Partitional measurements of circulation can be made between capillaries and arteriovenous anastomoses in the human finger.

We compared the responses of finger blood flow to local and/or whole body warming, as measured by laser Doppler flowmetry (PERIFLUX PF-1d) (LDF), and by venous occlusion plethysmography (BF). The subject's hands were immersed in a bath of water whose temperature (Tw) was initially set at 25 degrees C. The tested hand was kept at about 10 cm above heart level to facilitate the drainage of finger veins during measurement. The ambient temperature (Ta) was initially 20 degrees C. Then, measurements were made under the following conditions on separate days: 1) local hand warming only (LHW), Tw raised from 25 to 40 degrees C; 2) whole body warming only (WBW), Ta was raised from 20 to 35 degrees C; and 3) LHW and WBW combined (CW), LHW (Tw was raised to 35 degrees C and maintained) was followed by WBW. Results showed that both LHW and WBW increased LDF and BF. LDF signals correlated significantly with BF values in each condition (r = 0.932-0.955). However, the slope of the line showing the relationship of LDF and BF, determined by least squares linear regression analysis, was steeper in LHW than in WBW. In CW, the slope showed a bend, creating two different sections in the relationship. Below the bend the relation was steeper and showed a similar slope as that in LHW; above the bend, the relation was more gradual and a similar slope as that in WBW. No such bend was observed in measurements of the forearm skin in CW.(ABSTRACT TRUNCATED AT 250 WORDS)