Regulation of plasminogen activator secretion in mouse peritoneal macrophages. I. - Role of serum studied by a new spectrophotometric assay for plasminogen activators.
A chromogenic tripeptide - H-D-Val-Leu-Lys-p-nitroanilide-substrate of plasmin, can be used to follow plasminogen activation by an activator such as urokinase or the activator secreted by mouse peritoneal macrophages (thioglycolate-elicited). The acceleration of p-nitroaniline production is proportional to the initial rate of plasmin formation from plasminogen. Thus, at a given plasminogen concentration, this acceleration is proportional to the activator concentration. The acceleration can be evaluated from the spectrophotometer trace recording at 405 nm the appearance of p-nitroaniline, either by means of a computer program or by a plot of delta A405 vs.t2. The sensitivity of this assay allows detection of 0.003 CTA units of urokinase. Thioglycollate-elicited mouse peritoneal macrophages secrete plasminogen activator into the extracellular medium during in vitro cultivation only after a contact with serum.
D000818:Animals; D001202:Ascitic Fluid / Q000166:cytology / Q000378:metabolism; D005260:Female; D007700:Kinetics; D008264:Macrophages / Q000378:metabolism*; D051379:Mice; D009842:Oligopeptides; D010960:Plasminogen Activators / Q000378:metabolism*; D013053:Spectrophotometry; D013864:Thioglycolates / Q000494:pharmacology; D014568:Urokinase-Type Plasminogen Activator / Q000494:pharmacology
D009842:Oligopeptides; D013864:Thioglycolates; D010960:Plasminogen Activators; D014568:Urokinase-Type Plasminogen Activator