Implication of rifampicin-quinone in the irreversible binding of rifampicin to macromolecules

1. When [3H]rifampicin is incubated with rat liver microsomes or rat liver homogenate, minor amounts are bound irreversibly to protein. This effect does not depend on the presence of NAD, NADH, NADP or NADPH. 2. Rifampicin is autoxidized at physiological pH. The product of autoxidation, rifampicin-quinone, if incubated with albumin, shows a much greater irreversible binding to the protein than the parent compound rifampicin. Hence it is concluded that rifampicin may bind irreversibly to proteins in a non-enzymic reaction after autoxidation to rifampicin-quinone. 3. Rifampicin-quinone also binds irreversibly to RNA and poly-L-lysine, if incubated with these compounds. This suggests that free amino groups of protein or RNA are involved in the binding. 4. 48 h after dosage of [3H]rifampicin (33 mg/kg) to rats, 29-2 +/- 4-1 (S.D.) pmol are bound irreversibly to 1 mg liver RNA, 15.8 +/- 8-1 pmol to 1 mg liver protein and 5-0 +/- 0-47 pmol to 1 mg protein in brain tissue. 5. Microsomal NADPH-cytochromcin-quinone to rifampicin. The KM of this reaction is 10(-4) M. Induction of the NADPH-cytochrome c reductase by pre-treatment of rats with 20 mg/kg rifampicin over 5 days results in a corresponding increase of increase of rifampicin-quinone reduction. 6. These results suggest that microsomal NADPH-cytochrome c reductase prevents accumulation of higher amounts of possibly toxic rifampicin-quinone by reduction to rifampicin.

Medienart:

Artikel

Erscheinungsjahr:

1976

Erschienen:

1976

Enthalten in:

Zur Gesamtaufnahme - volume:6

Enthalten in:

Xenobiotica; the fate of foreign compounds in biological systems - 6(1976), 1 vom: 28. Jan., Seite 21-32

Sprache:

Englisch

Beteiligte Personen:

Bolt, H M [VerfasserIn]
Remmer, H [VerfasserIn]

Themen:

0U46U6E8UK
53-59-8
63231-63-0
9007-49-2
DNA
EC 1.6.2.4
Journal Article
Macromolecular Substances
NAD
NADP
NADPH-Ferrihemoprotein Reductase
Proteins
Quinones
RNA
Receptors, Drug
Rifampin
VJT6J7R4TR

Anmerkungen:

Date Completed 02.08.1976

Date Revised 12.01.2022

published: Print

Citation Status MEDLINE

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM000064750