Anti-NSF antibodies inhibited platelet dense-granule secretion in permeabilized human platelets. Platelets with¹⁴C-serotonin-loaded dense granules were preincubated with saponin and 300 μg/mL rabbit IgG purified from preimmune serum (preimm. IgG), anti-NSF IgG from immune serum (anti-NSF) with or without 20 μg/mL recombinant NSF (rNSF). Granule secretion was induced by increasing free Ca²⁺-concentration to 10 μmol/L. Secretion was measured by counting radioactivity in the cell supernatants (see Materials and Methods; mean ± SD, n = 4) The P values were calculated using the paired Student’st-test.