Figure 2
Mean blood pressure (mBP, 2a); Changes in individual mean blood pressure (delta mBP, 2b).; Heart rate (HR, 2c); Changes in individual heart rate (delta HR, 2d); and Changes in time domain and frequency domain measures of heart rate variability (HRV, 2e) in sham (control) or Augsburg particulate matter (PM 2.5 -AB, exposed) instilled SHRs. The vertical bars exhibit arithmetic mean values (mean ± SE) of sham (white; n = 5) and exposed (black; n = 5) groups. The summary statistics for the analysis of repeated measurements revealed that delta mBP differences between groups were significant on day 2 and 4 post exposure (p < 0.04). Delta mBP declined and reached almost baseline values on day 5.. Absolute HR values responded with a lag of 1 day to PM2.5-AB exposure and were significantly lower in the exposure group by 6% (325.1 ± 8.8 bpm vs 348.9 ± 12.5 bpm, p < 0.03) on the 3rd day after instillation. The summary statistics for the analysis of repeated measurements revealed that neither the area under the curve nor differences in HR values reached the level of statistical significance. In Figure 2e each bar represents a combined mean value of: 12 5-minutes segments/12-h dark period/rat) from 5 rats. SDNN: standard deviation of normal to normal (NN) intervals. RMSSD: square root of the mean of squared differences between adjacent NN intervals. LF/HF: ratio of the absolute powers in the low-frequency (LF: 0.20 Hz to 0.75 Hz) and high-frequency bands HF: 0.75 Hz to 2.5 Hz). * indicates significant difference of (p < 0.04: BP; p < 0.03: HR) between exposed (black) and sham (white) SHRs.