TROPINE-LABELED ATROPINE METABOLISM IN MAN N-C14H3-ATROPINE
PITTSBURGH UNIV PA SCHOOL OF MEDICINE
Pagination or Media Count:
The excretion of the C14 in the urine and expired air, and the disappearance of the C14 from the blood after an intramuscular injection of 2 mg. are discussed in this report. Chromatographic analysis of urinary components is incomplete, but preliminary data suggests that most of the label is present in the urine as unchanged atropine and as its hydrolysis product, tropine. A total of 88 of the injected dose was collected in the urine in 48 hours. A unique finding was the occurrence of C14 in the expired air, indicative of a demethylation being one of the metabolic pathways for atropine in man. Approximately 3 of the injected dose was recovered in the expired air in the 3 hours during which samples were taken. Blood levels were extremely low, indicative of avid tissue binding of the drug, but did seem to reach a maximum at 30 minutes after injection, a time at which maximum tachycardia was also observed. Expired air C14O2 showed a maximum at 75 minutes, while the peak urinary concentration occurred at 3 hours.