Also found in: Dictionary, Wikipedia.
Tyr; a naturally occurring amino acid present in most proteins; it is a product of phenylalanine metabolism and a precursor of melanin, catecholamines and thyroid hormones.
an oxidase which converts tyrosine to dopa.
tyrosine tolerance test
used as a test of liver function but about 85% of liver parenchyma must be lost before the test gives a positive reaction.