The effects of SB 216469, an antagonist which discriminates between the α1A‐adrenoceptor and the human prostatic α1‐adrenoceptor

摘要: 1. The affinity of the alpha 1-adrenoceptor antagonist SB 216469 (also known as REC 15/2739) has been determined at native and cloned subtypes by radioligand binding functional in isolated tissues. 2. In studies with [3H]-prazosin, had a high 1A-adrenoceptors rat cerebral cortex kidney (9.5-9.8) but lower 1B-adrenoceptors spleen liver (7.7-8.2). 3. At transiently expressed COS-1 cells also human stably transfected Rat-1 cells, exhibited 1a-adrenoceptors (9.6-10.4) significantly 1b-adrenoceptor (8.0-8.4) an intermediate 1d-adrenoceptor (8.7-9.2). 4. 1-adrenoceptors, similar pharmacological profile, vas deferens anococcygeus muscle (pA2 = 9.5-10.0), low (6.7) guinea-pig aorta (8.0), 1D-adrenoceptors (8.8). 5. Several recent have concluded that present prostate characteristics 1A-adrenoceptor subtype. However, prostatic 1-adrenoceptors 8.1) tissue strips, was than values obtained either (human, rat, bovine) or rat. 6. Our results 216469, therefore, suggest mediating contractile responses properties which distinguish it from 1a-adrenoceptor 1A-adrenoceptor. Since previously shown receptor is not 1B- 1D-adrenoceptor, may represent novel differ any currently defined means.