Abstract
Background Although cigarette smoking is thought to constrict peripheral vessels, details have not been clarified because of the limitation of spatial resolution in conventional X-ray angiography systems. Synchrotron radiation microangiography can identify small arteries down to 50 μm in diameter. Method and Results Male Wistar rats (n=9) were made to smoke a cigarette using the modified Griffith snout exposure system. Angiography of the rat hind limb was performed before, during, and 15 min after smoking. Arteries were classified into 3 groups based on the pre-smoking diameter: Group S: <100 μm, Group M 100-200 μm, Group L: >200 μm). In Groups M and L, arteries were constricted with smoking (mean diameter 140-106 μm; p<0.001, 260-162 μm; p<0.00001, respectively), whereas no constriction was noted in Group S (82-83 μm). Constricted arteries in Groups M and L returned to pre-smoking levels at 15 min after cessation of smoking. Conclusion The acute changes brought about by cigarette smoking in rat peripheral arteries could be identified by synchrotron radiation microangiography. Cigarette smoking exclusively constricted arteries greater than 100 μm in diameter, which means there is vessel-size dependency of the impairment. (Circ J 2007; 71: 418 - 422)
