The purpose of this study is the effect of partial cold-loading on whole body peripheral circulation. The body surface peripheral circulation in 24 cases (25 years old
to 86 years old, the average was 64.3 years) who were suffering coldness, numbness or pain in their feet was examined using Laser-Doppler blood flowmetry. The peripheral
circulation at the base of the 2nd toe of the right foot was estimated after the foot was submerged and cooled for 5 min in a water bath at 20°C (i. e. cold-loading). At the same time, the distant body surface peripheral circulation was estimated at the base of the 2nd finger of the right hand. Simultaneous observations were made of blood flow, blood mass and blood velocity. The peripheral blood flow of the upper
limbs at a room temperature of 20°C (pre-loading) was 5.00 ml/min 100 9 tissue on average. The average blood rnass was 287 and the average blood velocity was 0.516. On the other hand, the average peripheral blood flow of the lower limbs was 2.23, the average blood mass was 149 and the average blood velocity was 0.574. This result shows that the blood flow and blood mass of the upper limbs were more than in the
lower limbs. The average blood flow at the upper limbs decreased to 3.69 from 5.00 (or at 26.2% ) when the lower limbs were submerged and cooled for 5 min in a water
bath at 20°C (i. e. cold-loading). On the other hand, blood flow of the lower limb was 1.51 m l under a condition of cold-loading, and decreased 32.3% from 2.23. Blood mass
of the upper limb was 241 on average and decreased 16.0% from 287. Blood mass of the lower limb was 113 on average and decreased 24.2% from 149. There was no difference between blood velocity of the upper limb under the conditions of room
temperature at 20°C (0.516) and cold-loading (0.501). However, blood velocity of the lower limb increased to 0.642 from 0.574. After the end of cold loading, there was
some tendency for blood flow, blood rnass and blood velocity to return to the amount at pre-loading. Twenty minutes after the end of cold-loading, blood flow increased to 5.74 (14.8% ) compared with pre-loading (5.00). However, blood flow of the lower limb remained at only 83.9% (1.87) of the amount at pre-loading (2.23). These results show that partial cold-loading of the lower limb had a quantitative effect on the distant peripheral circulation. The speculated mechanism of this phenomenon is that it to protects against loosing body heat from the body surface under the conditions of
local cold-loading. Our body has defense mechanisms to decrease whole body peripheral circulation to protect against loosing body heat.
Laser-Doppler blood flowmetry (レーザードプラー血流計)
cold loading (冷水負荷)
peripheral circulation (末梢循環)
blood flow (血流量)
blood velocity (血流速度)