Mitochondria found to run as high as 50 C

May 10, 2017 by Bob Yirka, Medical Xpress report
Mitochondria. Credit: Wikipedia commons

(Phys.org)—A team of researchers with members from France, Korea and Germany has found that temperatures inside human mitochondria can run as high as 50°C. In their paper uploaded to the preprint server bioRxiv, the group describes how they used temperature-sensitive dyes to determine the temperature of the organelles and what their findings might mean for prior biological research that has relied on lower temperatures during reactions.

The healthy human is supposed to maintain a constant of 37°C, but now it appears our cells may actually run much hotter. In this new effort, the researchers took the temperature of mitochondria in skin, kidney and , and found them to be much hotter than was anticipated.

Because it is impossible with existing technology to take the temperature of mitochondria using conventional thermometers, the team took a new approach, applying a type of dye that changes color depending on the temperature of its environment. The dye, called Mito-Thermo-Yellow, binds to targets, and loses fluorescence as the temperature around it rises. When applied to the mitochondria, the team found that it could be used to accurately measure its temperature while still inside the cell.

Mitochondria are, of course, organelles that exist inside cells and serve the purpose of converting oxygen and other food into energy for the body to use as a power source. They do so by using oxygen to burn the food that we eat, leading to the creation of ATP—thus, it is not surprising that such cellular respiration results in the generation of heat—what is surprising, the researchers note, is how much.

The work comes on the heels of work done by a team in Japan that used a to determine the temperature of inside of cancer —they found temperatures there to be 6 to 9°C higher than normal body temperature.

Many in the media have noted that if the findings by this team prove reproducible by others, it could have a big impact on cellular research because many findings have been based on how quickly reactions occur inside the body at or near normal body temperatures.

Explore further: Study shows memory loss due to cannabis related to harm to mitochondria

More information: Mitochondria Are Physiologically Maintained At Close To 50 C, Dominique Chretien et al. biorxiv.org/content/early/2017/05/02/133223

Abstract
In warm-blooded species, heat released as a by-product of metabolism ensures stable internal temperature throughout the organism, despite varying environmental conditions. Mitochondria are major actors in this thermogenic process. The energy released by the oxidation of respiratory substrates drives ATP synthesis and metabolite transport, with a variable proportion released as heat. Using a temperature-sensitive fluorescent probe targeted to mitochondria, we measured mitochondrial temperature in situ under different physiological conditions. At a constant external temperature of 38 C, mitochondria were more than 10 C warmer when the respiratory chain was fully functional, both in HEK cells and primary skin fibroblasts. This differential was abolished by respiratory inhibitors or in cells lacking mitochondrial DNA, but enhanced by expressing thermogenic enzymes such as the alternative oxidase or the uncoupling protein UCP1. The activity of various RC enzymes was maximal at, or slightly above, 50 C. Our study prompts a re-examination of the literature on mitochondria, taking account of the inferred high temperature.

Related Stories

Study shows memory loss due to cannabis related to harm to mitochondria

November 10, 2016
(Medical Xpress)—An international team of researchers has found what they believe is the source of memory loss in people who smoke marijuana—disruption to mitochondria. In their paper published in the journal Nature, ...

Noninvasive microscopy technique allows for spotting skin cancer in mitochondria

December 1, 2016
(Medical Xpress)—A team of researchers from several institutions in the U.S. and one in Spain has developed a new way to test for skin cancer in patients—one that does not rely on taking a biopsy. In their paper published ...

Recommended for you

Fabric imbued with optical fibers helps fight skin diseases

February 23, 2018
A team of researchers with Texinov Medical Textiles in France has announced that their PHOS-ISTOS system, called the Fluxmedicare, is on track to be made commercially available later this year. The system consists of a piece ...

Low-calorie diet enhances intestinal regeneration after injury

February 22, 2018
Dramatic calorie restriction, diets reduced by 40 percent of a normal calorie total, have long been known to extend health span, the duration of disease-free aging, in animal studies, and even to extend life span in most ...

Artificial intelligence quickly and accurately diagnoses eye diseases and pneumonia

February 22, 2018
Using artificial intelligence and machine learning techniques, researchers at Shiley Eye Institute at UC San Diego Health and University of California San Diego School of Medicine, with colleagues in China, Germany and Texas, ...

Gut microbes protect against sepsis—mouse study

February 22, 2018
Sepsis occurs when the body's response to the spread of bacteria or toxins to the bloodstream damages tissues and organs. The fight against sepsis could get a helping hand from a surprising source: gut bacteria. Researchers ...

Breakthrough could lead to better drugs to tackle diabetes and obesity

February 22, 2018
Breakthrough research at Monash University has shown how different areas of major diabetes and obesity drug targets can be 'activated', guiding future drug development and better treatment of diseases.

Fertility breakthrough: New research could extend egg health with age

February 22, 2018
Women have been told for years that if they don't have children before their mid-30s, they may not be able to. But a new study from Princeton University's Coleen Murphy has identified a drug that extends egg viability in ...

2 comments

Adjust slider to filter visible comments by rank

Display comments: newest first

EarthlingToo
not rated yet May 10, 2017
Bigger picture: this study highlights one of the most important reasons we should be drinking plenty of water. In addition to the many benefits to digestion, cardiovascular performance, cell volume, and filtration of all major bodily systems, water is a necessary coolant (inside and out). All metabolic reactions involve giving off heat, and what better way to cool a system down than through constant circulation of a fluid that absorbs and dissipates heat?

If this carefully calibrated system runs amok and body temps rise or fall by more than a couple degrees, one experiences either hyperthermia (fever) or hypothermia (both of which can be fatal).
vacuumforce
May 10, 2017
This comment has been removed by a moderator.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.