1D1518 The effects of temocapril and hydralazine on HbNO dynamics in chronic NG-nitro-L-arginine- methylester (L-NAME) treated rats

• Published in: Journal of Pharmacological Sciences 2003, Vol.91 (suppl.1), p.77-77
• Main Authors: Kazuyoshi Kirima, Koichiro Tsuchiya, Shinji Abe, Toyoshi Hasegawa, Moe Kyaw, Michiyo Shikishima, Yuki Motobayashi, Masanori Yoshizumi, Toshiaki Tamaki
• Format: Article
• Language: Japanese
• ISSN: 1347-8613

Nitric oxide (NO) plays numerous physiological roles. As it is reported that the abnormality of blood NO is associated with many diseases, to evaluate NO dynamics is very important. Recently we established a new quantitation method of blood NO in terms of HbNO by electron paramagnetic resonance (EPR) method. Using this method, we examined the effects of temocapril (T) and hydralazine (H) on NO dynamics in L-NAME treated rats. From Day 0 to 13, rats were received distilled water (group 1), or L-NAME (1 g/L：groups 2 - 5). Vehicle (group 1, 2), T (group 3：2 mg/kg/day, group 4：20 mg/kg/day) and H (group 5：0.5 g/L) were administered from Day 7 to 15. On Day 16, venous blood was obtained and measured by EPR method. In group 1, blood pressure did not alter throughout the experiment and signal intensity of HbNO was 31.85 ± 6.38 (A. U. ). L-NAME induced hypertension (groups 2) and reduced the blood HbNO (13.81 ± 2.03 AU. ). T (high dose) and H showed same degree of hypotensive effect. T restored the reduced blood HbNO in a dose-dependent manner (2 mg/kg/day; 17.96 ± 1.68 A. U. , 20 mg/kg/day; 22.08 ± 2.58 A. U. ). On the other hand, H didn't improve the abnormality of HbNO (12.45 ± 2.22 A. U. ). In this study, we directly confirmed that ACE inhibitor improved the abnormality of NO dynamics in L-NAME treated rats.