title: Free tryptophan in serum controls brain tryptophan level and serotonin synthesis.
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism*; D001923:Brain Chemistry; D005215:Fasting; D006897:Hydroxyindoleacetic Acid / Q000032:analysis; D007274:Injections, Intraperitoneal; D008297:Male; D051381:Rats; D012701:Serotonin / Q000032:analysis / Q000096:biosynthesis*; D014364:Tryptophan / Q000008:administration & dosage / Q000032:analysis / Q000097:blood / Q000378:metabolism*; D014462:Ultrafiltration
chemical_list: D012701:Serotonin; D006897:Hydroxyindoleacetic Acid; D014364:Tryptophan