THE RESPONSES OF SKIN BLOOD-FLOW, MEAN ARTERIAL-PRESSURE AND R-R INTERVAL INDUCED BY COLD STIMULATION WITH COLD WIND AND ICE WATER

This study was designed to evaluate the peripheral circulation respons e to cold wind stimulation. Skin blood flow (SBF), ECG R-R intervals ( RRs) and mean arterial pressure (MAP) were measured in ten healthy men under strictly controlled conditions. Cold wind flow and ice water ba th were prepared as cold stimulations. The subjects were exposed to ea ch cold stimulation and the values of the responses were simultaneousl y recorded. The cold wind stimulation reduced SBF (maximally 40.4 +/- 3.2%) and increased MAP (maximally 106.9 +/- 1.3%), but did not affect RRs. On the other hand, all parameters were affected by the ice water stimulation, which reduced SBF to 16.4 +/- 1.2% and RRs to 85.1 +/- 3 .0%, and increased MAP to 130.6 +/- 2.4% compared with the control sta te. All subjects suffered from intense pain during the ice water but n ot the cold wind stimulation, and two of them were eliminated from thi s study because of vagotonia. After phentolamine iontophoresis was use d to block the receptor of peripheral alpha-adrenergic nerve terminals , the cold wind stimulation did not affect SBF. These results suggest that cold wind stimulation is a useful test for evaluating peripheral cr-adrenergic nerve function in relation to cord sensation, without in crease of RRs and noxious pain.