Background: Patient with Obstructive sleep apnea (OSA) exposed to chronic intermittent hypoxia (IH), which is thought to be the underlying mechanism that links OSA with cardiovascular disease. However, it remains unclear whether chronic intermittent hypoxia (IH) is associated with in vivo functional impairment in the coronary microvasculature.
Methods and Results: Rats underwent Intermittent Hypoxia (IH) at a rate of 20 cycles per hour (nadir 5% O2 to peak 21% O2 with 0% CO2) for 8 hours per day for up to 3 weeks. Synchrotron cine-angiograms of the coronary vasculatures were recorded using anesthetized after IH. Endothelium-dependent vasodilatory responses in individual coronary vessels were different between control and IH. Furthermore, we investigated streptozotocine-induced diabetic rat underwent IH. Diabetic puls IH animals displayed persisted constrictions during nitric oxide donor (SNP) infusion (P<0.05) and a strong trend toward loss of visible microvessels.
Conclusion: We found that ahead of the clinical reported comparable in coronary endothelial vasodilator function in IH rats. The combination diabetes and IH more acceslates coronary vascular dysfunction and vasoconstriction dependent RhoA activation.