Protective effects of nifedipine on endothelial cells in spontaneously hypertensive rats

Yuanying ZHANG; Linlin GAO; Furong LI

ABSTRACT

BACKGROUND:

Research has proved that nifedipine can improve the functions of vascular endothelial cells. However, it still needs further study on its mechanism on dilating vessels.

OBJECTIVE:

To observe the effects of controlled-release nifedipine to nitrogen monoxide(NO) and induced nitric oxide synthase(iNOS) in spontaneously hypertensive rats(SHR).

DESIGN:

Comparative observational study based on experimental animals.

SETTING:

Experimental animal centre in a medical college.MATERIALS This study was completed in Experimental Animal Centre of Shandong University during April to May 2002. Twenty-one recombinant inbred rats of clean class with body mass of(300 ± 2) grams were provided by Experimental Animal Centre of Shandong University. They were randomly divided into three groups control group, normal group and low dose group,each with 7 rats.

METHODS:

Saline(10 mL/kg), 10 mL/kg and 3 mL/kg controlled-release nifedipine solution(0. 3 g/L) were poured into stomach to rats in control group, normal dose group and low dose group once everyday for 15 days respectively. Eyeball was removed to collect blood and heart and lung were removed at the same time to test the content of NO and iNOS in serum after last administration.MAIN OUTCOME

MEASURES:

Content of NO, comparison of iNOS activity between groups.

RESULTS:

There was significant difference on NO content between normal dose group and control group, low dose group after 15 days' administration ( P < 0. 01 ) . Compared with control group and low dose group, there was significant difference on the iNOS activity in heart and lung of normal dose group(P <0.01, P <0.05).

CONCLUSION:

While nifedipine reduces the blood pressure, it can also improve the content of NO and resist the increasing activity of iNOS casued by increased blood pressure.