Pyridine appears as a clear colorless to light yellow liquid with a penetrating nauseating odor. Density 0.978 g / cm3. Flash point 68°F. Vapors are heavier than air. Toxic by ingestion and inhalation. Combustion produces toxic oxides of nitrogen.
8 ANIMAL SPECIES N-METHYLATED PYRIDINE WHICH WAS EXTENSIVE (20-40% DOSE) IN CAT, GUINEA PIG, GERBIL, RABBIT, & HAMSTER, BUT LOW (5-12% DOSE) IN RAT, MOUSE, & 2 HUMAN VOLUNTEERS. PATTERN OF N-METHYLATION SIMILAR FROM ORAL & IP ROUTES IN RATS & GUINEA PIGS & WAS DOSE-DEPENDENT.
PART IS EXCRETED IN URINE ... IN FORM OF ITS CHIEF METABOLITE, N-METHYLPYRIDINIUM HYDROXIDE. PYRIDINE IS EXAMPLE OF METHYLATION PROCESS OF METABOLISM ... CONFINED TO SOME HETEROCYCLIC COMPOUNDS ... THIS OCCURS, WITH PYRIDINE, ONLY IN SOME ANIMALS ... MICE, BUT NOT IN RATS ... IN RABBITS ONLY TRACES OF 3-HYDROXY PYRIDINE ARE EXCRETED.
An organism capable of growth on pyridine was isolated from soil by enrichment culture techniques and identified as Micrococcus luteus. The organism oxidized pyridine for energy and released nitrogen contained in the pyridine ring as ammonium. Cell extracts of M luteus could not degrade pyridine, 2-, 3-, or 4-hydroxypyridines or 2,3-dihydroxypyridine, regardless of added cofactors or cell particulate fraction. The organism had a NAD-linked succinate-semialdehyde dehydrogenase which was induced by pyridine. Cell extracts of M luteus had constitutive amidase activity, and washed cells degraded formate and formamide without a lag. ... The results provide new evidence that the metabolism of pyridine by microorganisms does not require initial hydroxylation of the ring and that permeability barriers do not account for the extremely limited range of substrate isomers used by pyridine degraders.
The oxidative metabolism of pyridine was studied in vitro. Normal human liver, lung, and kidney tissue /were/ obtained from ten persons ... and liver tissue from male Fischer 344 rats. ... The primary metabolites identified were 2-pyridone, 4-pyridone, and pyridine-N-oxide (PNO). Human liver and kidney microsomes formed these metabolites at rates of 154 to 275 pmol/min/mg. Liver microsomes from one subject formed 3-hydroxypyridine-N-oxide at a rate of 133 pmol/min/mg. The formation of 4-pyridone was significantly greater in liver microsomes from the males than from the females. Human lung microsomes formed 2-pyridone, 4-pyridone, and pyridine-N-oxide at rates of 63 to 110 pmol/min/mg. The rates of formation of 2-pyridone, 4-pyridone, and pyridine-N-oxide by rat liver microsomes ranged from 17 to 61 pmol/min/mg. Incubation of human liver microsomes under the nitrogen and carbon monoxide atmosphere and in the presence of metyrapone reduced pyridine metabolism by 54, 34, and 20%, respectively. SKF-525A, allopurinol, and n-octylamine did not signifiantly affect pyridine metabolism. Human and rat liver cytosol did not metabolize pyridine. /Results suggest/ that human liver, kidney, and lung microsomes and rat liver microsomes can metabolize pyridine under aerobic conditions in the presence of a NADPH generating system. The cytochrome p450 monooxygenase system appears to be responsible for the metabolism of pyridine by human liver microsomes.
来源:Hazardous Substances Data Bank (HSDB)
毒理性
致癌性证据
A3:已确认的动物致癌物,对人类的相关性未知。
A3: Confirmed animal carcinogen with unknown relevance to humans.
Pyridine is absorbed from the gastrointestinal tract, through the skin, and by inhalation. Part of the absorbed pyridine is excreted in the urine unchanged and a smaller portion is methylated at the N position.
Uptake by tissues /in rats/ following ip admin of pyridine increased with dosage. Elimination occurred in 2 phases and the duration of these phases was also dose dependent.
来源:Hazardous Substances Data Bank (HSDB)
吸收、分配和排泄
IP ADMIN TO MICE, HAMSTERS, RATS, GUINEA PIGS, RABBITS, & FERRETS RESULTED IN URINARY EXCRETION OF PYRIDINE N-OXIDE WHICH RANGED FROM 10% IN RATS TO APPROX 40% IN MICE & GUINEA PIGS.
对小鼠、仓鼠、大鼠、豚鼠、兔子和雪貂进行IP(腹腔注射)给药,导致尿液中排出吡啶N-氧化物,在大鼠中的排出率约为10%,而在小鼠和豚鼠中的排出率大约为40%。
IP ADMIN TO MICE, HAMSTERS, RATS, GUINEA PIGS, RABBITS, & FERRETS RESULTED IN URINARY EXCRETION OF PYRIDINE N-OXIDE WHICH RANGED FROM 10% IN RATS TO APPROX 40% IN MICE & GUINEA PIGS.
1.周国泰,化学危险品安全技术全书,化学工业出版社,1997 2.国家环保局有毒化学品管理办公室、北京化工研究院合编,化学品毒性法规环境数据手册,中国环境科学出版社.1992 3.Canadian Centre for Occupational Health and Safety,CHEMINFO Database.1998 4.Canadian Centre for Occupational Health and Safety, RTECS Database, 1989