Figure 4. The role of testosterone and Gas6/Axl in vascular stiffness and blood pressure of aging vessel. (A) Stiffness parameter (β). (B) Pressure-strain elastic modulus (Ep). (C) Distensibility coefficient (DC). (D) Compliance coefficient (CC). (E) Systolic pressure (SBP) and diastolic blood pressure (DSP). (F) Mean arterial pressure (MAP). (G) Pulse pressure (PP). Data are mean ± SD; *P < 0.05, **P < 0.01 and ***P < 0.001 vs. WT young group; †P < 0.05 and ††P < 0.01 vs. WT old group; &P < 0.05, &&P < 0.01 and &&&P < 0.001 vs. Axl-/- young group; #P<0.05 vs. Axl-/- old group; n = 8 for each group.