Page 142 - Assessing right ventricular function and the pulmonary circulation in pulmonary hypertension Onno Anthonius Spruijt
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proportion of remodelled vessels with double elastic lamina (Figure 4A), Ki67 score (Figure 4B), and right ventricular hypertrophy (RV/LV+sep ratio, DCA: 0.48±.03 imatinib: 0.32±.02; P<0.001 in comparison to placebo group: 0.61±.02, Figure 4C), consistent with previous data. This was accompanied by a marked reduction in the phosphorylation of 18FLT k3 (Figure 4D). This was further supported by the direct measurement of lung tissue 18FLT (Figure 4E).
A.
B.
0.15
0.10 0.05 0.00
Lung 18FLT uptake (phosphoryla on rate k3)
C.
0.5 0.4 0.3 0.2 0.1 0.0
Lung 18FLT uptake (Tissue count)
D.
Ki67 50μm
E. Lung 18FLT uptake (k3)
F.
C
** *
1W_MCT
4W_MCT
C
* *
1W_MCT
4W_MCT
and prolifera on (Ki‐67)
15 10 5
0
0.00 0.05 0.10 0.15
Phosphorylation rate (k3)
Figure 3. A. Representative static images from dynamically acquired positron emission tomography images over 60 minutes after 18FLT injection. B. Compartmental analysis demonstrating a significantly increased lung 18FLT uptake (phosphorylation rate k3) in rats after 1 week (1W) and 4 weeks (4W) of monocrotaline (MCT) injection. C. Measurement of 18FLT uptake by gamma counter confirms significantly increased 18FLT uptake in MCT rats. %ID/gm indicates percentage of injected dose per gram of tissue. Data are expressed as mean±SEM; n≥5 in each group. **P<0.01 , *P<0.05 vs control (C) group. D. Immunostaining with Ki67 in MCT lung sections demonstrated increased expression of Ki‐67 positive nuclei around remodelled vessels. E. Relationship between 18FLT phosphorylation rate and proliferation index Ki‐67 score (r2=0.77, P<0.0001) in MCT rat lung. F. Prominent TK1 and ENT1 expression was observed around the remodelled peripheral pulmonary vessels.
Western blot analysis of lung homogenates demonstrated a significant increase in ENT1 and TK1 expression in the 4 week MCT rat lung, which was attenuated by imatinib and DCA treatments (Figure 4F).
MCT Control MCT
Control
Ki-67 Score
min-1
%ID/gm
