Endothelial function may be enhanced in the cutaneous microcirculation after a single air dive

Area of Science:

• Physiology
• Vascular Biology
• Diving Medicine

Background:

• Scuba diving's impact on large arteries is known, but microcirculation effects are less understood.
• Existing data suggest distinct responses between large conduit arteries and microcirculation following diving.

Purpose of the Study:

• To investigate changes in cutaneous microcirculation after scuba diving.
• To differentiate the effects of diving on microvascular smooth muscle and endothelial function.

Main Methods:

• Assessed cutaneous microcirculation before and after an air scuba dive (30 min and 24 h post-dive).
• Measured endothelium-dependent (acetylcholine) and independent (sodium nitroprusside) vasomotion.
• Utilized laser Doppler flowmetry to monitor cutaneous blood flux.

Main Results:

• Sodium nitroprusside response (smooth muscle function) was reduced 30 min post-dive but normalized by 24 h.
• Acetylcholine response (endothelial function) showed no significant change at 30 min but was significantly enhanced at 24 h post-dive.

Conclusions:

• Microvascular smooth muscle function is transiently impaired post-scuba diving.
• Microvascular endothelial function is enhanced for up to 24 hours after diving.
• The microcirculation exhibits a different response to diving compared to large conduit arteries.