Christensen K L, Mulvany M J, Jespersen L T
Institute of Pharmacology, University of Aarhus, Denmark.
J Hypertens. 1990 Apr;8(4):321-6. doi: 10.1097/00004872-199004000-00005.
We investigated the reliability of calculating the mean blood pressure (MBP) in spontaneously hypertensive rats (SHR) from the systolic and diastolic blood pressures (SBP; DBP), using a form factor, calculated as: (MBP - DBP)/(SBP - DBP). The mean values of this form factor, as determined by blood pressure curve integration, were 0.459 and 0.450 in awake and anaesthetized SHR, respectively. There was no change in the form factor with pulse frequency. When direct femoral artery MBP measurements (x) were compared with MBP values (y) calculated from tail-cuff measurements of SBP and DBP using the form factor, the linear relationship between the two parameters was: y = 0.91x + 1.5 mmHg (r = 0.98). Actually, direct measurements confirmed that the tail artery MBP was 6-7% lower than the femoral artery MBP. In awake Wistar-Kyoto (WKY) rats, the form factor was 0.468. We therefore concluded that an approximate form factor value of 0.46 could be used in rats to estimate the MBP from known values of SBP and DBP. We further suggest that, because pulse pressure in any given rat remains relatively constant with time, SBP and DBP can be estimated in experiments by initially measuring the pulse pressure; thus, only the MBP need be recorded thereafter.
我们研究了在自发性高血压大鼠（SHR）中，通过收缩压和舒张压（SBP；DBP）计算平均血压（MBP）的可靠性，使用一个形状因子，计算方式为：(MBP - DBP)/(SBP - DBP)。通过血压曲线积分确定的该形状因子的平均值，在清醒和麻醉的SHR中分别为0.459和0.450。形状因子不随脉搏频率变化。当将直接股动脉MBP测量值（x）与使用该形状因子从尾套测量的SBP和DBP计算得到的MBP值（y）进行比较时，这两个参数之间的线性关系为：y = 0.91x + 1.5 mmHg（r = 0.98）。实际上，直接测量证实尾动脉MBP比股动脉MBP低6 - 7%。在清醒的Wistar - Kyoto（WKY）大鼠中，形状因子为0.468。因此，我们得出结论，在大鼠中可以使用近似形状因子值0.46，根据已知的SBP和DBP值来估计MBP。我们进一步建议，由于任何给定大鼠的脉压随时间保持相对恒定，在实验中可以通过最初测量脉压来估计SBP和DBP；因此，此后只需记录MBP即可。
