Clustering of cardiovascular risk factors mimicking the human metabolic syndrome X in eNOS null mice.
Level 5 - mechanism / opinion, no new human data
Controlled animal experiment with no human data
PubMed 12947532 · doi:10.4414/smw.2003.10239
What was done
Researchers evaluated 10- to 12-week-old endothelial nitric oxide synthase knockout (eNOS-/-) mice and wild-type control mice. They measured arterial pressure, insulin sensitivity using euglycaemic hyperinsulinaemic clamps, and plasma concentrations of insulin, leptin, cholesterol, triglycerides, free fatty acids, fibrinogen, and uric acid. Glucose tolerance was assessed under basal conditions and following a high-fat diet challenge.
What was found
Compared to wild-type controls, eNOS-/- mice were hypertensive and insulin resistant, showing fasting hyperinsulinaemia and an approximately 30% lower steady-state glucose infusion rate during clamp studies. eNOS-/- mice had a 1.5- to 2-fold elevation in plasma cholesterol, triglycerides, and free fatty acids. Despite comparable body weights, plasma leptin was 30% higher in eNOS-/- mice, with elevated uric acid and fibrinogen. Basal glucose tolerance was comparable between groups, but eNOS-/- mice developed significantly worse glucose intolerance following a high-fat diet. Absolute baseline values and exact sample sizes were not reported in the abstract.
Why it matters
This study demonstrates that a single gene deletion in eNOS can recapitulate the multifaceted cluster of human metabolic syndrome X in mice, highlighting a potential causal role for impaired nitric oxide synthesis in metabolic dysfunction.
Limits
This was an animal study; findings may not fully generalize to human pathophysiology. The abstract does not report the total sample size (n), exact numerical blood pressures, absolute lipid concentrations, or measures of variance (e.g., standard deviations or p-values).
Cited by
- supports Endothelial nitric oxide synthase (eNOS) knockout mice spontaneously develop features of the metabolic syndrome.