Figure 2.

Effects of UH on fMLP and A23187-induced neutrophil elastase release. (a) A23187 (3 × 10⁻⁸ M) and fMLP (10⁻⁷ M) elicited a similar level of elastase release from neutrophils, both with and without prior priming with TNF-α (10 ng ml⁻¹). UH inhibits this release of elastase (b) in response to fMLP (10⁻⁷ M) but (c) not in response to A23187 (3 × 10⁻⁸ M). Data are expressed as % of control elastase release (fMLP or A23187 without heparin, primed or unprimed cells as appropriate), corrected for basal release under the relevant conditions and represent the mean±s.e.m of experiments with cells from 6 to 8 separate donors, each performed in duplicate. Statistical significance (P<0.05) is indicated (^*) from control release (100%). fMLP, formyl-Met-Leu-Phe; UH, unfractionated heparin.