Final answer:
Eosinophils regulate vascular mediators released from mast cells by producing interleukins, which are cytokines that modulate the immune response.
Step-by-step explanation:
In regulating vascular mediators released from mast cells, the role of eosinophils prominently includes the release of interleukins. Interleukins are among the various cytokines that immune cells release to modulate the immune response. While mast cells are known for releasing histamine, leukotrienes, and prostaglandins during inflammatory responses, eosinophils produce interleukins which can help modulate the activity of other immune cells and regulate the inflammatory response. Prostaglandins and leukotrienes are other inflammatory mediators released by mast cells that contribute to vasodilation and increased vascular permeability, while histamine is a potent vasodilator released by mast cells for increasing blood flow and capillary permeability, leading to the symptoms of swelling in inflammation.