disorders of membrane excitability and synaptic function. (24:333-339, 1971) Key Words.— Choline; blood brain barrier; phenobarbital; membrane turnover; phospholipid; acetylcholine.