Studies on modifiers of microsomal drug oxidation

Details

• Personal Author:
  Leibman KC
• Description:
  Studies on modifiers of hepatic microsomal drug metabolism were summarized. The effect of metyrapone (54364), a potent adrenal steroid hydroxylase inhibitor, on hepatic microsomal acetanilide- hydroxylase (AcOHase) was described. Metyrapone exerted a biphasic effect, moderate doses being stimulatory and high doses being inhibitory. Similar biphasic effects on AcOHase or aniline- hydroxylase (AnOHase) have been observed with acetone (67641), acetophenone (98862), alpha,alpha'-dipyridyl (366187) (AADP), and o- phenanthroline (66717) (phenanthroline) which all have structural features in common with metyrapone. Other compounds that affect AcOHase, AnOHase, or aminopyrine-demethylase (APDN) such as clofibrate (637070), 2-(p-aminophenyl)-2-phenylethylamine (6578310) (SKF-12185), 1-(2-isopropylphenyl)imidazole (25364403) (IPI), and 1- (2-cyanophenyl)imidazole (25373493) (CPI) were described. Whereas SKF-12185 and clofibrate readily inhibit adrenal steroid hydroxylation, they are rather weak inhibitors of hepatic microsomal AcOHase, AnOHase, or APDN. The concentrations for 50 percent inhibition (IC50) of AcOHase, AnOHase, and APDN are on the order of 1 millimolar. IPI and CPI are very potent inhibitors, the respective IC50s for APDN being 0.5 and 10 micromolar. IPI has been found to prolong hexobarbital sleeping time in rats to about five times the control value and to cause 33 percent mortality. The spectrophotometric properties of metyrapone were discussed. Metyrapone produces a type-II difference spectrum when added to liver microsomes. Acetophenone, AADP, and phenanthroline do not produce a characteristic difference spectrum when added to either oxidized or reduced liver microsomes. The author concludes that the ability of metyrapone to produce a type-II difference spectrum is not related to its effect on AcOHase. [Description provided by NIOSH]
• Subjects:
  Laboratories Occupational Health Safety
• Keywords:
  Absorption-spectrophotometry Drugs Grants-other In-vitro-studies In-vivo-studies Laboratory-animals Liver-microsomal-metabolism NIOSH-Grant NIOSH-Publication Oxidative-processes
• ISSN:
  0009-2797
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article
• Place as Subject:
  Florida ; OSHA Region 4
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  289-290
• Volume:
  3
• Issue:
  4
• NIOSHTIC Number:
  nn:00186811
• Citation:
  Chem-Biol Interact 1971 Aug; 3(4):289-290
• Contact Point Address:
  Pharmacology and Therapeutics Univ of Florida Coll of Med Dept of Pharma & Therapeutics Gainesville, Fla 32601
• CAS Registry Number:
  1,10-Phenanthroline (CAS RN 66-71-7) ; 1-[2-(1-Methylethyl)phenyl]-1H-imidazole (CAS RN 25364-40-3) ; 2-(1H-Imidazol-1-yl)benzonitrile (CAS RN 25373-49-3) ; 2,2′-Bipyridine (CAS RN 366-18-7) ; Acetone (CAS RN 67-64-1) ; Acetophenone (CAS RN 98-86-2) ; Benzeneethanamine, 4-amino-β-phenyl- (CAS RN 6578-31-0) ; Clofibrate (CAS RN 637-07-0) ; Metyrapone (CAS RN 54-36-4)
• Federal Fiscal Year:
  1971
• NORA Priority Area:
  Other Occupational Concerns ; Grants Other
• Performing Organization:
  University of Florida Gainesville, Gainesville, Florida
• Peer Reviewed:
  True
• Start Date:
  19710101
• Source Full Name:
  Chemico-Biological Interactions
• End Date:
  19841130
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:ee1e80272c6c11e27d696b35d4ef69283280630e28b588b6b737994a28e7864d13e667cb8edb1233789049065ad0612de867edf82a14fe88b6cd52600d581449
• Download URL:
  https://stacks.cdc.gov/view/cdc/205634/cdc_205634_DS1.pdf
• File Type:
  [PDF - 114.69 KB ]