LIVER-ASSOCIATED NATURAL-KILLER ACTIVITY IN CIRRHOTIC RATS

An impaired host defense mechanism is well known in patients with live r cirrhosis (LC), Using a sinusoidal lavage method, lymphocytes were o btained from LC rats that were administered thioacetamide, and natural killer (NK) activity was measured by Cr-51-release assay, The NK cell count was measured by flow cytometric analysis using monoclonal antib ody (Mab) 3.2.3 and/or CD 3-8+ as markers for NK cells, and by immunoh istochemical staining using Mab 3.2.3, Furthermore, interferon (IFN) a was administered to LC rats and the subsequent changes in hepatic NK activity and NK cell count were observed, In the large granular lympho cyte (LGL)-rich fraction (Fr.1, LGLs: 60-90%), the NK activity was sig nificantly lower in the LC rats (40.0 +/- 3.8%) compared to that in th e control rats (48.4 +/- 4.3 %) (P<0.005), In addition, the number of NK cells in the liver tissues of the LC rats was significantly lower c ompared to that in the liver tissues of the control rats by morphometr ic analysis (P<0.05), For LC rats, NK activity of the Fr.1 24 hr after IFN alpha administration (5 x 10(4) IU/100 g body weight) increased s ignificantly (P<0.005), Hepatic NK activity and NK cell count were red uced in the LC rats, and recovered following IFN alpha administration, The results obtained in this study may give clues to better understan ding the impaired host defense mechanism in LC patients.