Fig. 1.
Schematic representation of local heating protocol. Lactated Ringer’s solution was infused through all fibers for ~60 min to let the hyperemia subside. Sites were then randomly assigned to receive either lactated Ringer’s solution or 20 mM ascorbic acid. In 22 subjects, 2 additional sites were randomized to receive 100 µM apocynin or 10 µM Tempol. Baseline measurements were made at 33°C. After ~30 min, the temperature of the local heaters was increased to 42°C. After a postheating plateau was achieved in all sites, 10 mM NG-nitro-l-arginine methyl ester (l-NAME) was infused through sites. After a post-l-NAME plateau was achieved in all sites, 28 mM sodium nitroprusside (SNP) was infused through all fibers, and the temperature was increased to 43°C to achieve maximal dilation.