Benign prostatic hyperplasia: correlations between receptor density and binding affinity of alpha(1)-adrenoceptors...

The aim of the study was to determine whether relations do exist between the concentration and activity of alpha(1)-adrenoceptors, both inside the prostatic adenoma and the periurethral zone corresponding to the bladder neck, and clinical and biological parameters such as symptoms, evaluated by the American Urological Association (AUA) score, age, weight of the prostate, PSA, and the flow rate. Twenty patients with symptomatic benign prostatic hyperplasia were selected for an open prostatectomy. One gram of tissue was dissected from inside the adenoma and 1 g from the periurethral zone corresponding to the bladder neck. The alpha(1)-adrenoceptors were evaluated for the apparent dissociation constant (K(d)) and the maximal number of binding sites (B(max)). A correlation seems to exist between receptor density inside the adenoma and the bladder neck and an inverse correlation between receptor density and the AUA total symptoms score. Finally, a highly significant difference was found in patients with an AUA score of <15 or >15. No relationship was found between receptor binding affinity and the considered clinical parameters.