Laser Doppler flowmetry, a reliable technique for measuring pharmacologically induced changes in cutaneous blood...

Area of Science:

• Physiology
• Biomedical Engineering

Background:

• Laser Doppler flowmetry (LDF) is a non-invasive technique for measuring cutaneous blood flow.
• Reproducibility of resting blood flow measurements using LDF is a known limitation.
• LDF's utility in monitoring pharmacological effects on cutaneous perfusion is under investigation.

Purpose of the Study:

• To evaluate the reproducibility of cutaneous vasomotor reflexes using LDF.
• To assess LDF's potential for short-term drug effect studies.

Main Methods:

• Six healthy subjects participated in the study.
• Measurements were taken at the finger-tip and forearm in the morning and afternoon of the same day.
• Standardized provocation procedures included deep inspiration, Valsalva maneuver, venous occlusion, arterial occlusion with reactive hyperemia, head-up tilting, and cold pressor test.

Main Results:

• Six interventions (deep inspiration, Valsalva, venous occlusion, arterial occlusion, head-up tilting, cold pressor test) induced highly reproducible decreases in total cutaneous blood flow.
• Blood flow reduction was generally more pronounced at the finger-tip, with exceptions like venous occlusion.
• Differences in skin anatomy and function between finger-tip and forearm may explain site-specific responses, such as the absence of reactive hyperemia at the finger-tip.

Conclusions:

• LDF demonstrates excellent reproducibility for resting blood flow and changes induced by standardized provocation tests within the same day.
• LDF appears suitable for short-term investigations of drug effects on cutaneous circulation.
• Long-term day-to-day reproducibility of LDF measurements requires further clarification.