Effects of bisoprolol combined with Dahuang on circadian rhythm of blood pressure,NO and ET in experimental rats

doi:10.3969/j.issn.1002-7386.2017.18.003

Abstract：Objective To observe the effects of bisoprolol combined with Dahuang on circadian rhythm of blood pressure(BP),nitric oxide (NO)and endothelin (ET)in experimental rats. Methods Ninety-six healthy male SD rats weighted 250 ~ 300 grams were randomly divided into three groups,with 32 rats in each group,then every group was redivided into 4 subgroups randomly,with 8 rats in each group. The rats in control group (groupⅠ)were given placebo,and the rats in groupⅡwere given bisoprolol (3mg·kg -1 ·d -1 )by gavage,and the rats in group Ⅲ were given bisoprolol (300mg·kg -1 ·d -1 )by gavage. On one day before drug administration,the systolic pressure of rats was measured by rat-tail manometry in 4 different time points (02: 00,08 : 00,14 : 00,20 : 00). After 4 weeks,the systolic pressure of rats was measured again by rat-tail manometry in the 4 different time points. Then the rats were sacrificed and myocardial tissues were obtained. The levels of ET-1,NO in myocardial tissues were detected by radioimmunity method and acid reductase method. Results As compared with that in group Ⅰ,the systolic blood pressure in group Ⅱ and group Ⅲ was decreased,and the levels of ET-1 in myocardial tissues were decreased,however,the levels of NO were significantly increased (P < 0. 05). Moreover the decrease degree in group Ⅲ was more obvious than that in group Ⅱ (P < 0. 05). The levels of ET-1 in group Ⅲ were significantly lower than those in group Ⅱ(P < 0. 05),and the levels of NO in myocardial tissues in group Ⅲ were obviously higher than those in group Ⅱ (P < 0. 05). After treatment,the systolic blood pressure,amplitude,peak phase and peak time of curve of ET-1 and NO in myocardial tissues in group Ⅱ and group Ⅲ had different extent displacement (P < 0. 05). Conclusion The bisoprolol combined with Dahuang has synergetic effects,which can obviously decrease blood pressure,at the same time, which has obvious effects on circadian rhythm of blood pressure and endothelial system function of rats.