US EPA

2917963 

Journal Article 

The effects of phenobarbital, 3-methylcholanthrene and benzo(a)pyrene on the hydrolysis of xenobiotics in the rat 

Kaur, S; Ali, B 

1983 

Yes 

Biochemical Pharmacology
ISSN: 0006-2952
EISSN: 1873-2968 

32 

22 

3479-3480 

English 

6316983 

10.1016/0006-2952(83)90379-9 

WOS:A1983RU04500031 

The effects of phenobarbital (50066), 3-methylcholanthrene (56495) and benzo(a)pyrene (50328) on the activities of esterase/amidase catalyzing hydrolytic metabolism of xenobiotics was investigated in rat tissue. Albino-rats were given 80 milligrams per kilogram of the chemicals intraperitoneally for 6 consecutive days. Animals were sacrificed 18 to 20 hours later and liver, lung, kidney, intestine, and brain tissue were removed. The activities of acetylsalicylic-acid esterase, procaine esterase, p-nitrophenyl-acetate esterase, acetanilid N-deacetylase, and cholinesterase in liver microsomes and tissue homogenates were determined. The rate of 2-acetylaminofluorene hydrolysis was measured. There was marked stimulation of hepatic microsomal carboxylesterases/amidases necessary for hydrolytic metabolism of acetylsalicylic-acid, procaine, p-nitrophenylacetate, acetanilid, and 2-acetylaminofluorene in rats pretreated with phenobarbital. Cholinesterase activity did not change. Enzyme activity in other tissues was not changed. Administration of 3-methylcholanthrene or benzo(a)pyrene did not affect enzyme activity in any tissue. The authors conclude that phenobarbital is a potent inducer of hepatic microsomal esterases and amidases.