In the fat around the heart and blood vessels of heart failure patients, the MAO-A enzyme is much more common than the MAO-B enzyme.
Scientific Claim
Monoamine oxidase A (MAO-A) is the predominant isoform expressed in human epicardial and perivascular adipose tissue from patients with heart failure, as determined by higher protein expression levels compared to MAO-B using immunofluorescence.
Original Statement
“Our data showed that both MAO isoforms are present in human EAT and PVAT, with a higher expression in the former as compared to the latter (by analyzing the IF intensity). However, the protein expression of MAO-A isoform was significantly higher.”
Evidence Quality Assessment
Claim Status
appropriately stated
Study Design Support
Design supports claim
Appropriate Language Strength
definitive
Can make definitive causal claims
Assessment Explanation
The claim is a direct description of observed protein expression levels in the tissue samples. No causal inference is made, and the language accurately reflects the descriptive nature of the measurement.
Evidence from Studies
Supporting (1)
Methylene blue reduces monoamine oxidase expression and oxidative stress in human cardiovascular adipose tissue
Scientists found that in fat around the hearts of heart failure patients, a protein called MAO-A is much more common than MAO-B, and it helps create harmful stress in the tissue.