scholarly journals Role of insulin/glucagon ratio and cell redox state in the hyperglycaemia induced by exposure to a 60-Hz magnetic field in rats

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Gabriel Martiñón-Gutiérrez ◽  
María Luna-Castro ◽  
Rolando Hernández-Muñoz

AbstractThe exposure to extremely low-frequency electromagnetic fields (EMFs) could adversely affect the endocrine system and cellular proliferative response. Nonetheless, the use of 60-Hz EMFs in the form of magneto-therapy exerts beneficial actions on human health but can also induce hyperglycaemia. Therefore, the present study was aimed to search for metabolic responses of fed or fasted male rats to a single EMF exposure. We performed a 15 min-single exposure to 60-Hz (3.8 mT, intensity) EMF, and determined serum levels of glucose, lipids, and indicators of cellular redox state and energy parameters. A single exposure to a 60-Hz EMF induced hyperglycaemia in both animal groups, and an attenuated second serum insulin peak. The 60-Hz EMF also decreased free fatty acids and lactate serum levels, oppositely increasing pyruvate and acetoacetate levels. Significant increases in blood glucose level and rat’s glucose metabolism were related to a more oxidized cellular redox state and variations in insulin and glucagon secretion. The 60-Hz EMF’s effects were not modified in animals previously subjected to chronic EMFs exposure (14 days). In conclusion, increased serum glucose levels and glucose metabolism induced by a single 60-Hz EMF exposure were closely related to the cellular redox state and the insulin/glucagon ratio.

2021 ◽  
Author(s):  
Gabriel Martiñón-Gutiérrez ◽  
María Luna-Castro ◽  
Rolando Hernández-Muñoz

Abstract The exposure to extremely low-frequency electromagnetic fields (EMFs) with a might adversely affect the endocrine system and reproductive functions. Nonetheless, the use of EMFs in the form of magneto-therapy exerts beneficial actions in human medicine, but also affecting glucose and lipids metabolism, inducing hyperglycaemia and a “diabetic” response. Therefore, we used fed or fasted male rats for a single exposure to 60-Hz EMFs, determining serum levels of glucose, lipids, and indicators of cellular redox state and energy parameters. A single exposure to EMFs induced hyperglycaemia in both, fed and fasted rats, accompanied by an attenuated second serum insulin peak. In addition, EMFs also decreased serum levels of free fatty acids and lactate, while they increased those of pyruvate and acetoacetate. Changes in blood glucose level were related with a more oxidized cellular redox state and with the insulin/glucagon ratio. Moreover, rat’s glucose metabolism also coincided with variations in insulin and glucagon secretion, probably depending on cell redox state. The EMFs effects were not modified in animals previously subjected to a chronic exposure (14 days). In conclusion, increased serum glucose levels and glucose metabolism induced by EMFs exposure were closely related with the cellular redox state and with the insulin/glucagon ratio.


2020 ◽  
Author(s):  
Gabriel Martiñón-Gutiérrez ◽  
María Luna-Castro ◽  
Rolando E Hernández-Muñoz

Abstract Background: The exposure to extremely low-frequency electromagnetic fields (EMFs) with a might adversely affect the endocrine system and reproductive functions, as well as the development of animals. Nonetheless, the use of EMFs in the form of magneto-therapy exerts beneficial actions in pain amelioration, post-stroke recovery, or in bone fractures, where EMFs can affect glucose and lipids metabolism, inducing hyperglycemia and a “diabetic” response. Methods: Therefore, we used fed or fasted male rats for a single exposure to 60-Hz EMFs, determining serum levels of glucose, lipids, and indicators of cellular redox state and energy parameter, as well as to perform a metabolic tracing of glucose in the whole animal. Results: A single exposure to EMFs induced hyperglycemia in both, fed and fasted rats, accompanied by an attenuation of a second serum insulin peak. In addition, EMFs also decreased serum levels of free fatty acids and lactate, while they increased those of pyruvate and acetoacetate. Changes in blood glucose level were related with a more oxidized cellular redox state and with the insulin/glucagon ratio. Moreover, rat’s glucose metabolism also coincided with variations in insulin and glucagon secretion, probably depending on cell redox state; these EMFs effects were not modified in animals previously subjected to a chronic exposure (14 days). Conclusions: Increased serum glucose levels and glucose metabolism induced by EMFs exposure were closely related with the cellular redox state and with the insulin/glucagon ratio, whereas changes in the metabolic energy availability seemed to play a minor role in these EMFs-induced metabolic modifications.


2021 ◽  
Vol 22 (2) ◽  
pp. 967
Author(s):  
Maria Favia ◽  
Anna Atlante

The redox states of NAD and NADP are linked to each other in the mitochondria thanks to the enzyme nicotinamide nucleotide transhydrogenase (NNT) which, by utilizing the mitochondrial membrane potential (mΔΨ), catalyzes the transfer of redox potential between these two coenzymes, reducing one at the expense of the oxidation of the other. In order to define NNT reaction direction in CF cells, NNT activity under different redox states of cell has been investigated. Using spectrophotometric and western blotting techniques, the presence, abundance and activity level of NNT were determined. In parallel, the levels of NADPH and NADH as well as of mitochondrial and cellular ROS were also quantified. CF cells showed a 70% increase in protein expression compared to the Wt sample; however, regarding NNT activity, it was surprisingly lower in CF cells than healthy cells (about 30%). The cellular redox state, together with the low mΔΨ, pushes to drive NNT reverse reaction, at the expense of its antioxidant potential, thus consuming NADPH to support NADH production. At the same time, the reduced NNT activity prevents the NADH, produced by the reaction, from causing an explosion of ROS by the damaged respiratory chain, in accordance with the reduced level of mitochondrial ROS in NNT-loss cells. This new information on cellular bioenergetics represents an important building block for further understanding the molecular mechanisms responsible for cellular dysfunction in cystic fibrosis.


2016 ◽  
Vol 100 ◽  
pp. S119 ◽  
Author(s):  
Dustin Carroll ◽  
Yanming Zhao ◽  
Haining Zhu ◽  
Ines Batinic-Haberle ◽  
Daret St. Clair

2020 ◽  
Vol 192 ◽  
pp. 111385 ◽  
Author(s):  
G. Abate ◽  
M. Vezzoli ◽  
M. Sandri ◽  
W. Rungratanawanich ◽  
M. Memo ◽  
...  

2013 ◽  
Vol 37 (5) ◽  
pp. 1130-1143 ◽  
Author(s):  
PANTELIS LIVANOS ◽  
BASIL GALATIS ◽  
CATHERINE GAITANAKI ◽  
PANAGIOTIS APOSTOLAKOS

2019 ◽  
Vol 201 (9) ◽  
Author(s):  
Hui Zhou ◽  
Meizhen Wang ◽  
Nicole E. Smalley ◽  
Maxim Kostylev ◽  
Amy L. Schaefer ◽  
...  

ABSTRACT Pseudomonas aeruginosa uses quorum sensing (QS) to regulate the production of a battery of secreted products. At least some of these products are shared among the population and serve as public goods. When P. aeruginosa is grown on casein as the sole carbon and energy source, the QS-induced extracellular protease elastase is required for growth. We isolated a P. aeruginosa variant, which showed increased production of QS-induced factors after repeated transfers in casein broth. This variant, P. aeruginosa QS*, had a mutation in the glutathione synthesis gene gshA. We describe several experiments that show a gshA coding variant and glutathione affect the QS response. The P. aeruginosa QS transcription factor LasR has a redox-sensitive cysteine (C79). We report that GshA variant cells with a LasR C79S substitution show a similar QS response to that of wild-type P. aeruginosa. Surprisingly, it is not LasR but the QS transcription factor RhlR that is more active in bacteria containing the variant gshA. Our results demonstrate that QS integrates information about cell density and the cellular redox state via glutathione levels. IMPORTANCE Pseudomonas aeruginosa and other bacteria coordinate group behaviors using a chemical communication system called quorum sensing (QS). The QS system of P. aeruginosa is complex, with several regulators and signals. We show that decreased levels of glutathione lead to increased gene activation in P. aeruginosa, which did not occur in a strain carrying the redox-insensitive variant of a transcription factor. The ability of P. aeruginosa QS transcription factors to integrate information about cell density and cellular redox state shows these transcription factors can fine-tune levels of the gene products they control in response to at least two types of signals or cues.


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