Presenter : Patricia Choi
Mentor : Christopher Minson
Major : Human Physiology
Poster 2
Currently, the assessment of cutaneous thermal hyperemia is done by locally heating the forearm skin from a baseline of 33 to 42 oC at a rate of 0.1oC/1s. The purpose of this study was to test two different heating protocols from the standard heating protocol. The first heating protocol decreased the target temperature to 39oC compared to the standard heating protocol. The second heating protocol used gradual heating rate of 0.1oC/60s compared to the standard heating proto- col. Four microdialysis fibers were placed in the forearm skin of 16 young healthy subjects. In protocol 1 and 2 (female = 8, male = 8): (1) Control, (2) NO inhibitor, L-NAME (3) KCa channel inhibitor, tetraethylammonium (TEA), and (4) L-NAME +TEA . For both studies, skin sites were locally heated on the forearm from a baseline of 33oC to target temperatures. After maintaining the target temperature for about 40 minutes, the four skin sites were heated to 43.5oC to attain maximal skin blood flow (SkBF). SkBF was measured with Laser Doppler flowmetry. Data are presented as % maximal cutaneous vascular conductance (CVC), which equals blood flow divided by mean arterial pressure. In protocol 1, all drug sites attenuated plateau CVC from the control sites. Compared to the control plateau CVC, there was 80.1 % decrease with L-NAME, close to 77.6% decrease in the L-NAME +TEA site, and 35.2% decrease with TEA. In protocol 2, L-NAME and L-NAME + TEA sites showed attenuated plateau CVC, 29.1% and 32.2% decrease, respectively, compared to the control site.