Evaluation of newly developed α_1 -adrenoceptor antagonists using COS-7 cells expressing α_1 receptor subtype

Recently human α_1C receptor mRNA has been identified as the predominant subtype in stroma of human prostate. The dynamic-stromatal component of obstruction caused by benign prostatic hyperplasia has been successfully treated pharmacologically with a certain group of α_1 -adrenoceptor antagonists such as alfuzosin, doxazosin, terazosin and YM 671. Utilizing COS-7 cells expressing α_1A , α_1B and α_1C adrenoceptor subtypes, we compared the selectivity of these α_1 antagonists in radioligand binding studies with 「^^125 I」HEAT. All antagonists examined are very potent to all three receptor subtypes, but are not selective enough for a certain subtype.