Natural abundance 13C-NMR study of liver regeneration in rats.

13C-NMR spectra of liver samples of partially hepatectomized rats have been obtained at 50 MHz. The tissue specimens, fixed in buffered formaldehyde solution, were obtained for NMR spectroscopy at various time intervals between 6 and 72 hours after hepatectomy. Several metabolites were identified from the spectra and their concentrations were determined as a function of time. Neutral lipids increase dramatically in the first two days, to drop thereafter to normal; glycogen and glucose disappear in the first hours after surgery to appear again around 12-24 hours. The level of beta-hydroxybutyrate decreases almost to zero in the first 48 hours and then increases again, while lactic acid seems to remain essentially constant in the first 24-36 hours and to increase markedly at later times. Several other resonances have been identified. The metabolic changes detected by NMR closely correspond to the known biochemical data on liver regeneration.