Nebivolol combined with tetrahydrobiopterin affects diastolic function in spontaneously hypertensive rats via the nitric oxide/cyclic guanosine monophosphate signalling pathway

Figures

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  Fig. 1. Comparison of cardiac function by colour ultrasound. a E and A peaks in each group. b Comparison of E ‘/A’ among each treatment group and the control group

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  Fig. 2. Application of HPLC to determine the content of BH4 and BH4/BH2 inmyocardium. a The content of BH4 in myocardium, BH4 treatment significantly increased myocardial BH4. b BH4/BH2 in myocardium, although nebivolol monotherapy did not improve myocardium BH4/BH2 ratio,but nebivolol combined with BH4 treatment significantly increased the BH4/BH2 ratio. *P < 0.01 versus Control, # p < 0.01 versus L-N&L-BH4

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  Fig. 3. The concentration of 3-NT in myocardium. BH4 combined with nebivolol significantly inhibited oxidative stress levels. *P < 0.01 versus Control, # p < 0.01 versus L-N&L-BH4

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  Fig. 4. eNOS and eNOS dimer expression in myocardium. a The relative mRNA of eNOS in myocardium, BH4 combined with nebivolol treatment can significantly increase myocardial eNOS mRNA expression. b The relative protein expression of eNOS in myocardium, BH4 combined with nebivolol treatment can significantly increase the expression of eNOS protein in myocardium. c The relative protein expression of eNOS in myocardium. d The relative protein expression of eNOS dimer in myocardium. e eNOS activity in myocardium, high-dose BH4 combined with high-dose nebivolol can significantly increase eNOS activity. f The production of NO in myocardium .*P < 0.01 versus Control, # p < 0.01 versus L-N&L-BH4

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  Fig. 5. Expression of SERCA2a and PLN in each group of myocardium. a The relative expression of PLN mRNA in myocardium. b The relative expression of SERCA2a m RNA in myocardium

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  Fig. 6. BH4 combined with Nebivolol promote the expression level of cGMP in myocardium. a The expression of cGMP in myocardium was detected by immunohistochemistry (n = 20), and the scale was 100 μm. b Statistics of cGMP expression in the myocardium, the data are expressed as the mean density of Image-Pro plus. c The expression of cGMP in myocardium was detected by ELISA.*P < 0.01 versus Control, # p < 0.01 versus L-N&L-BH4

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  Fig. 7. NO/cGMP pathway in cardiomyocytes. NO in the body is produced from L-arginine as a raw material, which is transported into the cell via the cell membrane arginine transporter, and is produced under the action of NOS. The production of NO then activates soluble guanylate cyclase and catalyses the formation of cGMP. The formed cGMP activates PKG. Phosphodiesterase 5 is responsible for the decomposition of cGMP produced by soluble guanylate cyclase, while Phosphodiesterase 9 is responsible for the decomposition of cGMP produced by pGC. The drug stimulates the production of a second messenger cAMP via a Gs-coupled β-adrenergic receptor. cAMP activates PKA, and PKA thenactivates K + channels also increases hyperpolarization, thus indirectly preventing extracellular Ca2 + influx and promoting vasodilation. Abbreviations: cGMP:Cyclic guanosine monophosphate; eNOS: Endothelial nitric oxide synthase; NOS: Nitric oxide synthase; PKA: cAMP-dependent protein kinase; PKG: cGMP-dependent protein kinase; 5’GMP:Guanosine 5′-monophosphate; SERCA2a: Sarco/endoplasmic reticulum Ca2 + −ATPase, SR: Sarco/endoplasmicreticulum, RyR2: Ryanodine receptor 2