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. Author manuscript; available in PMC: 2009 Oct 1.
Published in final edited form as: Biochim Biophys Acta. 2008 Aug 5;1781(10):643–654. doi: 10.1016/j.bbalip.2008.07.005

Fig. 4.

Fig. 4

Carboxylesterase activity in THP-1 cell lysate is inhibited by paraoxon treatments. (A) THP-1 cell lysate was incubated with paraoxon for 30 min at 37°C at various concentrations. Carboxylesterase activity toward para-nitrophenyl valerate is expressed as % of control (mean ± SD, n = 3). (B) THP-1 cell lysate was boiled (control), treated with ethanol vehicle (no inhib), or treated with 10 μM paraoxon (PO) for 10 min before incubation with 75 μM cholesteryl [1-14C]oleate. CEH specific activities are expressed as means ± SEM (n = 9–17 individual reactions per group). As a comparison, porcine bile-salt stimulated cholesterol esterase (0.2 units/reaction), which was used as a positive control for the CEH assay, yielded ~17-fold greater CEH activity than THP-1 cell lysates (no inhib), even without added bile salts (data not shown).