Three common haplotypes in the gene encoding catechol-O-methyltransferase (COMT) have been associated with pain modulation and the risk of developing chronic musculoskeletal pain, namely temporomandibular disorder (TMD). Haplotypes coding for higher enzymatic activity were correlated with lower pain perception. Rodent studies showed that COMT inhibition increases pain sensitivity through beta2/3-adrenergic receptors. We hypothesized that the nonselective beta-adrenergic antagonist propranolol will reduce clinical and experimental pain in TMD patients in a manner dependent on the individuals' COMT diplotype.
[ hide abstract ]