Imaging of cerebral protein synthesis using [35S]-L-methionine, [1-14C]-L-methionine and [3H-methyl]-L-methionine

Autographic brain imaging techniques using 35S-, 14C-and 3H-labelled L-methionone combined with biochemical measurements of labelled methionine and other amino acids in plasma, the free amino acid pool of the brain, aminoacyl-tRNAs, and proteins have been performed for quantitating protein synthesis rates in rat brain. A model for the metabolic fate of methionine in the brain is presented from which several metabolic pools of the amino acid involved in protein synthesis were determined in the rat tissue. Finally a general reaction model is deduced for the precursor-product relationship in cerebral protein synthesis employing radioactive amino acids. (UK)