Objective To investigate the effect of different light regimen on blood pressure in rats(SD). Methods 64 male and female SD rats were randomly divided into 3 groups, the constant light group ( LL, male:n = 11; female: n = 11) , constant dark group ( DD, male: n = 11; female: n = 11) , light - dark cycle 12 : 12 group( LD,male:n =9; female;n = 10) , respectively. Blood pressure was measured every ten days during the experiment. After 40 days, the mice were sacrificed and dissected out heart and kidney to calculate relative ratio with weight of the rats. Results The blood pressure of LL and DD were significantly higher than that of the LD group at day 10,day 20 and day 30 respectively( P <0.05). A down trend of blood pressure was found in LL and DD rats at day 40 and there was no difference with the LD group ( P > 0. 05 ) . During the experiments, the body weights of the rats increased The weight of male rats were significantly different among groups ( P < 0. 05 ) . The body weight of male rats in LL group was significantly higher than that of the DD and LD groups at day 10(P<0.05) . For female rats, the speed of the average - increased - body - weight was significantly higher in LL and DD group compared with that in LD at day 10(P<0. 05). The body weight ratio of heart and kinney were significantly higher in LL and DD compared with LD group ( P < 0. 05 ) . Conclusion Abnormal light regimen causes the instability of the blood pressure and body weight or the abnormal elevation of blood pressure in rats. The abnormal light regimen might be a risk factor of hypertension in rats.%目的 探讨不同光照制对大鼠体重、血压、心率等的影响.方法 SD大鼠随机分为持续光照组、持续黑暗组及正常光照组,定期监测大鼠动脉血压、心率和体重变化,40d后处死,取心脏和肾脏计算相对重量.结果 在实验第10、20和30天,光照组和黑暗组大鼠动脉血压均明显高于正常组大鼠(P＜0.05);光照组及黑暗组第40天血压下降,与正常组比较差异无统计学意义(P＞0.05).实验期间不同处理组间大鼠心率变化差异无统计学意义(P＞0.05).实验期间雄性大鼠各组间体重变化差异有统计学意义(P＜0.05);实验第1~10天光照组雄性大鼠平均体重增长速度明显高于黑暗组和正常组(P＜0.05);雌性大鼠光照组及黑暗组第1~10天的平均体重增长速度明显高于正常组(P＜0.05).实验第40天后,光照组和黑暗组大鼠心脏和左侧肾脏与体重比值明显高于正常组(P＜0.05).结论 异常光照制导致大鼠血压和体重不稳定或异常升高,引起大鼠心脏及肾脏重量异常改变或增加,异常光照制可能是影响高血压发生发展的风险因素.
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