Alberts P
Department of Pharmacology, Pharmacia Pharmaceuticals, Uppsala, Sweden.
Pharmacol Toxicol. 1995 Aug;77(2):95-101. doi: 10.1111/j.1600-0773.1995.tb00996.x.
The subtype of the functional presynaptic autoreceptor in adrenergic nerves of the male guinea-pig urethra was pharmacologically characterised. The urethra was incubated with 3H-noradrenaline and superfused with Tyrode solution in vitro and the fractional secretion of 3H-noradrenaline evoked by 300 electrical shocks at 5 Hz was measured. alpha-Adrenoceptor antagonists enhanced the 3H-noradrenaline secretion. The effects of BRL 44408 ((+/-)-2-[(4,5-dihydro-1H-imidazol-2yl)methyl]-2,3- dihydro-1-methyl-1H-isoindole), BRL 41992 ((-)-1,2-dimethyl-2,3,9,13b-tetrahydro-1H-dibenzo[c,f]imidazo[1,5- a] azepine), and WB-4101 (2-([2,6-dimethoxyphenoxyethyl]aminomethyl)-1,4- benzodioxane) were tested. The rank order of apparent EC50 values was BRL 44408 < BRL 41992 < WB-4101, and correlated best with constants for the alpha 2A-C10/alpha 2A adrenoceptor subtype. The results suggest that 3H-noradrenaline secretion in guinea-pig urethra is regulated by a presynaptic adrenoceptor of the alpha 2A subtype.
对雄性豚鼠尿道肾上腺素能神经中功能性突触前自身受体的亚型进行了药理学特征分析。将尿道与3H-去甲肾上腺素一起孵育，并在体外以台氏液进行灌流，测量5Hz频率下300次电刺激诱发的3H-去甲肾上腺素的分泌分数。α-肾上腺素能受体拮抗剂增强了3H-去甲肾上腺素的分泌。测试了BRL 44408（（±）-2-[(4,5-二氢-1H-咪唑-2-基)甲基]-2,3-二氢-1-甲基-1H-异吲哚）、BRL 41992（（-）-1,2-二甲基-2,3,9,13b-四氢-1H-二苯并[c,f]咪唑并[1,5-a]氮杂卓）和WB-4101（2-([2,6-二甲氧基苯氧基乙基]氨基甲基)-1,4-苯并二恶烷）的作用。表观EC50值的顺序为BRL 44408 < BRL 41992 < WB-4101，且与α2A-C10/α2A肾上腺素能受体亚型的常数相关性最佳。结果表明，豚鼠尿道中3H-去甲肾上腺素的分泌受α2A亚型突触前肾上腺素能受体的调节。
