Fig. 2.

H₂O₂ production of human PLB 985 cells activated by PMA and inhibited by zinc.

A) In five independent experiments over of 120 min H₂O₂ release was measured. Zinc concentrations from 1 μM to 3 mM inhibited H₂O₂ release. Data is displayed as Mean ± SD. Overall release of H₂O₂ is seen at 120 min. Maximal rate of production is determined at the steepest slope of H₂O₂ release over time. Data was normalized to a single cell (n = 5). B) Dose-response curve giving an IC₅₀ = 33 μM Zn²⁺. C) Dixon Plot fitted with a Michaelis-Menten-Equation showing an apparent K_M =751 μM Zn²⁺. Abbreviations: PLBd = PLB cells differentiated, +PMA = triggered by PMA, +1000 μM Zn²⁺ = 1 mM zinc used to inhibit H₂O₂ release.