Up-regulation of α-adrenoceptors in burn and keloid scars.

Stimulation of α-adrenoceptors evokes inflammatory cytokine production, boosts neurogenic inflammation and pain, and influences cellular migration and proliferation. Hence, these receptors may play a role both in normal and abnormal wound healing. To investigate this, the distribution of α-adrenoceptors in skin biopsies of burn scars (N=17), keloid scars (N=12) and unscarred skin (N=17) was assessed using immunohistochemistry. Staining intensity was greater on vascular smooth muscle in burn scars than in unscarred tissue, consistent with heightened expression of α-adrenoceptors. In addition, expression of α-adrenoceptors was greater on dermal nerve fibres, blood vessels and fibroblasts in keloid scars than in either burn scars or unscarred skin. These findings suggest that increased vascular expression of α-adrenoceptors could alter circulatory dynamics both in burn and keloid scars. In addition, the augmented expression of α-adrenoceptors in keloid tissue may contribute to processes that produce or maintain keloid scars, and might be a source of the uncomfortable sensations often associated with these scars.