Changes in plasma levels of cyclic nucleotides during low-density lipoprotein apheresis

In vitro Treatment with cis-[Ru(H-dcbpy-)2(Cl)(NO)] Improves the Endothelial Function in Aortic Rings with Endothelial Dysfunction

PURPOSE

The ruthenium complex cis-[Ru(H-dcbpy-)2(Cl)(NO)] (DCBPY) is a nitric oxide (NO) donor and studies suggested that the ruthenium compounds can inactivate O2-. The aim of this study is to test if DCBPY can revert and/or prevent the endothelial dysfunction.

METHODS

Normotensive (2K) and hypertensive (2K-1C) wistar rats were used. To vascular reactivity study, thoracic aortas were isolated, rings with intact endothelium were incubated with: DCBPY: 0.1; 1 and 10μM, DCBPY plus hydroxocobalin (NO scavenger) or tempol during 30 minutes, and concentration effect curves to acetylcholine were performed. The potency values (pD2) and maximum effect (ME) were analyzed. The O2- was generated using hypoxantine xantine oxidase and the reduction of cytochrome c, NO consumption by O2- and the effect in avoid NO consumption was measured.

RESULTS

In 2K-1C DCBPY at 0.1; 1 or 10μM improved the relaxation endothelium dependent induced by acetylcholine in aortic rings compared to control 2K-1C, and also improved ME. In rings from 2K incubation with DCBPY (0.1; 1.0 and 10 μM) did not change pD2 or ME. Incubation with 0.1 μM of DCBPY plus hydroxocobalamin did not modify the potency and ME in 2K-1C compared to DCBPY (0.1 μM). DCBPY and SOD inhibits the reduction of cytochrome c and inhibited the NO consumption by O2-, showing that O2- has been removed from the solution.

CONCLUSION

Our results suggest that DCBPY at a lower concentration (0.1 µM) is not an NO generator, but can inactivate superoxide and improves the endothelial function.