Fig. 3.

Venous compliance derived from the slope of the pressure-compliance relation in young and older men at baseline and during adrenergic blockade (top). These data indicate that calf venous compliance is reduced in older men compared with young men (before blockade). Moreover, these data suggest that age-associated differences in calf venous compliance are not explained by increased adrenergic influences as age-associated differences persist after adrenergic blockade. Calf venous capacitance (bottom; percent change in calf volume) was determined at the transition between the steep filling and slower plateau phase of changes in calf volume during application of thigh-collecting cuff pressure during the venous compliance trials. Calf venous capacitance is reduced with age in men but was not altered by adrenergic blockade in either young or older men. *P < 0.05 vs. young at the same time point.