Arecoline-stimulated brain incorporation of intravenously administered fatty acids in unanesthetized rats.
Brain incorporation of [1-14C]arachidonate ([14C]AA; 170 microCi/kg), [1-14C]docosahexaenoate ([14C]DA; 100 microCi/kg), or [9,10-3H]palmitate ([3H]PA; 6.4 mCi/kg) infused intravenously for 5 min was examined in the awake rat following systemic administration of the cholinomimetic arecoline (15 mg/kg i.p.). The rat was killed 15 min after infusion, and the brain was removed, frozen, and prepared for biochemical analysis and autoradiography. Brain radioactivity, normalized for plasma exposure, was increased by 41 and 45% in arecoline-treated rats given [14C]AA and [14C]DA, respectively. Pretreatment with atropine prevented the increase in fatty acid incorporation. Arecoline treatment had no effect on brain incorporation of [3H]PA. Quantitative autoradiography indicated regionally selective increases in brain [14C]AA and [14C]DA incorporation in response to arecoline. The results suggest that intravenously administered radiolabeled fatty acids can be used to study neurotransmitter-stimulated brain lipid metabolism in vivo.
DeGeorge
J J
JJ
Laboratory of Neurosciences, National Institute on Aging, National Institutes of Health, Bethesda, Maryland 20892.
Nariai
T
T
Yamazaki
S
S
Williams
W M
WM
Rapoport
S I
SI
D000818:Animals; D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000008:administration & dosage / Q000378:metabolism; D001115:Arecoline / Q000494:pharmacology*; D001285:Atropine / Q000494:pharmacology; D001345:Autoradiography; D001921:Brain / Q000187:drug effects / Q000378:metabolism*; D002250:Carbon Radioisotopes; D004281:Docosahexaenoic Acids / Q000008:administration & dosage / Q000378:metabolism; D005227:Fatty Acids / Q000008:administration & dosage / Q000378:metabolism*; D007262:Infusions, Intravenous; D008297:Male; D019308:Palmitic Acid; D010169:Palmitic Acids / Q000008:administration & dosage / Q000378:metabolism; D051381:Rats; D011916:Rats, Inbred F344
D001095:Arachidonic Acids; D002250:Carbon Radioisotopes; D005227:Fatty Acids; D010169:Palmitic Acids; D004281:Docosahexaenoic Acids; D016718:Arachidonic Acid; D019308:Palmitic Acid; D001115:Arecoline; D001285:Atropine