Effect of ATP-Sensitive Potassium Channel Inhibition on Resting Coronary Vascular Responses in Humans

• Published in: Circulation research 2002-02, Vol.90 (2), p.231-236
• Main Authors: Farouque, H. M Omar, Worthley, Stephen G, Meredith, Ian T, Skyrme-Jones, R Andrew P, Zhang, Michael J
• Format: Article
• Language: English
• Subjects: Adenosine - pharmacology; Adenosine Triphosphate - metabolism; Biological and medical sciences; Blood Flow Velocity - drug effects; Blood Glucose - drug effects; Coronary Angiography; Coronary Artery Disease - complications; Coronary Artery Disease - metabolism; Coronary Circulation - drug effects; Coronary Vessels - drug effects; Coronary Vessels - metabolism; Diabetes Mellitus, Type 2 - complications; Diabetes Mellitus, Type 2 - metabolism; Dose-Response Relationship, Drug; Electrocardiography - drug effects; Female; Fundamental and applied biological sciences. Psychology; Glyburide - administration & dosage; Glyburide - adverse effects; Heart; Humans; Hypoglycemic Agents - administration & dosage; Hypoglycemic Agents - adverse effects; Infusions, Intra-Arterial; Insulin - blood; Male; Microcirculation - drug effects; Middle Aged; Potassium Channel Blockers; Potassium Channels - metabolism; Vascular Patency - drug effects; Vertebrates: cardiovascular system
• ISSN: 0009-7330; 1524-4571
• DOI: 10.1161/hh0202.103713

Experimental data suggest that vascular ATP-sensitive potassium (KATP) channels regulate coronary blood flow (CBF), but their role in regulating human CBF is unclear. We sought to determine the contribution of KATP channels to resting conduit vessel and microvascular function in the human coronary circulation. Twenty-five patients (19 male/6 female, aged 56±12 years) were recruited. Systemic and coronary hemodynamics were assessed in 20 patients before and after KATP channel inhibition with graded intracoronary glibenclamide infusions (4, 16, and 40 μg/min), in an angiographically smooth or mildly stenosed coronary artery following successful elective percutaneous coronary intervention to another vessel. Coronary blood velocity was measured with a Doppler guidewire and CBF calculated. Adenosine-induced hyperemia was determined following bolus intracoronary adenosine injection (24 μg). Time control studies were undertaken in 5 patients. Compared with vehicle infusion (0.9% saline), glibenclamide reduced resting conduit vessel diameter from 2.5±0.1 to 2.3±0.1 mm (P