寒気曝露による寒冷血管反応

抄録

Thirty male university students were selected as subjects. Experiments were carried out during the summer at around 3p.m. Each subject in the sitting-resting position inserted his left hand with palm downward and with fingers extended slightly into the cold chamber where the wind (wind velocity of 20cm/sec) blew horizontally from tip of the fingers for 30 min after sitting in a chair at rest for 30 min in the room of 27°C and 70% relative humidity. The skin temperature on the center of the dorsal surface of the distal phalanx of left middle finger was recorded continuously by copper-constantan thermocouple during periods of 5 min before cold exposure, cold exposure and 20 min of recovery.
The results obtained were as follows;
1) The mean values of temperature before cold exposure (T.B.), temperature of first rise after cold exposure (T.F.R.) and time for first temperature rise after cold exposure (T.T.R.) were 34, 3°C, 20.2°C and 6.6 min respectively. The mean values of the mean skin temperature after cold exposure from 20 to 30 min (M.S.T.), the lowest temperature during cold exposure (L.T.) and recovery time (R.T.) were 18.7°C, 15.5°C and 6.5 min respectively. Nine subjects experienced cold pains during cold exposure.
2) Changes in skin temperature during cold exposure and recovery showed great individual variations. The vascular hunting reactions were observed after 20 min in almost all subjects. However a few subjects showed a rapid recovery of skin temperature after initial drop of skin temperature during cold exposure.
3) The higher the T.B., the higher were the T.F.R., M.S.T, and L.T, and the shorter were the T.T.R, and R.T.
4) Cold pains during cold exposure were felt more frequently when T.B, and T.F.R, were low and/or T.T.R, and R.T, were long. All subjects experienced cold pains when T.F.R, was lower than 8°C and T.T.R, was longer than 16 min.