The effect of insulin on the intracellular distribution of 14(R,S)-[18F]Fluoro-6-thia-heptadecanoic acid in rats.
OBJECTIVE
The aim of this study was to determine the effect of hyperinsulinemia on myocardial and hepatic distribution and metabolism of 14(R,S)-[18F]fluoro-6-thia-heptadecanoic acid ([18F]FTHA).


METHODS
Mitochondrial retention and intracellular lipid incorporation of [18F]FTHA were compared to that of [14C]-2-bromopalmitate or [14C]palmitate during hyperinsulinemic clamp vs. saline infusion in male Wistar rats.


RESULTS
Mitochondrial 18F activity was increased in the heart (1.7 +/- 0.4 vs. 0.5 +/- 0.1% ID/g, P < 0.05), whereas it was reduced in the liver (1.1 +/- 0.3 vs. 1.8 +/- 0.4% ID/g, P < 0.05) during insulin vs. saline infusion, respectively. Mitochondrial [14C]-2-bromopalmitate activity was affected by insulin in a similar way in both tissues. The fractional esterification of [18F]FTHA into triglycerides was impaired compared to [14C]palmitate in both tissues, and [18F]FTHA was insensitive to the shift of esterification of fatty acids into complex lipids in response to insulin.


CONCLUSIONS
[18F]FTHA is sensitive to insulin-induced modifications of free fatty acid oxidative metabolism in rats but is insensitive to changes in nonoxidative fatty acid metabolism.
Ci
Xiuli
X
Department of Medicine, Division of Endocrinology, Centre hospitalier universitaire de Sherbrooke, Université de Sherbrooke, Sherbrooke, Québec, Canada.
Frisch
Frédérique
F
Lavoie
François
F
Germain
Pascale
P
Lecomte
Roger
R
van Lier
Johan E
JE
Bénard
François
F
Carpentier
André C
AC
D000818:Animals; D001682:Biological Availability; D001786:Blood Glucose / Q000032:analysis; D005227:Fatty Acids / Q000493:pharmacokinetics*; D006946:Hyperinsulinism / Q000378:metabolism; D007328:Insulin / Q000097:blood / Q000494:pharmacology*; D050356:Lipid Metabolism / Q000187:drug effects; D008099:Liver / Q000378:metabolism*; D008297:Male; D008929:Mitochondria, Heart / Q000378:metabolism; D008930:Mitochondria, Liver / Q000378:metabolism; D009206:Myocardium / Q000378:metabolism*; D010168:Palmitates; D051381:Rats; D017208:Rats, Wistar; D014018:Tissue Distribution; D014916:Whole-Body Irradiation
D001786:Blood Glucose; D005227:Fatty Acids; D007328:Insulin; D010168:Palmitates; C071178:14-fluoro-6-thiaheptadecanoic acid; C022776:2-bromopalmitate