A model for research on the blood-brain barrier disruption induced by unsaturated fatty acid emulsion.
OBJECTIVE
The authors investigated whether fatty acid emulsion affects the blood-brain barrier (BBB), whether disrupted BBB is reversible, and whether the fatty acid emulsion technique may be a model for BBB research.


METHODS
The fat emulsion was made with 0.05 mL of oleic acid or linoleic acid and 20 mL of normal saline. The internal carotid artery in 14 cats was infused with oleic acid emulsion (group 1) and with linoleic acid emulsion in 12 cats (group 2). Gd-enhanced T1-weighted (Gd-T1WI), diffusion-weighted (DWI), and additional apparent diffusion coefficient (ADC) map magnetic resonance imaging (MRI) was obtained at 1 hour, 1 and 4 days, and 1 week after infusion. MRI findings were evaluated qualitatively. Quantitatively, the signal intensity ratio (SIR) of the lesion to the contralateral hemisphere was measured on Gd-T1WIs. The SIRs were statistically analyzed using the student t test. The brain tissue was removed immediately for light and electron microscopy examination if the lesion showed no contrast enhancement and was isointense on DWIs and the ADC maps.


RESULTS
The lesions appeared at 1 hour in both groups as contrast enhancement on Gd-T1WIs, as isointensity or mild hyperintensity on DWIs, and as isointensity on the ADC maps. On day 1, these MRI findings were decreased in group 1 and were not seen in group 2. At 1 hour, the SIRs of group 1 were significantly higher than those of group 2 (P = 0.016). On day 1, the SIRs of both groups approximated 1.0. Light microscopy findings revealed minor necrosis and demyelination in one cat from group 1 and in 3 cats from group 2. Electron microscopy examinations showed minimal findings in the cortical lesions in groups 1 and 2.


CONCLUSIONS
Infusion of unsaturated fatty acid emulsion into the carotid artery of cats revealed vasogenic edema of the brain and reversible changes as depicted on MRI. This unsaturated fat emulsion technique may be used as a model for research on BBB disruption.
Kim
Hak Jin
HJ
Department of Radiology, Pusan National University College of Medicine, Pusan, South Korea. hakjink@pusan.ac.kr
Pyeun
Yong Seon
YS
Kim
Yong Woo
YW
Cho
Byung Mann
BM
Lee
Tae Hong
TH
Moon
Tae Yong
TY
Suh
Kuen Tak
KT
Park
Byung-Rae
BR
D000818:Animals; D001812:Blood-Brain Barrier / Q000187:drug effects*; D001921:Brain / Q000187:drug effects / Q000473:pathology; D001929:Brain Edema / Q000139:chemically induced / Q000473:pathology; D002343:Carotid Artery, Internal; D002415:Cats; D003711:Demyelinating Diseases / Q000139:chemically induced / Q000473:pathology; D038524:Diffusion Magnetic Resonance Imaging; D004195:Disease Models, Animal; D004655:Emulsions; D019786:Gadolinium DTPA; D007089:Image Enhancement / Q000379:methods; D007269:Injections, Intra-Arterial; D019787:Linoleic Acid / Q000008:administration & dosage / Q000494:pharmacology*; D009336:Necrosis; D019301:Oleic Acid / Q000008:administration & dosage / Q000494:pharmacology*; D013997:Time Factors
D004655:Emulsions; D019301:Oleic Acid; D019787:Linoleic Acid; D019786:Gadolinium DTPA