Abstract
Lipoprotein lipase (LPL) secretion by the monocytes obtained from a woman, aged 83, with myelomonocytic leukemia was investigated. LPL activity secreted into the incubation medium by the leukemic monocyte-derived macrophages was detected after 1 day in culture and reached a maximum level at 2 weeks. The rate of the enzyme secretion was enhanced by 2-fold in the presence of heparin. The enzymes both in heparin eluates and in cells required serum for activation and was inhibited by 1M NaCl. The enzyme was retained on the heparin-sepharose column and eluted with 1.5M NaCl.
These results indicate that certain leukemic monocytes can secrete the enzyme which fullfills the criteria for LPL. These cells could be very useful for the cellular study of LPL synthesis and metabolism.
