title: Effect of cancer on the in vivo energy state of rat liver and skeletal muscle.
abstract: The effect of increasing tumor burden on host liver and skeletal muscle energy status was studied using P-31 nuclear magnetic resonance spectroscopy (NMR), in rats inoculated with a nonmetastasizing methylcholanthrene-induced sarcoma (TB), and compared to nontumor bearing (NTB) and pair-fed (PF) rats. During the 28-day study, serial measurements of body weight, food intake, and tumor volume were obtained. Using a 0.9-cm double-turn surface coil, weekly NMR measurements were obtained from liver and skeletal muscle. An increasing ratio of [Pi]/[ATP] was used as one measure of intracellular energy depletion. [Pi]/[ATP] in NTB rats remained constant over time at 0.78 +/- 0.10 in liver, and 0.30 +/- 0.10 in skeletal muscle. In TB rats, the [Pi]/[ATP] ratio increased significantly in liver (P = 0.00002) and skeletal muscle (P = 0.04) with increasing tumor burden. In PF rats, no significant change occurred in [Pi]/[ATP] in liver or skeletal muscle, indicating that declining food intake was not responsible for the change in [Pi]/[ATP] seen in TB rats. Surface-coil spectroscopy of liver and skeletal muscle permits serial measurement of visceral energy stores. Increasing tumor burden results in early, ongoing depletion of energy stores as reflected by increasing [Pi]/[ATP] in these organs.
authors.affiliation: Department of Surgery, Victoria Hospital, University of Western Ontario, London, Canada.
authors.forename: A L
authors.initials: AL
authors.lastname: Schneeberger
authors.forename: R T
authors.initials: RT
authors.lastname: Thompson
authors.forename: A A
authors.initials: AA
authors.lastname: Driedger
authors.forename: R J
authors.initials: RJ
authors.lastname: Finley
authors.forename: R I
authors.initials: RI
authors.lastname: Inculet
mesh_terms: D000255:Adenosine Triphosphate / Q000032:analysis; D000818:Animals; D002100:Cachexia / Q000209:etiology; D004734:Energy Metabolism; D006863:Hydrogen-Ion Concentration; D008099:Liver / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D009132:Muscles / Q000378:metabolism*; D009374:Neoplasms, Experimental / Q000378:metabolism*; D010710:Phosphates / Q000032:analysis; D051381:Rats; D011916:Rats, Inbred F344
chemical_list: D010710:Phosphates; D000255:Adenosine Triphosphate