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Metabolism of small multiple doses of ( 14 C) nicotine in the cat
Author(s) -
TURNER D. M.
Publication year - 1971
Publication title -
british journal of pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0007-1188
DOI - 10.1111/j.1476-5381.1971.tb08050.x
Subject(s) - cotinine , nicotine , chemistry , metabolism , endocrinology , urine , excretion , medicine , urinary system , zoology , biochemistry , biology
Summary1 The distribution and metabolism of (2′‐ 14 C) nicotine given as a series of small intravenous injections (4 μg/kg every 60 s for 20 min) have been studied in the cat. 2 Blood concentrations of ( 14 C) nicotine reached a maximum of 100 ng/ml at 20 min whereas blood concentrations of cotinine were maximal shortly afterwards. 3 The maximum concentration of nicotine in the blood was greater than that obtained by giving the same total dose as a continuous infusion ((4 μg/kg)/min for 20 min). 4 Urinary excretion accounted for 90% of the total multiple dose in 72 hours. After 24 h, however, only 2.5% of the radioactivity as ( 14 C) nicotine and 0.05% as ( 14 C) cotinine was excreted. 5 Gastric juice after 2 h contained significant amounts of activity which was almost entirely composed of ( 14 C) nicotine and ( 14 C) cotinine. 6 There were significant regional differences in the concentration of ( 14 C) nicotine in the brain; amounts were greatest in cerebral hemispheres and smallest in the spinal cord. The hypothalamus and thalamus contained significantly higher concentrations of ( 14 C) nicotine than the whole mid brain. ( 14 C) Cotinine concentrations were highest in the cerebellum.