Effect of cancer on the in vivo energy state of rat liver and skeletal muscle.
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.
Schneeberger
A L
AL
Department of Surgery, Victoria Hospital, University of Western Ontario, London, Canada.
Thompson
R T
RT
Driedger
A A
AA
Finley
R J
RJ
Inculet
R I
RI
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
D010710:Phosphates; D000255:Adenosine Triphosphate