Key Points
- To determine whether endothelin converting enzyme (ECE) activity is present in human hand veins and whether endothelin-1 or big endothelin-1 potentiates sympathetically mediated venoconstriction.
- Administered 90-minute dorsal hand vein infusions of non-systemic endothelin-1 (5 pmol min⁻¹), big endothelin-1 (50 pmol min⁻¹), and 0.9% sodium chloride control in six healthy subjects.
- Measured vein diameter using the Aellig displacement technique and elicited sympathetic venoconstriction using the single deep breath reflex.
- Endothelin-1 induced progressive venoconstriction, reducing hand vein diameter by 49% at 90 minutes (95% CI: -68% to -30%; P = 0.0001).
- Vein diameter did not change significantly with big endothelin-1 (+3%; 95% CI: -11% to +17%; P = 0.0007 vs endothelin-1; P = 0.40 vs baseline) or sodium chloride (+2%; 95% CI: -12% to +16%; P = 0.0002 vs endothelin-1; P = 0.60 vs baseline).
- Venoconstriction evoked by deep breathing was not potentiated by endothelin-1 infusion.
Structured PICO
Does endothelin-1 or big endothelin-1 reduce vein diameter or potentiate sympathetically mediated venoconstriction in healthy subjects?
PPopulation6 healthy subjects
IInterventionDorsal hand vein infusion of local, non-systemic doses of endothelin-1 (5 pmol min-1) and big endothelin-1 (50 pmol min-1) for 90 min
CComparatorDorsal hand vein infusion of sodium chloride (0.9%; w/v) for 90 min
OOutcomeChange in vein diameter at 90 min measured using the Aellig displacement techniquesurrogate
Endothelin-1 is a potent venoconstrictor in human hand veins, but its precursor big endothelin-1 is inactive, suggesting a lack of local endothelin converting enzyme activity in these cutaneous capacitance vessels.