Affinity of trazodone for human penile α1- and α2-adrenoceptors

Objective To determine the affinities of human penile alpha-adrenoceptors and cloned human alpha-adrenoceptor subtypes for trazodone, an antidepressant with reported beneficial effects in erectile dysfunction. Materials and methods Competition radioligand binding studies were performed with trazodone in human penile tissue and in cell lines stably expressing all cloned human alpha-adrenoceptor subtypes. Results Trazodone had higher affinity for human alpha(1)-adrenoceptors (10-130 nmol/L) than for alpha(2)-adrenoceptors (300-700 nmol/L), but did not discriminate between subtypes of human alpha(1)- or alpha(2)-adrenoceptors. Conclusion Trazodone has high and moderate affinity for human alpha(1)- and alpha(2)-adrenoceptors, respectively; this might contribute to its reported beneficial effects in erectile dysfunction.