Dreyfuss J, Singhvi S M, Shaw J M, Egli P, Ross J J, Czok R, Nefzger-Biessels M, Battig F, Schuster I, Schmook F
J Antibiot (Tokyo). 1979 May;32(5):496-503. doi: 10.7164/antibiotics.32.496.
The metabolism of tiamulin hydrogen fumarate, labeled with 3H, 14C, or both, was studied in dogs, rats, and weanling pigs. After a dose of radiolabeled tiamulin, all three species excreted more radioactivity in feces (via bile) than in urine. Dogs absorbed 86% of a single oral dose of tiamulin-3H, and the disposition of the compound was similar after a single or multiple dosage regimen. The ratio of antimicrobial activity to total radioactivity in dog plasma was only about 0.25, and was still less in dog urine. After dosing with tiamulin-14C, rats and pigs excreted at least 1% of the dose as 14CO2 in expired air. In dual-labeled studies, pigs excreted less total 14C than 3H and had greater residues of 14C than 3H in edible tissues, blood, and plasma. After the administration of tiamulin-14C to pigs, radioactivity was incorporated into liver glycogen, indicating metabolic cleavage of the side chain of tiamulin. Tiamulin-3H is the isotopically-labeled compound of choice for studying metabolism and tissue residues in animals.
研究了用³H、¹⁴C或两者标记的富马酸泰妙菌素在犬、大鼠和断奶仔猪体内的代谢情况。给予放射性标记的泰妙菌素后，这三种动物通过粪便（经胆汁）排出的放射性都比尿液中多。犬单次口服泰妙菌素 - ³H后，吸收了86%的剂量，单次或多次给药后该化合物的处置情况相似。犬血浆中抗菌活性与总放射性的比值仅约为0.25，犬尿液中的该比值更低。给予泰妙菌素 - ¹⁴C后，大鼠和猪呼出的气体中至少有1%的剂量以¹⁴CO₂的形式排出。在双标记研究中，猪排出的¹⁴C总量低于³H，且在可食用组织、血液和血浆中的¹⁴C残留量高于³H。给猪施用泰妙菌素 - ¹⁴C后，放射性被整合到肝糖原中，表明泰妙菌素侧链发生了代谢裂解。泰妙菌素 - ³H是研究动物体内代谢和组织残留的首选同位素标记化合物。
