RAISED TRANSAMINASE-ACTIVITY OF BLOOD-PLASMA FROM RATS WITH EXPERIMENTALLY-INDUCED KIDNEY DAMAGE DETECTED BY SPIN-ECHO H-1-NMR SPECTROSCOPY

We report the application of spin-echo H-1-NMR spectroscopy to the detection of raised plasma transaminase activity in rats treated with the nephrotoxic cephalosporin antibiotic cephaloridine (CPH). Spin-echo H-1-NMR analysis of lyophilized plasma, reconstituted in H2O reveals a doublet at delta 1.48 for alanine. However when samples were reconstituted with (H2O)-H-2 we noted that in samples from CPH-treated rats (but not in control samples) there was a variable degree of appearance of a singlet at delta 1.47 together with a reduction in the doublet at delta 1.48. We suggest that this is due to the release of transaminases from damaged tissue which, via a reversible conversion of alanine to pyruvate, causes selective deuteration of alanine at the alpha-hydrogen (alpha-CH) position. This observation suggests that these H-1-NMR spectral patterns are dependent on the level of plasma transaminases and this may provide a novel indicator of tissue damage.