在兔子上研究了水杨酸-L-丙氨酸结合物(水杨丙氨酸)口服、静脉注射、盲肠内和直肠给药(分别为60、10、5和5 mg kg−1,以水杨酸当量计)后的水解情况。口服给药水杨丙氨酸后2小时在血液中检测到水杨酸,并在10小时达到最大浓度,而水杨丙氨酸则迅速消除。相比之下,静脉注射水杨丙氨酸后仅发现未改变的水杨丙氨酸,这表明水杨丙氨酸的预系统解结合作用。在带有完整肠系膜静脉血收集的肠道原位袋准备中,未识别出水杨丙氨酸的肠粘膜解结合作用。在盲肠内给药水杨丙氨酸后,立即在盲肠中发现大量水杨酸的形成。在兔子口服硫酸卡那霉素预处理后,观察到在盲肠内给药水杨丙氨酸后水杨酸形成显著抑制,表明肠道微生物负责水杨丙氨酸的生物转化。将水杨丙氨酸与肠道内容物进行体外培养,发现其水解的主要来源是后肠。因此,在直肠给药水杨丙氨酸后,水杨酸的血液浓度显著延长,这表明水杨丙氨酸作为水杨酸的前药具有潜在的有用性。
The hydrolysis of salicylic acid-l-alanine conjugate (salicyl-l-alanine) following oral, intravenous, intracaecal and rectal administration (60, 10, 5 and 5 mg kg−1, respectively: salicylic acid equivalent) was examined in rabbits. Salicylic acid was detected in the blood 2 h after oral administration of salicyl-l-alanine and reached a maximum concentration at 10 h, whereas salicyl-l-alanine was rapidly eliminated. In contrast, unchanged salicyl-l-alanine only was found following intravenous administration of salicyl-l-alanine, suggesting that presystemic de-conjugation of salicyl-l-alanine was involved. The intestinal mucosal de-conjugation of salicyl-l-alanine was not recognized in the in-situ intestinal sac preparation with complete mesenteric venous blood collection. Immediate and very extensive salicylic acid formation in the caecum was found following intracaecal administration of salicyl-l-alanine. After oral pretreatment of rabbits with kanamycin sulphate, a significant inhibition of salicylic acid formation following intracaecal administration of salicyl-l-alanine was observed, indicating that the intestinal microorganisms were responsible for the biotransformation of salicyl-l-alanine. In-vitro incubation of salicyl-l-alanine with gut contents showed that the major source of its hydrolysis was the hind gut. Consequently, the blood concentration of salicylic acid was prolonged extensively following rectal administration of salicyl-l-alanine, suggesting the usefulness of salicyl-l-alanine as a prodrug of salicylic acid.
在兔子上研究了水杨酸-L-丙氨酸结合物(水杨丙氨酸)口服、静脉注射、盲肠内和直肠给药(分别为60、10、5和5 mg kg−1,以水杨酸当量计)后的水解情况。口服给药水杨丙氨酸后2小时在血液中检测到水杨酸,并在10小时达到最大浓度,而水杨丙氨酸则迅速消除。相比之下,静脉注射水杨丙氨酸后仅发现未改变的水杨丙氨酸,这表明水杨丙氨酸的预系统解结合作用。在带有完整肠系膜静脉血收集的肠道原位袋准备中,未识别出水杨丙氨酸的肠粘膜解结合作用。在盲肠内给药水杨丙氨酸后,立即在盲肠中发现大量水杨酸的形成。在兔子口服硫酸卡那霉素预处理后,观察到在盲肠内给药水杨丙氨酸后水杨酸形成显著抑制,表明肠道微生物负责水杨丙氨酸的生物转化。将水杨丙氨酸与肠道内容物进行体外培养,发现其水解的主要来源是后肠。因此,在直肠给药水杨丙氨酸后,水杨酸的血液浓度显著延长,这表明水杨丙氨酸作为水杨酸的前药具有潜在的有用性。