title: Use of 1H/23Na and 1H/31P double frequency tuned birdcage coils to study in vivo carbon tetrachloride-induced hepatotoxicity in rats.
abstract: In vivo 1H and 23Na magnetic resonance imaging (MRI) and 31P magnetic resonance spectroscopy (MRS) techniques were used to study CCl4-induced acute hepatotoxicity in rats in situ. One or two hours following exposure to CCl4, a localized edematous region was detected in the liver by 1H MRI. The CCl4-induced edema was localized in a region surrounding the hepatic portal vein. With the use of a 23Na/1H double frequency tuned bird-cage imaging coil an increase in Na+ ion flux was also observed in the same region as the edematous region detected by 1H-MRI. Pretreatment with alpha-phenyl-tert-butyl nitrone (PBN), a free radical spin trap, 30 min prior to CCl4 exposure, was found to reduce the CCl4-induced edematous response in the liver observed in either 1H or 23Na-NMR images. Inhibition of the CCl4-induced edematous response in rat liver by PBN demonstrates that free radical intermediates, arising from the metabolism of CCl4, are possibly the key causal agents in the initiation of the edematous response. In addition, with the use of a 31P/1H double frequency tuned bird-cage imaging/spectroscopy coil, localized 31P spectra (ISIS) were obtained from the regions of CCl4-induced "tissue damage" observed in the 1H-MRI images. The most notable changes observed from the 31P spectra were an increase in inorganic phosphate (Pi) and a decrease in hepatocytosolic pH in the CCl4-treated rat livers in comparison to saline-treated control livers.
authors.affiliation: MRI Facility, Ontario Veterinary College, University of Guelph, Canada.
authors.forename: R A
authors.initials: RA
authors.lastname: Towner
authors.forename: E G
authors.initials: EG
authors.lastname: Janzen
authors.forename: S C
authors.initials: SC
authors.lastname: Chu
authors.forename: A
authors.initials: A
authors.lastname: Rath
mesh_terms: D000818:Animals; D002252:Carbon Tetrachloride Poisoning / Q000175:diagnosis*; D056486:Chemical and Drug Induced Liver Injury / Q000175:diagnosis*; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods*; D009682:Magnetic Resonance Spectroscopy / Q000295:instrumentation / Q000379:methods*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains