The effects of insulin on plasma mevalonate concentrations in man.
Mevalonate production is a limiting step in cholesterol synthesis. We studied the effects of insulin on plasma mevalonate concentrations during a 3-hour euglycemic hyperinsulinemic clamp study in 10 healthy males starting at 9 h a.m. after 14 h of fasting. Physiological variations in plasma mevalonate were evaluated on a different day from 9 to 12 h a.m. under saline infusion. During the clamp studies, slight but significant decreases were noted for VLDL-triglyceride and VLDL-cholesterol at 120 and 180 min (p < 0.05) and for apolipoprotein B-100 from 60 min on (p < 0.05). Plasma mevalonate decreased significantly by 34 and 41% at 120 and 180 min, respectively (p < 0.001), while the mean percent decrease due to diurnal variations was 12% at 12 h a.m. In conclusion, hyperinsulinemia in the presence of euglycemia acutely decreases the circulating levels of mevalonic acid, the immediate product of HMG CoA reductase in the cholesterol pathway.
Lala
A
A
Department of Internal Medicine, University of Rome Tor Vergata, Italy.
Scoppola
A
A
Ricci
A
A
Frontoni
S
S
Gambardella
S
S
Menzinger
G
G
D000328:Adult; D001055:Apolipoproteins B / Q000097:blood; D002784:Cholesterol / Q000378:metabolism; D015243:Cholesterol, VLDL / Q000097:blood; D002940:Circadian Rhythm / Q000502:physiology; D005215:Fasting / Q000097:blood / Q000502:physiology; D015309:Glucose Clamp Technique; D006801:Humans; D006946:Hyperinsulinism / Q000097:blood; D007262:Infusions, Intravenous; D007328:Insulin / Q000008:administration & dosage / Q000494:pharmacology*; D008297:Male; D008798:Mevalonic Acid / Q000097:blood*; D013997:Time Factors; D014280:Triglycerides / Q000097:blood
D001055:Apolipoproteins B; D015243:Cholesterol, VLDL; D007328:Insulin; D014280:Triglycerides; D002784:Cholesterol; D008798:Mevalonic Acid