Augmented nitric oxide production and up-regulation of endothelial nitric oxide synthase during cecal ligation and perforation.

Nitric oxide (NO) has been pointed out as being the main mediator involved in the hypotension and tissue injury taking place during sepsis. This study aimed to investigate the cellular mechanisms implicated in the acetylcholine (ACh)-induced relaxation detected in aortic rings isolated from rats submitted to cecal ligation and perforation (CLP group), 6h post-CLP. The mean arterial pressure was recorded, and the concentration-effect curves for ACh were constructed for endothelium-intact aortic rings in the absence (control) or after incubation with one of the following NO synthase inhibitors: L-NAME (non-selective), L-NNA (more selective for eNOS), 7-nitroindazole (more selective for nNOS), or 1400W (selective for iNOS).

Prostacyclin, not only nitric oxide, is a mediator of the vasorelaxation induced by acetylcholine in aortas from rats submitted to cecal ligation and perforation (CLP).

Nitric oxide has been pointed out as the main agent involved in the vasodilatation, which is the major symptom of septic shock. However, there must be another mediator contributing to the circulatory failure observed in sepsis. This study aimed to investigate the endothelium-dependent relaxation induced by acetylcholine and the factors involved in this relaxation, using aortic rings isolated from rats submitted to cecal ligation and perforation (CLP), 2h after induction of sepsis, which characterizes the hyperdynamic phase of sepsis.

The complex trans-[RuCl([15]aneN4NO]2+ induces rat aorta relaxation by ultraviolet light irradiation.

The aim of the present study was to investigate the possible endogenous storage of photosensitive nitric oxide, and also to examine the relaxant effect of NO released from the compound by UV light irradiation. Aorta was isolated from rats and the endothelium was mechanically removed. Denuded aortic rings pre-contracted with prostaglandin F(2alpha) responded with relaxation to UV light irradiation.