Right ventricular myocardial oxygen tension is reduced in monocrotaline-induced pulmonary hypertension in the rat and restored by myo-inositol trispyrophosphate

Figures

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  Figure 1. Histological and hemodynamic characterization of rats with monocrotaline-induced pulmonary hypertension and control rats. Representative hematoxylin and eosin stained images from control (A) and monocrotaline (MCT)-treated (B) rats, demonstrating small pulmonary arterioles (arrows). Yellow bars indicate arteriolar wall thickness. Clear wall thickening and luminal stenosis can be seen in a MCT rat. (C) demonstrates pulmonary vascular resistance (PVR), (D) mean pulmonary artery pressure (mPAP), and (E) left and right ventricular end-diastolic volumes. Representative right ventricular pressure–volume loops and tracings of right ventricular pressure and volumes are presented for control (F) and MCT (G) rats. (H) presents representative RV and LV PV loops from control and MCT rats. Horizontal lines represent mean (red) and median (black), the bottom and the top of the boxes represent the upper and the lower quartile, he whiskers represent 10th and 90th percentile, while the solid circles represent the individual data points. (C–E) control n = 9; MCT n = 14; since the data exhibited non-normal distribution, the groups were compared using Mann–Whitney test; * p < 0.05.

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  Figure 2. Echocardiographic characterization of rats with monocrotaline-induced pulmonary hypertension and normal rats. Short-axis view of the rat heart in control (A) and monocrotaline-treated (B) rats. Yellow line outlines contours of the right ventricular cavity, white line of the left ventricular cavity. Markedly dilated right ventricle and compressed left ventricle can be seen in monocrotaline-treated rats (B). Lower panels demonstrate right diastolic wall thickness (C) and ventricular fractional shortening (D). Horizontal lines represent mean (red) and median (black), the bottom and the top of the boxes represent the upper and the lower quartile, he whiskers represent 10th and 90th percentile, while the solid circles represent the individual data points. Control n = 12; MCT n = 12; since the data exhibited non-normal distribution, the groups were compared using Mann–Whitney test;* p < 0.05.

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  Figure 3. Measurements of myocardial oxygen tension. (A) An image demonstrating measurement of right ventricular (RV) partial oxygen pressure (pO2) using a fiber-optic probe inserted into the RV, almost parallel to the epicardial surface. Representative recordings of pO2 measurements in control and monocrotaline-treated rats are presented on panels (B) and (C), respectively. The horizontal axis indicates pO2. Panel B presents pO2 values measured under 40% fraction of inspired oxygen (NORMAL O2), while panel C presents pO2 values measured under 40% fraction of inspired oxygen (NORMAL O2) and 100% fraction of inspired oxygen (HIGH O2). RV, right ventricle; LV, left ventricle. The results are summarized for the right and left ventricle on panels (D) and (E), respectively. Correlations between RV and LV pO2 and wall stress as well as LV systolic pressure are shown on panels (F) through (I). Horizontal lines represent mean (red) and median (black), the bottom and the top of the boxes represent the upper and the lower quartile, he whiskers represent 10th and 90th percentile, while the solid circles represent the individual data points. Control n = 11; MCT = 13. Kruskal–Wallis ANOVA was used to…