Evaluation of Evans Blue extravasation as a measure of peripheral inflammation

Plasma extravasation is one of the characteristic symptoms of an in ammatory response and of neurogenic in ammation, a phenomenon which occurs following nerve damage, and can lead to signi cant changes in the control of the cutaneous circulation 1 .Evans Blue binds with high a nity to serum albumin, and the complex has been often used to quantitatively assess the extent of extravasation that accompanies peripheral and neurogenic in ammation 2,3 .Here we present a protocol for evaluating Evans Blue extravasation in rodents with the aid of local application of capsaicin to initiate a neurogenic response exciting the local nociceptors, causing pain, axon re ex vasodilatation and plasma extravasation due to local release of in ammatory mediators.The method is inexpensive, precise and e cient, and can be adapted to assess extravasation in a range of experimental pathological conditions such as parotitis 4 or craniofacial muscle in ammation 5 , and their dependence on different proteins, receptors or pharmacological treatments [6][7][8][9] , in addition to those eliciting neurogenic in ammation.