Costello P B, Caruana J A, Green F A
Arthritis Rheum. 1984 Apr;27(4):422-6. doi: 10.1002/art.1780270409.
The rate of aspirin (acetylsalicylic acid, ASA) deacetylation to salicylate in vivo determines the availability of the intact molecule for therapeutically important transacetylation reactions. Experiments were carried out to assess the relative contribution of a previously isolated human erythrocyte ASA esterase to the overall hydrolysis rate in vivo, as opposed to similar enzymes in other tissues. In vitro, the rates of ASA hydrolysis were relatively slow in plasma from humans and dogs. The hydrolysis rates were significantly greater in whole blood in dogs, rabbits, and humans. In human and canine whole blood, the rate of hydrolysis correlated positively with hematocrit. In vivo studies with dogs showed that ASA decay rates conform to a 2-compartment model. After reduction of hematocrit by a mean of 49% in 4 dogs without previous splenectomy, the "availability" of ASA increased. In 4 dogs with previous splenectomy, this measurement was increased even more after comparable hematocrit reduction. In 2 dogs that underwent a sub-total hepatectomy, ASA availability increased by only 35% and 12.8%, respectively. These results suggest a significant role for the erythrocyte esterase in vivo in the dog and possibly in humans.
阿司匹林（乙酰水杨酸，ASA）在体内脱乙酰化为水杨酸的速率决定了完整分子用于具有治疗重要性的转乙酰化反应的可用性。开展实验以评估先前分离出的人红细胞ASA酯酶相对于其他组织中类似酶对体内总体水解速率的相对贡献。在体外，人和犬血浆中ASA的水解速率相对较慢。在犬、兔和人的全血中，水解速率显著更高。在人和犬的全血中，水解速率与血细胞比容呈正相关。对犬进行的体内研究表明，ASA的衰减速率符合二室模型。在4只未行脾切除术的犬中，血细胞比容平均降低49%后，ASA的“可用性”增加。在4只先前已行脾切除术的犬中，血细胞比容可比降低后，这一测量值增加得更多。在2只接受次全肝切除术的犬中，ASA的可用性分别仅增加了35%和12.8%。这些结果表明，红细胞酯酶在犬体内以及可能在人体内发挥着重要作用。
