alpha1-antitrypsin [Gk, anti, against, trypsin] , a plasma protein produced in the liver that inhibits the action of proteolytic enzymes such as trypsin. Deficiencies are associated with liver disease in children and panacinar emphysema in adults. In the latter, the basic lesion is believed to result from effects of proteolytic enzymes on the walls of the alveoli. Also called antitrypsin, alpha1-proteinase inhibitor.
