When rat hearts were given lactate, the proteins that bring glucose into heart cells moved to the cell surface in larger numbers. This shows lactate can increase the heart's ability to take up glucose.
See the scientific wording
In isolated perfused rat hearts, exposure to 10 mM lactate increases the plasma membrane translocation of both GLUT1 and GLUT4 glucose transporters.
Correlational — new studies may shift this
ObservationalOne low-scoring study links this claim to the outcome, but causation is not established.
What the research says
1 study reviewedSupporting (1)
Cross-Sectional StudyAnimal2002
The study found that giving lactate to rat hearts does increase the number of sugar transporters on the cell surface, just like the claim says, even though it also found that the hearts actually stored less sugar.
Contradicting (0)
No contradicting studies found yet
That doesn't mean it's settled — it just means no study has tested the opposite.
Quality-weighted scoring: we follow the GRADE framework — each study is rated High, Moderate, Low, or Very Low based on study design, methodology rigor, and risk of bias. A single high-quality RCT can outweigh several weaker observational studies.
Scores reflect study quality, not just count.
Lactate makes heart cells move their sugar transporters (GLUT1 and GLUT4) from inside the cell to the outside surface. This happens without using a common cell signaling pathway called PI3K. Even though more transporters are on the surface, the cells actually store less sugar because the step that attaches a phosphate to sugar is slowed down. So, the cells have more doors for sugar, but the sugar doesn't get in or get used as well.
Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting study
How Fit Body Science checks a claim
- 1
We isolate the claim
Health advice from videos, articles and studies is broken down into single, testable claims.
- 2
We find the research
Each claim is matched against peer-reviewed studies, with every source cited by DOI.
- 3
We grade the evidence
Studies are scored on methodology, statistical rigor, transparency and publication quality.
The fitness and health internet is full of confident claims. We check them against real research.
Every claim on this site is traced back to peer-reviewed studies, scored on methodology and reporting quality, and given a verdict you can audit yourself — sources, DOIs and all.
- Full evidence breakdown and mechanism chains
- Ask our AI anything about a claim or its studies
- Get notified when new research changes a verdict
When rat hearts were given lactate, the proteins that bring glucose into heart cells moved to the cell surface in larger numbers. This shows lactate can increase the heart's ability to take up glucose.
Mechanism
1 studyLactate tells heart cells to move their sugar transporters to the outside. Even though there are more transporters on the surface, the cells still take in less sugar because the step that attaches a phosphate to sugar is slowed down. So the cells have more doors but the sugar can't get in as well.
Lactate makes heart cells move their sugar transporters (GLUT1 and GLUT4) from inside the cell to the outside surface. This happens without using a common cell signaling pathway called PI3K. Even though more transporters are on the surface, the cells actually store less sugar because the step that attaches a phosphate to sugar is slowed down. So, the cells have more doors for sugar, but the sugar doesn't get in or get used as well.
Lactate interacts with cardiac myocytes, activating an intracellular signaling cascade.
This signaling cascade promotes the trafficking and fusion of GLUT1- and GLUT4-containing vesicles with the plasma membrane, increasing the number of glucose transporters on the cell surface.
The translocation occurs independently of the PI3K pathway, as pharmacological inhibition of PI3K does not prevent the increase in surface GLUT1 and GLUT4.
Despite the increased surface density of glucose transporters, the phosphorylation and cellular accumulation of glucose analogues is markedly reduced, indicating that the increased transporter availability does not lead to increased glucose uptake, possibly due to inhibition of hexokinase activity or another downstream regulatory step.
Evidence from Studies
Supporting (1)
Community contributions welcome
Lactate-induced translocation of GLUT1 and GLUT4 is not mediated by the phosphatidylinositol-3-kinase pathway in the rat heart
The study found that giving lactate to rat hearts does increase the number of sugar transporters on the cell surface, just like the claim says, even though it also found that the hearts actually stored less sugar.
Contradicting (0)
Community contributions welcome
Score Breakdown
No multi-axis breakdown available yet. The overall Pro / Against score above is the best signal.
- No clinical evidence is available; the score reflects mechanistic plausibility only.
What Would Prove This
Per GRADE and EBM methodology, here is what ideal scientific evidence would look like to definitively prove or disprove this claim, ordered from strongest to weakest.
Systematic Review and Meta-Analysis of Studies on Lactate-Induced GLUT Translocation in Cardiac Tissue
Comprehensive search of databases (PubMed, Embase, etc.) for all studies, animal or cell-based, that measure GLUT1/GLUT4 translocation in cardiac tissue after lactate exposure. Include quantitative synthesis if possible.
Randomized Controlled Trial of Lactate Infusion vs Placebo on Myocardial GLUT Translocation in a Rat Model
Randomize isolated perfused rat hearts to receive 10 mM lactate or control buffer for a set period. Measure plasma membrane GLUT1/GLUT4 via Western blot or immunofluorescence. Include multiple replicates and blinding if possible.
Prospective Cohort Study on Blood Lactate Levels and Myocardial Glucose Uptake in Patients with Cardiac Conditions
Follow a cohort of patients with or without elevated lactate (e.g., during exercise, critical illness) and measure myocardial glucose uptake via PET or biopsy. Correlate lactate levels with GLUT expression.
Case-Control Study Comparing Cardiac GLUT1/GLUT4 Expression in Patients with Lactic Acidosis vs Controls
Select cases (e.g., patients with lactic acidosis) and matched controls. Obtain cardiac tissue samples (e.g., from biopsy or surgery) and measure GLUT1/GLUT4 membrane localization.
In Vitro Study of Cardiomyocytes Exposed to 10 mM Lactate to Measure GLUT1 and GLUT4 Translocation
Culture cardiomyocytes (e.g., H9c2 cells or primary rat cardiomyocytes) and treat with 10 mM lactate for varying durations. Assess GLUT1/GLUT4 plasma membrane levels by cell surface biotinylation or immunofluorescence.