Age-related decrease in vqsodilation and anti-aggregating function of vascular endothelium
Grant-in-Aid for General Scientific Research (C)
|Allocation Type||Single-year Grants |
|Research Institution||University of Tokushima |
MORITOKI Hideki Faculty of Pharmaceutical Sciences, University of Tokushima,, 薬学部, 助教授 (10035545)
HORIO Shuhei Faculty of Pharmaceutical Sciences, University of Tokushima,, 薬学部, 助手 (80145010)
FUKUZAWA Kenji Faculty of Pharmaceutical Sciences, University of Tokushima,, 薬学部, 助教授 (90035551)
|Project Period (FY)
1985 – 1987
Completed (Fiscal Year 1987)
|Budget Amount *help
¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1987: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 1986: ¥400,000 (Direct Cost: ¥400,000)
|Keywords||Aging / Vasodilation / Endothelium / cGMP / サイクリックGMP / 内腔潅流液 / 抗血小板活性 / 血管拡張反応減弱 / 血管内膜 / 血小板凝集阻止能 / 血管拡張剤 / フリーラジカル / アデノシン / ヒスタミン|
1. Effects of aging on the dilation caused by vasodilators and the formation of cGMO, and anti-aggregation activity of endothelium of vessels were studied on rat thoracic aorta.
2. Endothelium-dependent vasodilation progressively decreased with increase in age of rats, and in preparations from rats of over 60 weeks old, the dilator response was no longer detectable.
3. Histamine, acetylcholine, adenosine or nitrovasodilators induced cGMP accumulation in aorta from rats of 8 weeks old, with no change in cAMP level. This increase in cGMP level also decreased with aging.
4. Removal of the endothelium completely abolished the dilation and the cGMP accumulation.
5. These results suggest that aging reduces the ability of the endothelium to produce endothelium derived relaxing factor (EDRF), which stimulates quanylate cyclase. and so decreawes cGMP accumulation.
6. Thus the decreased dilator response of the aorta to vasodilators during aging is probably due to both gradual loss of endothelium func
tion and reduction of guqnylate cyclase activity.
7. Next, we examined whether the ability of endothelium to prevent platelet aggregation also decreased with aging. Lumen of the vessels was perfused with Krebs solution containing acetylcholine. Plasma rich platelet was first incubated wiht the perfusate, and then ADP was added to induce aggregation.
8. The perfusate of the artery from young rats effectively inhibited ADP-induced aggregation.
9. With increase in age of rats to 100 weeks, the anti-aggregating activity of the perfusate significantly decreased.
10. Endothelium denudation caused complete loss of the anti-aggregating activity. This indicates that a substance which prevents aggregation, originates from the endothelium.
11. The cyclooxygenase inhibitor indomethacin also abolished anti-aggregating activity, indicating mediation of PGs.
12. Thus, these results suggest that endothelium produces some anti-aggregating substance, probably PGI_2, in response to vasodilators and this production is reduced by aging. Less
Report (2 results)
Research Products (12 results)