Kidney retrieval conditions influence damage to renal medulla: Evaluation by proton nuclear magnetic resonance (NMR) pectroscopy

In the present investigation, the influence of retrieval condition on medul lary damage in kidneys was assessed. The isolated perfused pig kidney was u sed to assess initial renal function from multiorgan donors or single organ donors after cold flush and 24 h cold storage preservation with two preser vation solutions: Euro-Collins and University of Wisconsin solutions. Kidne ys flushed with cold heparinized saline and immediately perfused were used as a control group. Kidneys were perfused for 90 min at 37.5 degreesC and r enal perfusion Row rate, glomerular filtration rate, tubular reabsorption o f Na+ and lactate dehydrogenase and Nacetyl-beta -D-glucosaminidase excreti on were determined. Ischaemia reperfusion impairment was also determined by H-1 NMR (proton nuclear magnetic resonance) spectroscopy. Renal function w as significantly decreased in experimental groups when compared to the cont rol group, but there was no significant difference between experimental gro ups after 24 h cold storage. The release of lactate dehydrogenase in the ef fluent and the urinary excretion of N-acetyl-beta -D-glucosaminidase were n ot significantly different after 24 h cold storage. The most relevant reson ances determined by H-1 NMR spectroscopy were citrate, trimethylamine-N-oxi de. lactate, acetate and amino acids. Excretion of these markers was signif icantly different when compared to biochemical markers. A resonance P (Peak ) detected particularly in Euro-Collins solution multiorgan donors after 24 h cold storage was identified and well correlated to renal dysfunction. N- acetyl-beta -D-glucosaminidase spectroscopy, which is a non-invasive and no n-destructive technique, is more efficient to assess renal damage than conv entional histology and biochemical analysis.