Ruffolo R R, Fowble J W, Miller D D, Patil P N
J Pharmacol Exp Ther. 1977 Aug;202(2):278-86.
Azepatine, a potent alpha adrenergic antagonist, was catalytically reduced with tritium and hydrogen gas to form dihydroazapetine. The pA2 azapetine was 7.9 whereas that of dihydroazapetine was 6.6, corresponding to a 20-fold decrease in potency. 3H-dihydroazapetine is accumulated into three kinetically distinct compartment in the denervated rabbit aorta. Likewise, efflux of the labeled antagonist occurs from three compartments. The rat constant for onset of alpha adrenoreceptor blockade is 3.15 min-1 which is nearly identical to the rate constant for entry of 3H-dihydroazapetine into a rapidly filling compartment (3.86 min-1) possibly representing the extracellular space. These data are consistent with the hypothesis that onset of alpha adrenoreceptor blockade by dihydroazapetine is diffusion limited.
阿泽哌汀是一种强效α肾上腺素能拮抗剂，用氚和氢气对其进行催化还原，生成二氢阿泽哌汀。阿泽哌汀的pA2为7.9，而二氢阿泽哌汀的pA2为6.6，这相当于效力降低了20倍。3H-二氢阿泽哌汀在去神经支配的兔主动脉中累积到三个动力学上不同的区室。同样，标记拮抗剂的流出也发生在三个区室。α肾上腺素能受体阻断开始的大鼠常数为3.15 min-1，这与3H-二氢阿泽哌汀进入快速充盈区室（可能代表细胞外空间）的速率常数（3.86 min-1）几乎相同。这些数据与二氢阿泽哌汀引起的α肾上腺素能受体阻断开始是扩散受限的假说一致。
