Abstract
Binding characteristics of α1-adrenoceptors in the bovine prostate were examined using a radioligand binding assay. [3H] Bunazosin was used as a radioligand. The optimal incubation conditions for the radioligand binding assay were determined : incubation time (30 min), protein concentration (0.2 mg/tube) and temperature (30°C). Scatchard plots for α1-adrenoceptors in bovine prostates were linear and the Kd and Bmax values were 0.61 nM and 49.8 fmol/mg protein, respectively. The pKi value of terazosin was significantly higher than those of prazosin, bunazosin or phentolamine in the bovine prostate. Since this radioligand binding assay using [3H] bunazosin demonstrated the presence of α1-adrenoceptors in bovine prostates, this method is useful for the assessment of α1-blockers of new chemicals synthesized for the treatment of the benign prostatic hyperplasia.
