Figure 1. Protocol 1. Example of nNOS antagonism and whole-body heat stress.

Two microdialysis sites were used. After an initial normothermic control period when both microdialysis sites were perfused with Ringer solution, both perfusates were changed to 5% DMSO in Ringer solution. Perfusate at one microdialysis site was then changed to a 2 mm solution of 7-NI in 5% DMSO in Ringer solution while 5% DMSO in Ringer solution was maintained at the other site that served as an untreated control. After 30–35 min of perfusion with the 7-NI, skin temperature (T_sk) was decreased to induce whole-body cold stress for 3 min. T_sk was then increased to induce whole-body heat stress for 35–50 min. Finally, subjects were cooled to normothermia and the perfusates at both sites changed to 56 mm nitroprusside to cause maximal vasodilatation.