Abstract
When high density lipoproteins (HDL) containing serum amyloid protein A (SAA) were incubated for 3 hr with granulocyte elastase in vitro, SAA were degraded rapidly and almost completely disappeared, but no significant effects were noted to occur for other HDL apoproteins. A high concentration of elastase could also degrade apo C-III protein, though the rate of degradation was lower than that for SAA. SAA in HDL were also catabolized rapidly by polymorphonuclear leucocytes (PMNL) in a manner similar to that by elastase. Elastase, however, degraded SAA more specifically than did PMNL. Aprotinin inhibited the degradation of SAA apoproteins in HDL by elastase and PMNL. This inhibitory effect on SAA degradation was weaker than that on apo C-III degradation.
