Publication Name	World Journal of Biological Chemistry
Manuscript ID	66383
Country	France

Category	Endocrinology & Metabolism
Manuscript Type	Basic Study
Article Title	Increased monoamine oxidase activity and imidazoline binding sites in insulin-resistant adipocytes from obese Zucker rats
Manuscript Source	Invited Manuscript
All Author List	Christian Carpéné, Luc Marti and Nathalie Morin
Funding Agency and Grant Number	Funding Agency Grant Number Recurrent Grants from Institut National de la Santé et de la Recherche Médicale to the INSERM U1048
Corresponding Author	Christian Carpéné, PhD, Senior Researcher, Institut des Maladies Métaboliques et Cardiovasculaires, INSERM, CHU Rangueil, Bat. L4, BP 84225 , Toulouse 31342, France. christian.carpene@inserm.fr
Key Words	Obesity; Adipocyte; Amine oxidases; Imidazoline binding sites; Creatine kinase B; Idazoxan; Lipogenesis; Hydrogen peroxide; Glucose uptake
Core Tip	The substrates of monoamine oxidase (MAO) and semicarbazide-sensitive amine oxidase (SSAO) partly reproduce the stimulatory effect of insulin on sugar entry in rat fat cells. Especially when combined with vanadium, tyramine and benzylamine mimic more than 70% of the insulin stimulation of glucose uptake. Unfortunately, such insulin activation of glucose utilization is strongly diminished in the genetically obese Zucker rat, an animal model of the metabolic syndrome. In this insulin-resistant and obese rat, the stimulation of glucose transport by tyramine is decreased as much as that of insulin, while the effect of benzylamine is even more altered. SSAO, responsible for benzylamine oxidation, is down-regulated in adipocytes from obese Zucker rats. In contrast, MAO, which predominantly supports the oxidation of tyramine, is increased, apparently not in a sufficient manner to reach the same hexose uptake activation seen in fat cells from lean rats. However, this greater ability to oxidize tyramine was found only in white adipocytes from obese rats since no change was found in the liver or skeletal muscle when compared to lean controls. Moreover, increased MAO activity in the large adipocytes of obese rats was accompanied by an enlarged number of imidazoline binding sites, previously described to be located on MAO. Since the repeated subcutaneous administration of tyramine plus vanadate is somewhat capable of reducing plasma glucose and triglycerides in obese rats, SSAO, MAO, and its associated imidazoline I2 sites deserve further studies with respect to their mimicking insulin action on glucose and lipid metabolism in fat cells.
Citation	Carpéné C, Marti L, Morin N. Increased monoamine oxidase activity and imidazoline binding sites in insulin-resistant adipocytes from obese Zucker rats. World J Biol Chem 2022; 13(1): 15-34

Received	2021-03-26 15:36
Peer-Review Started	2021-03-26 15:40
To Make the First Decision
Return for Revision	2021-07-08 07:17
Revised	2021-07-09 10:38
Second Decision	2022-01-13 05:35
Accepted by Journal Editor-in-Chief
Accepted by Company Editor-in-Chief	2022-01-14 06:34
Articles in Press	2022-01-14 06:34
Publication Fee Transferred
Edit the Manuscript by Language Editor	2021-12-01 02:24
Typeset the Manuscript	2022-01-19 17:20

ISSN	1949-8454 (online)
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