Phenotypic assessment of pulmonary hypertension using high-resolution echocardiography is feasible in neonatal mice with experimental bronchopulmonary dysplasia and pulmonary hypertension: a step toward preventing chronic obstructive pulmonary disease

Figures & data

Figure 1 Hyperoxia exposure decreases body weight in neonatal mice.

Notes: Body weight of neonatal mice exposed to air or hyperoxia for 14 days. Values are mean ± SD from seven individual animals in each group from one experiment. Significant differences between air and hyperoxia groups are indicated by *P<0.05.
Abbreviation: SD, standard deviation.

Figure 2 Hyperoxia exposure increases lung MDA protein levels.

Notes: Lung protein obtained from neonatal mice exposed to air or hyperoxia for 14 days was subjected to immunoblotting using anti-MDA or -β-actin antibodies. Representative immunoblot showing differential MDA protein adduct expression in the region between 40 and 80 kDa (A). Densitometric analysis wherein the aforementioned MDA protein adduct band intensities were quantified and normalized to β-actin (B). Values are mean ± SD from four individual animals in each group from one experiment. Significant differences between air and hyperoxia groups are indicated by *P<0.05.

Abbreviations: MDA, malondialdehyde; SD, standard deviation.

Figure 3 Hyperoxia exposure increases lung iNOS protein levels.

Notes: Lung protein obtained from neonatal mice exposed to air or hyperoxia for up to 14 days was subjected to immunoblotting using anti-iNOS or -β-actin antibodies. Representative immunoblot showing iNOS protein expression (A). Densitometric analyses wherein the iNOS band intensities were quantified and normalized to β-actin (B). Values are mean ± SD from three individual animals in each group from one experiment. Significant differences between air and hyperoxia groups are indicated by *P<0.05.
Abbreviations: iNOS, inducible nitric oxide synthase; SD, standard deviation.

Figure 4 Hyperoxia exposure induces alveolar simplification.

Notes: Representative hematoxylin and eosin–stained lung sections obtained at 14 days of age from neonatal mice exposed to air (A) or hyperoxia (B). Alveolarization was quantified by RAC (C) and MLIs (D). Values are mean ± SD from three individual animals in each group from one experiment. Significant differences between air and hyperoxia groups are indicated by *P<0.05. Scale bar =100 µM.
Abbreviations: WT, wild type; RAC, radial alveolar count; MLI, mean linear intercept; SD, standard deviation.

Figure 5 Hyperoxia exposure decreases pulmonary vascular density.

Notes: Representative vWF-stained lung blood vessels obtained at 14 days of age from neonatal mice exposed to air (A) or hyperoxia (B). Quantitative analysis of vWF-stained lung blood vessels per high power field (C). Values are mean ± SD from three individual animals in each group from one experiment. Significant differences between air and hyperoxia groups are indicated by *P<0.05. Scale bar =100 µM.
Abbreviations: WT, wild type; vWF, von Willebrand factor; SD, standard deviation.

Figure 6 Hyperoxia exposure induces pulmonary vascular remodeling.

Notes: Representative α-SMA-stained resistance pulmonary arteries obtained at 14 days of age from neonatal mice exposed to air (A) or hyperoxia (B). Quantitative analysis of pulmonary vascular remodeling by medial thickness index (C). Representative immunoblot showing α-SMA protein expression (D). Densitometric analyses wherein the α-SMA band intensities were quantified and normalized to β-actin (E). Values are mean ± SD from three individual animals in each group from one experiment. Significant differences between air and hyperoxia groups are indicated by *P<0.05. Scale bar =100 µM.
Abbreviations: WT, wild type; α-SMA, alpha smooth muscle actin; SD, standard deviation.

Figure 7 Hyperoxia exposure induces PH.

Notes: Representative PWD Echo recording of PA blood flow obtained at 14 days of age from neonatal mice exposed to air (A) or hyperoxia (B). PAT (C) and PAT/ET ratio (D) were estimated from the PWD Echo recordings of the PA blood flow. Values are mean ± SD from four individual animals in each group from one experiment. Significant differences between air and hyperoxia groups are indicated by *P<0.05.

Abbreviations: PWD, pulsed-wave Doppler; Echo, echocardiography; PA, pulmonary artery; PAT, pulmonary acceleration time; ET, ejection time; SD, standard deviation; PH, pulmonary hypertension.

Figure 8 Hyperoxia exposure induces RVH.

Notes: Representative M-mode Echo recording obtained at 14 days of age from neonatal mice exposed to air (A) or hyperoxia (B). RVFW thickness in end-diastole (C) was estimated from the M-mode Echo recordings. Values are mean ± SD from four individual animals in each group from one experiment. Significant differences between air and hyperoxia groups are indicated by *P<0.05.
Abbreviations: RVH, right ventricular hypertrophy; RVFW, right ventricular free wall; Echo, echocardiography; SD, standard deviation.