Species differences in the metabolism of paeonol (2-hydroxy-4-methoxyacetophenone : I) in mice, rats, guinea pigs and rabbits were studied by the RI tracer technique. After the administration of a single dose of 20 mg (6-70μCi)/kg paeonol [carbonyl-14C] (I-14C), radioactive metabolites excreted in the urine were analyzed. The excretion of I-14C was rapid in all species ; that is, about 83-98% of administered radioactivity was excreted in the urine and feces during two days after the administration. The 14C-activity excreted in feces was 10.6% in mice, 4.7% in rats, 2.9% in guinea pigs, and 0.8% in rabbits. It is clear that the urine is the major excretion route in all species. 2, 5-Dihydroxy-4-methoxyacetophenone (II), resacetophenone (III) and unchanged I were detected in all species as urinary metabolites. These metabolites were found as the free form, β-glucuronide, sulfate and enzyme-resistant conjugate. The major metabolite in each species was as follows ; mice, II 43.1% ; rats, II 62.0% ; guinea pigs, III 58.1% ; rabbits, III 42.7% and II 42.2%. All the metabolites were conjugated in rats, while the total amount of unconjugated metabolites was 50-60% of total metabolites in other species. Although β-glucuronide and sulfate in rats accounted for 19.9% and 8.2%, respectively, only small amounts of these conjugated forms were excreted in other species. Enzyme-resistant conjugate accounted for 60.2% in rats, but only 35-43% in other species.
通过 RI 示踪技术研究了小鼠、大鼠、豚鼠和兔子体内芍药
酚(
2-羟基-4-甲氧基苯乙酮:I)代谢的物种差异。单次给药 20 毫克(6-70μCi)/千克芍药
酚[羰基-14C](I-14C)后,对尿液中排出的放射性代谢物进行分析。在所有物种中,I-14C 的排泄速度都很快;也就是说,在给药后两天内,约 83-98% 的给药放射性物质通过尿液和粪便排出体外。小鼠粪便中排出的 14C 活性为 10.6%,大鼠为 4.7%,豚鼠为 2.9%,兔子为 0.8%。显然,尿液是所有物种的主要排泄途径。所有物种的尿液代谢物中都检测到了 2,5-二羟基-4-
甲氧基苯乙酮(II)、间
苯乙酮(III)和未发生变化的 I。这些代谢物以游离态、β-
葡萄糖醛酸苷、
硫酸盐和抗酶共轭物的形式存在。各物种的主要代谢物如下:小鼠,II 43.1%;大鼠,II 62.0%;豚鼠,III 58.1%;兔子,III 42.7%和 II 42.2%。大鼠的所有代谢物都是共轭的,而其他物种的非共轭代谢物总量占代谢物总量的 50-60%。虽然在大鼠体内,β-
葡萄糖醛酸和
硫酸盐分别占 19.9% 和 8.2%,但在其他物种中,这些共轭形式的代谢物仅有少量排出体外。耐酶共轭物在大鼠体内占 60.2%,但在其他物种体内仅占 35-43%。