³¹P and ¹H NMR spectroscopic studies of liver extracts of carbon tetrachloride-treated rats

NMR spectroscopy was used to examine hepatic metabolism in cirrhosis with a particular focus on markers of functional cellular hypoxia. ³¹P and ¹H NMR spectra were obtained from liver extracts from control rats and from rats with carbon tetrachloride-induced cirrhosis. A decrease of 34% in total phosphorus content was observed in cirrhotic rats, parallelling a reduction of 40% in hepatocyte mass as determined by morphometric analysis. Hypoxia appeared to be present in cirrhotic rats, as evidenced by increased inorganic phosphate levels, decreased ATP levels, decreased ATP:ADP ratios (1.72 ± 0.40 vs 2.48 ± 0.50, p < 0.01), and increased inorganic phosphate:ATP ratios (2.77 ± 0.48 vs 1.62 ± 0.24, p < 0.00001). When expressed as a percentage of the total phosphorus content, higher levels of phosphoethanolamine and lower levels of NAD and glycerophosphoethanolamine were detected in cirrhotic rats. Cirrhotic rats also had increased phosphomonoester:phosphodiester ratios (5.73 ± 2.88 vs 2.53 ± 0.52, p < 0.01). These findings are indicative of extensive changes in cellular metabolism in the cirrhotic liver, with many findings attributable to the presence of intracellular hypoxia.