Figure 1.
Effects of PPAR agonists on vascular tissue.
The vaso-relaxant responses of three different PPAR agonists in (A) pulmonary artery, (B) aorta and (C) mesenteric artery. GW501516 or GW0742, which activate PPARβ/δ, rosiglitazone, which activates PPARγ or bezafibrate, which activates PPARα, were added to U46619 [EC80] contracted arteries in increasing concentrations. Responses of vehicle (DMSO; final accumulated maximum of 0.6%) are shown as ‘vehicle control’. The data is the mean ± standard error of the mean for n = 4−8 experiments. Drug induced responses were compared with time control using two-way ANOVA and a p value of <0.05 was assumed statistically significant and denoted by*. Where p>0.05, the lack of statistical significance is denoted by ns.
Figure 2.
Characterisation of relaxant effects of GW0742 in pulmonary vessels.
L-NAME (1 mM) had no effect on relaxant responses induced by GW0742 in U46619 contracted mouse pulmonary artery (A). GW0742 induced similar relaxant responses in mouse pulmonary artery contracted with EC80 concentrations of U46619 or phenylephrine (PE) (B). GW0742 induced relaxant responses in rat 3rd/4th order pulmonary artery contracted with 100 nM U46619 (C) or with hypoxia (D), vehicle control for these experiments was again DMSO at accumulated maximum concentrations of 0.8 and 0.4% v/v respectively. Data is the mean ± standard error of the mean for n = 4−8. Drug induced responses were compared with time control using two-way ANOVA and a p value of <0.05 was assumed statistically significant and denoted by*. Where p>0.05, the lack of statistical significance is denoted by ns.
Figure 3.
Role of IP receptors in the responses of PPARβ/δ agonists in blood vessels.
Relaxations induced by the PPAR β/δ agonist GW0742 in (A) mesenteric artery and (B) pulmonary artery from wild type mice were compared to responses in tissues from IP−/− mice. Vessels were pre-contracted with EC80 concentrations of U46618. The data is the mean ± standard error of the mean for n = 4−5 experiments. Drug induced responses were compared using two-way ANOVA and a p value of <0.05 was assumed statistically significant and denoted by*. Where p>0.05, the lack of statistical significance is denoted by ns.
Figure 4.
Role of PPAR β/δ receptors in the effects of GW0742 in blood vessels.
Relaxations induced by the PPAR β/δ agonist GW0742 in (A) pulmonary artery, (B) mesenteric artery and (C) aorta from wild type mice were compared to tissue from PPAR β/δ−/− mice. Vessels were pre-contracted with EC80 concentrations of U46619. The data is the mean ± standard error of the mean for n = 4 experiments. Drug induced responses were compared using two-way ANOVA and a p value of <0.05 was assumed statistically significant and denoted by*. Where p>0.05, the lack of statistical significance is denoted by ns.
Figure 5.
Effect of GW0742 on cGMP and cAMP levels in aortic rings.
Effects of 30 µM GW0742 (GW), 10 µM sodium nitroprusside (SNP; an activator of soluble guanylate cyclase) and 10 µM forskolin (FORSKO; an activator of adenylate cyclase) on (A) cGMP and (B) cAMP levels in mouse aortic rings. The data is the mean ± standard error of the mean for n experiments. cGMP: vehicle control (DMSO; 0.03%) and GW0742, n = 14; SNP, n = 9; forskolin, n = 4. cAMP: DMSO and GW0742, n = 11; SNP, n = 6; forskolin, n = 7. Drug induced responses were compared using one-way ANOVA followed by Dunnett's Multiple Comparison Test. Statistical significance was assumed where p<0.05 and is denoted by *.
Figure 6.
Effects of GW0742 on activation of Rho A in aortic rings.
Mouse aortic rings were treated with or without U46619 (10 nM) before the additions of GW0742 and Y27632 (10 µM) or vehicle control (DMSO; 0.03%) and the content of GTP bound RhoA was measured in tissue extracts by ELISA. Data is the mean ± standard error of the mean for n = 4 experiments. Data was analysed using one sample T-test for normalized data or by one-way ANOVA followed by Bonferroni's Multiple Comparison Test. Significance was defined by **p<0.01 versus control and ##, ### p<0.01 and p<0.001 treatments with U46610 compared to respective control.
Figure 7.
Effects of GW0742 on membrane potential in mesenteric arteries.
Membrane potential in mesenteric arteries was measured under control conditions (resting membrane potential; r.m.p.) before GW0742 was added in a cumulative manner. Data is the mean ± standard error of the mean for n = 4. Data was analysed using one-way ANOVA followed by Dunnett's Multiple Comparison Test. Significance was assumed and defined by *p<0.05 and ***p<0.001 respectively.
Figure 8.
Effect of treatment with GW0742 on parameters of pulmonary hypertension in the chronic hypoxia rat model.
Effect of normoxia versus hypoxia and treatment with GW0742 (30 mg/Kg) versus vehicle control male Sprague-Dawley rats on (A) the ratio of right ventricular to left ventricular plus septal weight and body weight, (B) the right ventricular systolic pressure (RVSP) and (C) the carotid systolic arterial pressure (SAP). The data is mean ± standard error of the mean for n = 4−6 for normoxic animals and 12–17 for hypoxic animals. Data were compared using one-way analysis of variance followed by a Bonferroni's multiple comparison test. Statistical significance was assumed where p<0.05 and is denoted by * and ns (not significant) where p<0.05.
Figure 9.
Effect of normoxia versus hypoxia and treatment with GW0742 (30 mg/kg) versus vehicle control on lung morphology and arteriole mascularisation in male Sprague-Dawley rats.
Sections were stained with Van Giessen stain and pictures shown are representative samples. Histological features of remodelling secondary to hypoxia are the presence of a clear double elastic lamina and increased smooth muscle staining (indicated by arrows). Lungs were from animals in (A) normoxic, (B) normoxic treated with GW0742, (C) hypoxic or (D) hypoxic treated with GW0742 conditions. (E) Total number of fully muscularised compared with partially muscularised pulmonary arterioles in a single lung slice, mean ± standard error of the mean for n = 4−6 for normoxic animals and 12–17 for hypoxic animals.
Table 1.
Biometric data.