SCD platelets have inhibited complex V activity. (A) Representative western blots for complexes I, II, IV, and V and integrin αIIb in 3 control and 3 SCD subjects. (B) Densitometric quantification of several such blots in 12 control and SCD platelets. (C) Enzymatic activity of each ETC complex in platelets from SCD patients (black bars) and healthy controls (white bars; n = 15). (D) ATP generation rate in SCD (black bars) and control (white bars) platelets (n = 10 each). (E) Bioenergetic profile (basal and FCCP-induced OCR) for untreated (filled circles) or oligomycin treated (open squares) platelets. (F) ΔΨ and MitoSOX fluorescence intensity of untreated (black bars) or oligomycin-treated (white) healthy platelets (n = 5, *P < .01).