NCI Drug Dictionary

The NCI Drug Dictionary contains technical definitions and synonyms for drugs/agents used to treat patients with cancer or conditions related to cancer. Each drug entry includes links to check for clinical trials listed in NCI's List of Cancer Clinical Trials.

carbon C 11 alpha-methyltryptophan
A radiopharmaceutical containing an analogue of tryptophan, alpha-methyltryptophan (AMT), labeled with carbon 11 (11C), used to measure serotonin synthesis in the human brain using positron emission tomography (PET). Upon administration and once it crosses the blood-brain barrier and into the cytoplasm of serotonergic neurons, carbon C 11 alpha-methyltryptophan acts as a substrate for the enzyme tryptophan hydroxylase and undergoes conversion to carbon C 11 alpha-methyl-5-hydroxytryptophan, also known as C 11 alpha-methyl-serotonin (AMS). C 11 AMS accumulates in serotonergic nerve terminals in proportion to the synthesis rate of serotonin because C 11 AMS cannot be broken down by the enzyme monoamine oxidase, and thus the synthesis rate of serotonin can be imaged using PET. C 11 AMT is not incorporated into proteins, nor are metabolites released into the blood pool, making C 11 AMT an excellent tracer for serotonin synthesis in vivo. Check for active clinical trials using this agent. (NCI Thesaurus)

Abbreviation:[11C] AMT