H-1-NMR SPECTROSCOPIC INVESTIGATIONS OF TISSUE METABOLITE BIOMARKER RESPONSE TO CU(II) EXPOSURE IN TERRESTRIAL INVERTEBRATES - IDENTIFICATION OF FREE HISTIDINE AS A NOVEL BIOMARKER OF EXPOSURE TO COPPER IN EARTHWORMS
Jot. Gibb et al., H-1-NMR SPECTROSCOPIC INVESTIGATIONS OF TISSUE METABOLITE BIOMARKER RESPONSE TO CU(II) EXPOSURE IN TERRESTRIAL INVERTEBRATES - IDENTIFICATION OF FREE HISTIDINE AS A NOVEL BIOMARKER OF EXPOSURE TO COPPER IN EARTHWORMS, Biomarkers, 2(5), 1997, pp. 295-302
High resolution H-1 NMR spectroscopy of biofluids, cells and tissue ex
tracts allows rapid, non-destructive analysis fdr a wide range of meta
bolites and organic compounds with minimal sample pre-treatment. We ha
ve applied high resolution 1H NMR spectroscopy to investigate the bioc
hemical effects of Cu(ll) in two earthworm species Eisenia andrei (n=7
8) and Lumbricus rubellus (n=45) exposed under laboratory and semi-fie
ld conditions respectively. The most marked metabolic response was the
elevation of endogenous whole body free histidine in animals which po
sitively correlated with increasing copper exposure and total copper b
urden in the semi-field experiment. Histidine forms thermodynamically
stable copper complexes under a wide range of physico-chemical conditi
ons and we proposed that the elevation of free histidine in response t
o copper challenge provides an energetically 'low-cost' detoxification
mechanism. Histidine elevation may also provide a novel molecular bio
marker of Cu(ll) exposure in environmental situations.