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- Mason, R Preston, et al.
(författare)
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Loss of arterial and renal nitric oxide bioavailability in hypertensive rats with diabetes : effect of beta-blockers
- 2009
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Ingår i: American Journal of Hypertension. - : Oxford University Press (OUP). - 0895-7061 .- 1941-7225. ; 22:11, s. 1160-1166
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Endothelial cell (EC) dysfunction contributes to hypertension and mechanisms of atherosclerosis. Agents that improve EC function may provide vascular protection, especially in patients with multiple risk factors. In this study, we examined the effects of beta(1)-selective antagonists, nebivolol and metoprolol, on vascular and renal EC function in spontaneously hypertensive (SH) rats with diabetes. METHODS: Male SH rats were treated with streptozotocin (STZ) to induce type 2 diabetes, followed by treatment with nebivolol or metoprolol at 2 mg/kg/day (vs. vehicle). After 4 weeks, aortic and glomerular ECs were isolated, stimulated with calcium ionophore (CaI), and assayed for nitric oxide (NO), and peroxynitrite (ONOO(-)) release using amperometric approaches. RESULTS: Glucose and mean blood pressure (BP) levels were significantly elevated in diabetic SH rats. In aortic ECs isolated from diabetic SH rats, NO production decreased by 20% whereas ONOO(-) increased by 16%, an effect linked to NAD(P)H oxidase and endothelial NO synthase (eNOS) uncoupling. Nebivolol treatment reduced glucose and BP levels and restored aortic EC function in diabetic SH rats, as indicated by a 30% increase and 23% decrease in NO and ONOO(-) levels, respectively. The NO/ONOO(-) ratio increased by more than twofold with nebivolol treatment in aortic and glomerular ECs. Despite similar reductions in glucose and mean BP levels, metoprolol had a smaller effect on the NO/ONOO(-) ratio in glomerular ECs but no effect in aortic ECs. CONCLUSIONS: Vascular and renal NO was significantly reduced in diabetic hypertensive rats and correlated with metabolic changes. Nebivolol reversed these effects in a manner consistent with enhanced endothelial function.
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| 2. |
- Melki, Vilyam, et al.
(författare)
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Effect of Glyceryl Trinitrate on Staphylococcus aureus Growth and Leukocyte Activation during Simulated Extracorporeal Circulation
- 2014
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Ingår i: The thoracic and cardiovascular surgeon. - : Georg Thieme Verlag KG. - 0171-6425 .- 1439-1902. ; 62:5, s. 402-408
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Tidskriftsartikel (refereegranskat)abstract
- Background Previously, nitric oxide has been shown to possess antimicrobial effects. In this study, we aim to test the effect of glyceryl trinitrate (GTN) on Staphylococcus aureus growth during simulated extracorporeal circulation (SECC) and also to examine the effect of S. aureus, alone and in combination with GTN, on activation markers of the innate immune system during SECC. Methods In an in vitro system of SECC, we measured GTN-induced changes in markers of leukocyte activation in whole blood caused by S. aureus infestation, as well as the effect of GTN on S. aureus growth. Results GTN had no effect on S. aureus growth after 240 minutes SECC. Staphylococcus aureus reduced the expression of granulocyte Fc gamma-receptor CD32 but stimulated the expression of monocyte CD32. Staphylococcus aureus stimulated expression of some leukocyte adhesion key proteins, activation marker CD66b, lipopolysaccharide-receptor CD14, and C3b-receptor CD35. Staphylococcus aureus and GTN addition induced significant increases in monocyte CD63 (lysosomal granule protein) levels. Conclusion GTN does not affect S. aureus growth during SECC and has no effect on SECC-induced leukocyte activation.
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