Proton NMR spectroscopy of rabbit renal cortex

High resolution 1H-NMR spectra were obtained from renal cortical slices, homogenates, isolated cells in suspension, and lysates. Experimental conditions for acquisition of high resolution spin-echo spectra are described and assignments of prominent peaks to various metabolites are given. The in situ activity of the highly active cortical enzyme prolidase was determined (1.8 nmoles/min/mg wet kidney wt) by exploiting the marked difference in the spectral features of glycyl-L-proline and that of the free amino acids. The results suggest that this NMR method will be applicable generally to the study of hydrolysis of peptides, as well as to other metabolic processes both in vitro and in vivo.