title: Regenerative activity and liver function following partial hepatectomy in the rat using (31)P-MR spectroscopy.
abstract: The aim of the present study was to determine whether alterations in hepatic energy expenditure following partial hepatectomy (PHx), as documented by in vivo hepatic (31)P-MRS, correlate with standard parameters of hepatic regeneration and/or liver function. In addition, we sought to determine whether changes in hepatic energy levels are proportional to the extent of hepatic resection. Adult male Sprague-Dawley rats (4-7 per group) underwent a 40%, 70%, or 90% PHx or sham surgeries. Magnetic resonance spectroscopy (MRS) examinations were performed on each animal 24 or 48 hours thereafter. After MRS examinations, [(3)H]thymidine incorporation into hepatic DNA, proliferating cell nuclear antigen (PCNA) protein expression, and serum bilirubin determinations were performed on each rat. Twenty-four hours following surgery, rats that had undergone 70% PHx had unchanged adenosine triphosphate (ATP) levels but significantly lower ATP/inorganic phosphate (Pi) ratios (P <.05), whereas, at 48 hours post-PHx, both ATP and ATP/Pi levels were lower than in sham- and nonoperated controls (P <.05). Hepatic regeneration and liver dysfunction mirrored these changes; correlations existed between ATP/Pi ratios and [(3)H]thymidine incorporation (r = -0.61, P <.005), PCNA protein expression (r = -0.62, P <.005), and serum bilirubin (r = -0.49, P <.05). For rats that had undergone graded resections, depleted energy levels 48 hours post-PHx were proportional to the extent of resection, degree of enhanced regenerative activity, and liver dysfunction. In conclusion, (31)P-MRS-generated ATP/Pi index is a noninvasive, robust determination that correlates with standard parameters of hepatic regeneration and function.
authors.affiliation: Liver Diseases Unit, Department of Medicine, University of Manitoba, Winnipeg, Canada.
authors.forename: Ian R
authors.initials: IR
authors.lastname: Corbin
authors.forename: Richard
authors.initials: R
authors.lastname: Buist
authors.forename: Vyacheslav
authors.initials: V
authors.lastname: Volotovskyy
authors.forename: Jim
authors.initials: J
authors.lastname: Peeling
authors.forename: Manna
authors.initials: M
authors.lastname: Zhang
authors.forename: Gerald Y
authors.initials: GY
authors.lastname: Minuk
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D004734:Energy Metabolism / Q000502:physiology*; D006498:Hepatectomy; D008099:Liver / Q000378:metabolism* / Q000601:surgery; D008115:Liver Regeneration / Q000502:physiology*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D010759:Phosphorus Isotopes; D051381:Rats; D017207:Rats, Sprague-Dawley; D013936:Thymidine / Q000493:pharmacokinetics; D014316:Tritium
chemical_list: D010759:Phosphorus Isotopes; D014316:Tritium; D000255:Adenosine Triphosphate; D013936:Thymidine