Limb venous tone and responsiveness in hypertensive humans

Abstract

animal models demonstrate lower venous compliance as well as increased venous tone and responsiveness compared with normoten-sive (NTN) controls. However, the extent to which findings in exper-imental animals can be extended to humans is unknown. Forearm and calf venous compliance were quantified in 9 NTN (23 1 yr) and 9 HTN (24 1 yr) men at baseline, after administration of nitroglycerin (NTG), during a cold pressor test (CP), and post-handgrip exercise ischemia (PEI). Individual pressure-volume relationships from a cuff deflation protocol (1 mmHg/s) were modeled with a quadratic regres-sion. Regression parameters 1 and 2 were used to calculate com-pliance. A one-way ANOVA was used to compare the beta parameters and a repeated-measures ANOVA was used to compare volumes across all pressures (between groups at baseline and within groups during perturbations). Limb venous compliance was similar betwee