Convective fluid motion through artery walls aids in transvascular transport of macromolecules. Although many measurements of convective filtration have been reported, they were all obtained under constant transmural pressure. However, arterial pressure in vivo is pulsatile. Therefore experiments were designed to compare filtration under steady and pulsatile pressure conditions. Rabbit carotid arteries were cannulated and excised from male New Zealand white rabbits anesthetized with pentobarbitol sodium (30 mg/kg iv administered). Hydraulic conductance was measured in cannulated excised rabbit carotid arteries at steady pressure. Next, pulsatile pressure trains were applied within the same vessels, and simultaneously, arterial distension was monitored using Optical Coherence Tomography (OCT). For each pulse train, the volume of fluid lost through filtration was measured (subtracting volume change due to residual distension), and compared to that predicted from steady pressure measurements. At 60 and 80 mmHg baseline pressures, the experimental filtration volumes were significantly increased compared to those predicted for steady pressure (p<0.05). Optical Coherence Tomography demonstrated that the excess fluid volume loss was significantly greater than the volume that would be lost through residual distension (p<0.05). After 30 seconds the magnitude of the excess of fluid loss was reduced. These results suggest that sudden onset of pulsatile pressure may cause changes in arterial interstitial hydration.