title: An in vitro bioassay for leukocytic endogenous mediator(s) using cultured rat hepatocytes.
abstract: Primary cultures of adult rat hepatocytes were used to assay for the presence of leukocytic mediator(s) (LEM), a neutrophil derived protein(s) capable of stimulating the synthesis of acute-phase plasma proteins when injected into rats. In the presence of physiological concentrations of dexamethasone (40 mM), the hepatocytes secreted a variety of plasma proteins as demonstrated by crossed immunoelectrophoresis. The addition of LEM to hepatocytes increased the secretion of several acute-phase related plasma proteins, including fibrinogen and hepatoglobin, and decreased albumin secretion. These results mimic the acute-phase response observed in the intact animal. Fibrinogen secretion was used as a quantitative marker for determining LEM activity. The rate of fibrinogen secretion depended upon both the concentration of dexamethasone and LEM present during a given 24-h assay period. One unit of LEM activity is defined as that concentration of LEM capable of producing a 50% maximal stimulation of fibrinogen secretion.
mesh_terms: D000818:Animals; D001681:Biological Assay; D002478:Cells, Cultured; D003907:Dexamethasone / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D005260:Female; D005340:Fibrinogen / Q000378:metabolism; D007375:Interleukin-1; D008099:Liver; D008297:Male; D009504:Neutrophils / Q000032:analysis*; D011506:Proteins / Q000032:analysis* / Q000494:pharmacology; D011817:Rabbits; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D007375:Interleukin-1; D011506:Proteins; C008270:leukocyte endogenous mediator; D003907:Dexamethasone; D005340:Fibrinogen