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Updated: Jan 4, 2026
Measuring the Rate of Lipolysis in Ex Vivo Murine Adipose Tissue and Primary Preadipocytes Differentiated In Vitro
Published on: March 17, 2023
Methylglyoxal impairs β-adrenergic signalling in primary rat adipocytes
Tomasz Szkudelski1, Aleksandra Cieślewicz1, Katarzyna Szkudelska1
1Department of Animal Physiology and Biochemistry, Poznan University of Life Sciences, Poznan, Poland.
Abstract:
Methylglyoxal (MG) is dicarbonyl aldehyde generated intracellularly from glucose and from some other compounds. Its increased formation is associated with several harmful consequences. In the present study, short-term effects of MG on metabolism of isolated rat adipocytes were determined. Insulin-induced lipogenesis was unchanged by MG. However, epinephrine-stimulated lipolysis was shown to be significantly reduced in adipocytes exposed to 200 µM MG. This inhibitory effect was similar in the presence of low and high concentrations of glucose, and also in the presence of alanine. However, MG failed to affect lipolysis induced by forskolin (activator of adenylate cyclase), dibutyryl-cAMP (activator of PKA) and DPCPX (adenosine A1 receptor antagonist). It was also revealed that lipolysis was unchanged by MG in fat cells pre-incubated with this compound, and then stimulated with epinephrine alone. Our results suggest that MG may impair β-adrenergic signalling in rat adipocytes due to interaction with epinephrine, and thereby disturbs lipolysis.
Insights
Methylglyoxal (MG) impairs fat breakdown (lipolysis) in rat fat cells by interfering with epinephrine signaling. This finding suggests a novel mechanism linking MG to metabolic dysfunction.
Area of Science:
- Metabolic biochemistry
- Cellular metabolism
- Endocrinology
Background:
- Methylglyoxal (MG) is a reactive dicarbonyl compound formed from glucose metabolism.
- Elevated MG levels are linked to various pathological conditions.
- Understanding MG's cellular effects is crucial for metabolic disease research.
Purpose of the Study:
- To investigate the short-term metabolic effects of methylglyoxal (MG) on isolated rat adipocytes.
- To determine MG's impact on insulin-stimulated lipogenesis and epinephrine-stimulated lipolysis.
- To elucidate the signaling pathways affected by MG in adipocytes.
Main Methods:
- Isolated rat adipocytes were treated with varying concentrations of methylglyoxal (MG).
- Lipogenesis was assessed by measuring insulin-induced lipid synthesis.
- Lipolysis was measured by quantifying glycerol release following stimulation with epinephrine or other signaling agents.
- Specific signaling pathway activators (forskolin, dibutyryl-cAMP) and receptor antagonists were used.
Main Results:
- Methylglyoxal (MG) did not alter insulin-induced lipogenesis.
- Epinephrine-stimulated lipolysis was significantly inhibited by MG (200 µM) in adipocytes.
- MG's inhibitory effect on lipolysis was independent of glucose or alanine presence.
- MG did not affect lipolysis induced by forskolin, dibutyryl-cAMP, or DPCPX, indicating the effect is upstream of adenylate cyclase and PKA.
- Pre-incubation with MG followed by epinephrine stimulation also showed unchanged lipolysis, suggesting a direct interaction with epinephrine or its receptor.
Conclusions:
- Methylglyoxal (MG) significantly impairs epinephrine-stimulated lipolysis in rat adipocytes.
- The data suggest MG interferes with beta-adrenergic signaling, potentially by interacting with epinephrine itself.
- These findings highlight a novel mechanism by which MG may disrupt adipocyte function and contribute to metabolic disturbances.
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