Raised transaminase activity of blood plasma from rats with experimentally-induced kidney damage detected by spin-echo 1H-NMR spectroscopy

Abstract We report the application of spin-echo 1 H-NMR spectroscopy to the detection of raised plasma transaminase activity in rats treated with the nephrotoxic cephalosporin antibiotic cephaloridine (CPH). Spin-echo 1 H-NMR analysis of lyophilized plasma, reconstituted in H 2 0 reveals a doublet at δ 1.48 for alanine. However when samples were reconstituted with 2 H 2 0 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 δ 1.47 together with a reduction in the doublet at δ 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 α-hydrogen (α-CH) position. This observation suggests that these 1 H-NMR spectral patterns are dependent on the level of plasma transaminases and this may provide a novel indicator of tissue damage.