Shedding light on vascular permeability during peritonitis: role of mast cell histamine versus macrophage cysteinyl leukotrienes.

The inflammatory response consists of sequential steps that are essentially the same whatever the cause and wherever the site. The main purpose of inflammation is to bring fluid, proteins, and cells from the blood into the damaged tissues. Therefore there are mechanisms that allow cells and proteins to gain access to extravascular sites, where and when they are needed if damage and infection has occurred. A critical process for formation of inflammatory exudate is an increase in permeability of local blood vessels. Vasopermeability changes can be usually attributed to mast cells and their mediators but recent studies reveal that also macrophages can be involved in this process. This short commentary discusses new data on cellular origin of major vasoactive mediators, and their receptors during peritoneal inflammation in mice.