Impact of Rab32 and/or Rab38 inactivation on platelet granule content. (A) Quantification of DG constituents in mouse whole platelet lysates: 5-HT measured by ELISA (left); ADP (middle) and ATP (right) measured by HPLC separation. Results are the mean ± SEM in at least 3 mice; **P < .01, ***P < .0001 using 1-way analysis of variance (ANOVA). (B) Quantification of α granule constituents in mouse whole platelet lysates: PF4 (left) measured by ELISA, P-selectin (middle) and fibrinogen (right) measured by western blotting (mean ± SEM, n = 3; not significant [ns] using Student t test). (C) Quantification of β-hexosaminidase in mouse sera as a measure of lysosome content (mean ± SEM, n = 5, *P < .05 using Student t test).