Flow activates an endothelial potassium channel to release an endogenous nitrovasodilator.
Population
Rabbit iliac arteries and cultured endothelial cells on micro-carrier beads
Design
Preclinical
Authors
Discussion
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Implication
Endothelial KCa-NO axis mediates flow dilation in rabbit arteries; leaves open translation to human coronary physiology or therapy.
Key Points
- This research aims to determine if flow activates a potassium channel in endothelial cells to release nitric oxide, leading to vasodilation.
- Rabbit iliac arteries were perfused at varying flow rates; L,N-mono-methylarginine was used to inhibit nitric oxide synthesis.
- Flow-stimulated endothelial cells were tested for vasodilatory effects in a flow chamber with vascular rings.
- Various antagonists were applied to assess their impact on flow-mediated vasodilation.
- Increased flow led to greater vessel diameter, which was blocked by nitric oxide synthesis inhibitor (L,N-mono-methylarginine).
- Flow-mediated vasodilation was inhibited by barium and KCa channel antagonists (charybdotoxin, iberiotoxin).
- Endothelial cells released a diffusible vasodilator in response to flow, dependent on potassium channel activation.
Structured PICO
P
Population
Rabbit iliac arteries and cultured endothelial cells on micro-carrier beads
I
Intervention
Perfusion at varying flow rates at a constant pressure of 60 mm Hg, with and without various antagonists (e.g., L,N-mono-methylarginine, barium chloride, charybdotoxin, iberiotoxin)
O
Outcome
Flow-mediated vasodilation (changes in vessel diameter) and release of a diffusible vasodilator (nitric oxide)surrogate
Flow-mediated vasodilation is dependent on the activation of an endothelial potassium channel (likely the KCa channel) that leads to the release of nitric oxide.
Cite This Study
Cooke et al. (1991) studied this question.