Figure 1. Changes in skin blood flow during the venoarteriolar (VA) response and during local administration of phenylephrine at vehicle treated (open bars) and terazosin treated (grey bars) sites.

Inhibition of α₁-adrenoceptors with terazosin did not significantly affect the decrease in skin blood flow associated with the venoarteriolar response. The lack of change in skin blood flow at the terazosin treated site during administration of the α₁-adrenoceptor agonist phenylephrine demonstrates the efficacy of the dose of terazosin at blocking α₁-adrenoceptors. Numbers in parentheses show skin blood flow prior to arm dependency and local administration of phenylephrine.