Cardiovascular pharmacology of 3-n -butylphthalide in spontaneously hypertensive rats

✍ Scribed by D. Tsi; B. K. H. Tan

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 144 KB
• Volume: 11
• Category: Article
• ISSN: 0951-418X
• DOI: 10.1002/(sici)1099-1573(199712)11:8<576::aid-ptr174>3.0.co;2-7

✦ Synopsis

The hypotensive and vasorelaxant effects of 3-n-butylphthalide (BuPh) and its possible mechanisms of action were investigated in spontaneously hypertensive rats (SHR) for the first time. A 13-day intraperitoneal infusion of BuPh at doses of 2.0 and 4.0 mg/day produced a transient hypotensive effect while a dose of 0.5 mg/day showed a significant hypotensive effect only on day 12. BuPh at 0.5 mg/day had no effect on the plasma and tissue angiotensin converting enzyme (ACE) activities, or on the tissue lipid peroxidation index. BuPh relaxed endothelium-intact and denuded aortic rings precontracted with phenylephrine and KCl. N G -nitro-L-arginine methyl ester, an inhibitor of nitric oxide synthase, did not attenuate the vasorelaxant activity of BuPh. The cumulative concentration response curves of phenylephrine and Ca 2+ (in CaCl 2 -free, high KCl medium) were non-competitively inhibited by BuPh. However, BuPh did not interfere with the caffeine-induced release of intracellular Ca 2+ . It appears that the vasorelaxant effect of BuPh could be attributed to the blockade of Ca 2+ entry, possibly through voltage-and receptor-operated Ca 2+ channels, thereby lowering the systolic blood pressure of SHR.