Determination of intracellular and secreted PAI-2 by ELISA.

Ficoll-purified monocytes were isolated by magnetic beads and incubated in 20% autologous serum for 18 hours. Intracellular PAI-2 (A) and secreted PAI-2 (B) were determined in monocytes from 12 probands with low Lp(a) (1), 6 male donors with high Lp(a) (2), control monocytes from 6 probands incubated with 100 μg/mL LDL (3), or with 100 μg/mL purified Lp(a) (4). PAI-2 is given per milligram of total protein. Mean values obtained from 12 (1, 2) or 6 (3, 4) independent determinations in duplicate ± SD are shown. Significance was determined using t test (*P < .05).