L-dopa and S-adenosylmethionine.
D000241:Adenosine / Q000097:blood*; D002247:Carbon Isotopes; D004295:Dihydroxyphenylalanine / Q000008:administration & dosage* / Q000494:pharmacology; D006801:Humans; D008715:Methionine / Q000097:blood*; D010300:Parkinson Disease / Q000097:blood* / Q000188:drug therapy; D012436:S-Adenosylmethionine / Q000097:blood; D013997:Time Factors; D014316:Tritium
D002247:Carbon Isotopes; D014316:Tritium; D004295:Dihydroxyphenylalanine; D012436:S-Adenosylmethionine; D008715:Methionine; D000241:Adenosine