应用植入式遥测技术观察自发性高血压大鼠血压的昼夜波动

目的应用植入式遥测技术观察自发性高血压大鼠在清醒无束缚状态下血压昼夜波动变化。方法取8只SPF级3月龄雄性SHR大鼠,进行C50-PXT植入子植入手术,恢复7 d后,用遥测系统进行24 h连续清醒无束缚的血压监测,并用EMKA分析软件对动态血压心率均值、24 h血压心率趋势等指标进行分析。结果 3月龄的SHR大鼠血压和心律呈昼夜节律性变化,白昼阶段血压明显低于夜间阶段(P<0.01),血压在1∶30～2∶30和20∶30～21∶30时出现两个高峰期,14∶00～14∶30时出现一低谷期。其中夜间阶段平均收缩压为166.02 mmHg,两个收缩压峰值分别为172.13 mmHg和171.38 mmHg;白昼平均收缩压是162.73 mmHg,收缩压谷底值为155.73mmHg。而心率两个高峰期出现在1∶30～2∶00和20∶00～21∶00,高峰值分别为375.00次/分和373.26次/分;心率低谷出现在11∶00左右,谷底值为310.91次/分,白昼和夜间的平均心率分别为328.85次/分和346.05次/分。结论 3月龄的SHR大鼠血压和心律呈昼夜节律性变化,血压和心率在夜间出现两个高峰,白昼出现一个低谷,且夜间的平均血压和心率要高于白昼,SHR大鼠的血压和心率的节律变化与其活动有关。植入式遥测技术可准确反映SHR大鼠血压昼夜的节律性变化,有助于正确评价抗高血压药物的作用和高血压的生理机制研究。

Measurement of circadian spontaneously hypertensive rhythm of blood pressure in rats by implantable telemetry

Objective To observe the circadian fluctuation of blood pressure in unrestrained spontaneously hyper- tensive rats （SHR） by implantable telemetry. Methods Eight 3-month-old SPF SHR rats were implanted with a C50- PXT telemetry device intraperitoneally. Seven days later, the blood pressure was continuously monitored in conscious and unrestrained state for 24 h by the telemetry system, and the dynamic changes of mean values of blood pressure and heart rate and their 24-hour trend diagrams were analyzed using EMKA software. Results The blood pressure and heart rate in the rats showed circadian rhythm changes. It was significantly lower during the daytime than that at the nighttime （ P 〈 O. 01 ）. The blood pressure showed two peak periods at 1 ： 30 a. m. - 2：30 a.m. and 8：30 p.m. - 9：30 p. m. , and a val- ley period at 2：00 p. m. -2：30 p.m. The mean systolic blood pressure was 166.02 mmHg at the nighttime, and the two peak systolic blood pressures were 172.13 mmHg and 171.38 mmHg, respectively. The mean SBP was 162.73 mmHg dur- ing the daytime, and the valley bottom of SBP was 155.73 mmHg. But the heart rate showed two peak periods at 1：30 a. m. - 2：O0 a.m. and 8：00 p.m. - 9：00 p. m. , with a peak value of 375.00 time/min and 373.26 time/rain, respective- ly. The valley bottom value of heart rate （310. 91 time/rain） was around 11 a.m. or so. The mean heart rate was 328.85 time/rain during the daytime and 346.05 time/min at the nighttime. Conclusions Three-month old spontaneously hyper-tensive rats show circadian rhythm changes of blood pressure and heart rate, with two peaks at the nighttime and a valley during the daytime. The mean blood pressure and heart rate are lower during the daytime than that in the night. The circa- dian rhythm of blood pressure and heart rate in the SHR rats is related with their activilies. Implantable telemetry can accu- rately reflect the circadian rhythmicity of blood pressure in SHR rats, and properly contribute to the evaluation of antihyper- tensive drugs and research of physiological mechanism of hypertensicn.