These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: SKF 525-A inhibition, induction, and 452-nm complex formation.
    Author: Buening MK, Franklin MR.
    Journal: Drug Metab Dispos; 1976; 4(3):244-55. PubMed ID: 6229.
    Abstract:
    After administration of SKF 525-A to rats a portion of the cytochrome P-450 in hepatic microsomes was found in the reduced form as a stable complex absorbing at 452 nm. As much as 40% of the total cytochrome P-450 was bound in the complexed form after a single administration of SKF 525-A. The addition of potassium ferricyanide (50 muM) to hepatic microsomes from SKF 525-A-treated rats destroyed the complex and made the total cytochrome P-450 available for carbon monoxide binding. At early times after administration of SKF 525-A, when the amount of complexed cytochrome P-450 was maximum, mixed-function oxidase activities (p-nitroanisole O-demethylase and norbenzphetamine 455-nm complex formation) were greatly inhibited. Later, as the amount of complexed cytochrome P-450 slowly decreased, these mixed-function oxidase activities gradually returned and reached control values in about 48 hr. Induction with daily doses of SKF 525-A for several days increased total cytochrome P-450 content up to 5-fold, which was more than induction with phenobarbital, but this was evident only after destruction of the complex with ferricyanide. The maximum increase in uncomplexed cytochrome P-450 was only 2-fold. Treatment of these microsomal suspensions with ferricyanide enhanced ethylmorphine N-demethylase, p-nitroanisole O-demethylase and norbenzphetamine 455-nm complex formation.
    [Abstract] [Full Text] [Related] [New Search]