Why poking a mouse’s tail messes up its blood test
Impact of acute stress on murine metabolomics and metabolic flux
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
When scientists take blood from a mouse’s tail, the mouse gets scared, and its muscles pump out lots of lactate and pyruvate — like a sprinter’s legs burning. This makes the blood look weird, even if nothing’s wrong with the mouse. The best way to get real data is to take blood from a tiny tube already in its artery, without scaring it.
Surprising Findings
Lactate is the primary carbon source feeding the TCA cycle in fasted mice, not glucose.
Textbooks teach that glucose is the main fuel for cellular respiration. This study shows that even without food, lactate—often seen as a byproduct—is the real driver, challenging decades of metabolic dogma.
Practical Takeaways
If you’re designing a mouse study measuring metabolism, use arterial catheters instead of tail snips—even if it’s harder or more expensive.
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
When scientists take blood from a mouse’s tail, the mouse gets scared, and its muscles pump out lots of lactate and pyruvate — like a sprinter’s legs burning. This makes the blood look weird, even if nothing’s wrong with the mouse. The best way to get real data is to take blood from a tiny tube already in its artery, without scaring it.
Surprising Findings
Lactate is the primary carbon source feeding the TCA cycle in fasted mice, not glucose.
Textbooks teach that glucose is the main fuel for cellular respiration. This study shows that even without food, lactate—often seen as a byproduct—is the real driver, challenging decades of metabolic dogma.
Practical Takeaways
If you’re designing a mouse study measuring metabolism, use arterial catheters instead of tail snips—even if it’s harder or more expensive.
Publication
Journal
Proceedings of the National Academy of Sciences of the United States of America
Year
2023
Authors
W. Lee, Lingfan Liang, Jenna E. AbuSalim, Connor S. R. Jankowski, Laith Z. Samarah, Michael D. Neinast, Joshua D. Rabinowitz
Related Content
Claims (7)
When you're under sudden stress, your liver quickly makes more sugar and releases it into your blood so your muscles have extra energy to react.
Using a tiny tube in a mouse’s artery to measure blood flow is more reliable than cutting its tail, because tail cutting stresses the mouse and gives wrong numbers.
When mice haven't eaten, their blood has more lactate than any other fuel molecule—even more than sugar—and their body uses this lactate as the main fuel to power their cells, even when they're not stressed or in danger.
Cutting a small piece off an animal’s tail releases chemicals from the damaged tissue, which messes up the blood test results by making it look like there are more of these chemicals in the body than there really are.
When mice are suddenly handled and stressed, their bodies quickly make certain energy fuels—like lactate and fatty acids—because their fight-or-flight system kicks in. This claim says that giving mice the same stress hormones (epinephrine and norepinephrine) makes them produce those same fuels just as fast, proving it’s the hormones, not the stress itself, doing the work.