What is the inflammatory mediator that is specifically linked to causing pain after an injury?

Bradykinin is the inflammatory mediator specifically linked to causing pain after an injury due to its role as a potent pain-producing agent. When tissues are injured, bradykinin is released and it acts on nerve endings to enhance the sensation of pain. It does so by activating specific receptors that promote pain signaling pathways in the peripheral nervous system.

Bradykinin also contributes to the overall inflammatory response, facilitating blood vessel dilation and increasing vascular permeability which leads to swelling in the affected area. This combination of promoting inflammation and directly stimulating nociceptive neurons makes it a critical mediator in the experience of pain following injury.

While other mediators like prostaglandins also play a role in pain and inflammation, bradykinin is more specifically recognized for its direct action on pain pathways. Prostaglandins typically contribute to the sensitization of pain receptors, while histamine serves more in allergic responses and increasing blood flow and nitric oxide primarily acts as a vasodilator. Thus, bradykinin's particular mechanism of enhancing pain perception after an injury distinguishes it as the primary mediator of interest in this context.