[Arguments in favor of the extramitochondrial origin of the acetyl radical of acetylcholine synthetized in rat striatum synaptosomes].

Synaptosomes prepared from Rat striatum were loaded with (2-14C) pyruvate at 0 degree C, in the course of a 1 hr. preincubation. When temperature was raised to 37 degrees C, the intra-synaptosomal (2-14C) pyruvate gave rise to 14CO2 but not to (14C) ACh. These results exclude a mitochondrial origin of the acetyl moiety of ACh.