Demonstration of a concanavalin A-induced lymphokine enhancing arginase activity. Effect of presensitization by a skin allograft.
In response to concanavalin A (Con A) mouse spleen cells produce increased amounts of urea. This increase results from arginase activity degrading arginine into urea and ornithine. It is mediated by a soluble protein factor, characterized by its heat stability (10 min at 80 degrees C) and a molecular weight of approximately 32 000. The factor is produced by T cells and acts on a cell population mainly present in bone marrow and spleen. Splenocytes collected from skin allograft recipients during rejection produce more urea in response to Con A than those obtained from normal or syngeneically grafted mice. The maximum urea increase is observed just before and maintained during rejection, declining rapidly thereafter. This phenomenon is explained (a) by a 10-15-fold increase in arginase-enhancing factor production by Con A-stimulated allograft recipient spleen cells and (b) by an increased responsiveness of these splenocytes to the lymphokine.
D000818:Animals; D001119:Arginase / Q000378:metabolism*; D001120:Arginine / Q000378:metabolism; D003208:Concanavalin A / Q000494:pharmacology*; D004261:DNA Replication; D008214:Lymphocytes / Q000187:drug effects / Q000201:enzymology* / Q000276:immunology; D008222:Lymphokines / Q000502:physiology*; D051379:Mice; D008815:Mice, Inbred Strains; D012867:Skin / Q000276:immunology*; D013045:Species Specificity; D013154:Spleen / Q000276:immunology; D014184:Transplantation, Homologous; D014508:Urea / Q000378:metabolism
D008222:Lymphokines; D003208:Concanavalin A; D014508:Urea; D001120:Arginine; D001119:Arginase