Up-regulation of α1-adrenoceptors in burn and keloid scars.

Stimulation of α1-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 α1-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 α1-adrenoceptors. In addition, expression of α1-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 α1-adrenoceptors could alter circulatory dynamics both in burn and keloid scars. In addition, the augmented expression of α1-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.