高石, 和美 Department of Dental Anesthesiology, Institute of Health Biosciences, the University of Tokushima Graduate School 徳島大学 教育研究者総覧 KAKEN研究者をさがす
キノシタ, ヒロユキ Department of Anesthesiology, Aichi Medical University
ハタケヤマ, ノボル Department of Anesthesiology, Aichi Medical University
アズマ, トシハル Department of Anesthesiology & Pain Medicine, Kohnodai Hospital, National Center for Global Health and Medicine
中屋, 豊 Division of Cardiology, Shikoku Central Hospital of the Mutual Aid Association of Public School Teachers 徳島大学 教育研究者総覧 KAKEN研究者をさがす
Background : Propofol causes vasodilation via endothelium-dependent and -independent mechanisms. Because endothelial function is impaired with aging, the effects of propofol on endothelium-dependent vasodilation might be altered by aging. The aim of this study was thus to determine the effects of aging on vascular responses to propofol. Methods : Young (4-6 weeks old) or adult (16-25 weeks old) rats were anesthetized with sevoflurane. The thoracic aorta was dissected and cut into pieces 3-4mm in length. In some rings, the endothelium was deliberately removed. The ring segment of the aorta was mounted for isometric force recording at a resting tension of 0.5-1.0 g in a 2 ml organ bath, containing Krebs-Ringer bicarbonate buffer. Arteries were precontracted with phenylephrine, and the function of endothelium was confirmed with acetylcholine. Then, we studied the concentration-dependent effects of propofol in endothelium-intact (control group) and -denuded aortic rings (denuded group), as well as those treated with N[ω]-nitro-L-arginine methylester (L-NAME group). Results : Relaxation due to propofol was observed in the control groups of both young and adult rats in a concentration-dependent manner, but the magnitude of relaxation was significantly greater in young rats. In addition, in young rats, relaxation due to propofol was significantly and equally reduced in both L-NAME and denuded groups at all propofol concentrations that we studied (10[-6]-10[-3] M). In adult rats, relaxation due to propofol was quite similar between control and L-NAME groups at all propofol concentrations, whereas it was significantly reduced in the denuded group. Conclusion : These results suggest that endothelium-derived nitric oxide plays an important role in propofol-induced vasodilation in young rats, but not in adult rats.
The journal of medical investigation : JMI
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