Biomaterial Database

Metabolism of benzo(a)pyrene by guinea pig pancreatic microsomes. 1977

Z M Iqbal, and M E Varnes, and A Yoshida, and S S Epstein

The in vitro microsomal metabolism of the strain 13 guinea pig pancreas was investigated by determining the benzo(a)pyrene (BP) hydroxylase activity in the 9000 x g supernatant and microsomal pellet. BP hydroxylase activity in both 9000 x g supernatant and microsomal pellet of the pancreas was less than 1% of the activity in the respective liver fractions, However, pretreatment of animals with methylcholanthrene or BP at 20 mg/kg, for either 1 day or 3 consecutive days, markedly enhanced the BP hydroxylase activity of pancreatic microsomes over that of controls; the induction in the liver microsomes was less than 2-fold over that of controls. The hydroxylation of BP by pancreatic microsomes was linear with time over a 30-min period, with the rate of hydroxylation dependent on both the enzyme and substrate concentrations.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008099	Liver	A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.	Livers
D008297	Male		Males
D008748	Methylcholanthrene	A carcinogen that is often used in experimental cancer studies.	20-Methylcholanthrene,3-Methylcholanthrene,20 Methylcholanthrene,3 Methylcholanthrene
D008861	Microsomes	Artifactual vesicles formed from the endoplasmic reticulum when cells are disrupted. They are isolated by differential centrifugation and are composed of three structural features: rough vesicles, smooth vesicles, and ribosomes. Numerous enzyme activities are associated with the microsomal fraction. (Glick, Glossary of Biochemistry and Molecular Biology, 1990; from Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed)	Microsome
D008862	Microsomes, Liver	Closed vesicles of fragmented endoplasmic reticulum created when liver cells or tissue are disrupted by homogenization. They may be smooth or rough.	Liver Microsomes,Liver Microsome,Microsome, Liver
D010179	Pancreas	A nodular organ in the ABDOMEN that contains a mixture of ENDOCRINE GLANDS and EXOCRINE GLANDS. The small endocrine portion consists of the ISLETS OF LANGERHANS secreting a number of hormones into the blood stream. The large exocrine portion (EXOCRINE PANCREAS) is a compound acinar gland that secretes several digestive enzymes into the pancreatic ductal system that empties into the DUODENUM.
D004790	Enzyme Induction	An increase in the rate of synthesis of an enzyme due to the presence of an inducer which acts to derepress the gene responsible for enzyme synthesis.	Induction, Enzyme
D006168	Guinea Pigs	A common name used for the genus Cavia. The most common species is Cavia porcellus which is the domesticated guinea pig used for pets and biomedical research.	Cavia,Cavia porcellus,Guinea Pig,Pig, Guinea,Pigs, Guinea
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia