Affinity of trazodone for human penile alpha(1)- and alpha(2)-adrenoceptors

Objective To determine the affinities of human penile alpha-adrenoceptors a nd cloned human alpha-adrenoceptor subtypes for trazodone, an antidepressan t with reported beneficial effects in erectile dysfunction. Materials and methods Competition radioligand binding studies were performe d 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 d iscriminate 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 reporte d beneficial effects in erectile dysfunction.