Hydrogen peroxide generation by monoamine oxidases in rat white adipocytes: role on cAMP production

In rat, white adipocytes monoamine oxidases (EC 1.4.3.4.) generate hydrogen peroxide (H 2O 2). Recent studies suggested that, in addition to its toxic features, H 2O 2 may behave as a cell second messenger. In the present study, using fluorimetric and chemiluminescence (CL) assays, we showed that ty...

Full description

Saved in:
Bibliographic Details
Published in:European journal of pharmacology 2000-05, Vol.395 (3), p.177-182
Main Authors: Raimondi, Laura, Banchelli, Grazia, Sgromo, Lucia, Pirisino, Renato, Ner, Magalie, Parini, Angelo, Cambon, Claudie
Format: Article
Language:English
Subjects:
Adipocyte
Adipocytes - cytology
Adipocytes - metabolism
Adrenergic beta-Agonists - pharmacology
Animals
Biological and medical sciences
Carbon Radioisotopes
Cell metabolism
Colforsin - pharmacology
Cyclic AMP - metabolism
Dose-Response Relationship, Drug
Fundamental and applied biological sciences. Psychology
Glycerol - metabolism
Hydrogen peroxide
Hydrogen Peroxide - metabolism
Isoproterenol - pharmacology
Male
Monoamine oxidase
Monoamine Oxidase - metabolism
Monoamine Oxidase Inhibitors - pharmacology
Pargyline - pharmacology
Rats
Rats, Wistar
Semicarbazides - pharmacology
Tyramine - metabolism
Tyramine - pharmacology
Vertebrates: skin, associated glands, phaneres, light organs, various exocrine glands (salt gland, uropygial gland...), adipose tissue, connective tissue
white
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:In rat, white adipocytes monoamine oxidases (EC 1.4.3.4.) generate hydrogen peroxide (H 2O 2). Recent studies suggested that, in addition to its toxic features, H 2O 2 may behave as a cell second messenger. In the present study, using fluorimetric and chemiluminescence (CL) assays, we showed that tyramine degradation by monoamine oxidases in intact adipocytes resulted in the concentration-dependent generation of H 2O 2. In addition, we found that, in the presence of low tyramine concentrations, forskolin-dependent cAMP production was significantly increased as compared to that of the control and this increase was prevented by the monoamine oxidase inhibitor pargyline or by the H 2O 2 trapping system homovanillic acid-peroxidase. Finally, we demonstrated that tyramine degradation by monoamine oxidases increased the ability of isoproterenol to induce cell lipolysis. Taken together, these data suggest that H 2O 2 produced during substrate degradation by monoamine oxidases may participate in the regulation of adipocyte metabolism.
ISSN:0014-2999
1879-0712
DOI:10.1016/S0014-2999(00)00181-3