title: Suppression of lymphocyte activation by a protein released from isolated perfused rat liver.
abstract: Isolated rat liver perfusates contain a substance which inhibits 3H-thymidine uptake by phytohemagglutinin-stimulated human peripheral blood lymphocytes in a dose-dependent, noncytotoxic fashion. Suppression is not due to interference of lymphocyte-phytohemagglutinin interaction or dilution of the thymidine pool. Complete inhibition of thymidine uptake is achieved with less than 1.0 microgram of material per ml (which is a potentially achievable concentration in vivo). The release of this material is directly and quantitatively associated with hepatocellular injury as measured by release of glutamic pyruvate transaminase. The material is a highly basic protein with a molecular weight of approximately 65,000 to 80,000 daltons. It is a product of the hepatocyte rather than of nonparenchymal liver cells. Liver-derived materials, such as the presently described molecule, may play a role in in situ regulation of lymphocyte function during immunologically mediated liver disease.
mesh_terms: D000410:Alanine Transaminase / Q000502:physiology; D000818:Animals; D004247:DNA / Q000096:biosynthesis; D066298:In Vitro Techniques; D008099:Liver / Q000276:immunology / Q000502:physiology*; D008213:Lymphocyte Activation; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D010477:Perfusion; D010835:Phytohemagglutinins / Q000378:metabolism; D011506:Proteins / Q000502:physiology*; D051381:Rats; D011917:Rats, Inbred Lew; D013936:Thymidine / Q000378:metabolism
chemical_list: D010835:Phytohemagglutinins; D011506:Proteins; D004247:DNA; D000410:Alanine Transaminase; D013936:Thymidine