Impact of uninephrectomy on body L‐arginine homeostasis and blood pressure control (1136.14)

Abstract

L‐arginine plays an important role, acting as a precursor for a variety of physiologically important substances including citrulline, urea, ornithine, proline and nitric oxide and the kidney is a major site for its metabolism. Uninephrectomy (UNX) is observed to cause an increase in the size of the remnant kidney and compensation to some degree of the glomerular filtration rate. As very little is known about UNX‐induced effects on blood pressure control and expression levels of transporters and enzymes involved in arginine metabolism, we are testing in mice the hypothesis that renal mass reduction impacts on Arg metabolism and possibly thereby affects blood pressure control. Our results show that in contrast to sham operated controls, mice having undergone UNX display an increased systolic blood pressure (120 ± 2.14 vs. 112 ± 1.97 mmHg by tail cuff measurements, n = 18). This effect was more pronounced in females than males and observed also by telemetry. Plasma levels of asymmetric dimethyl arginine (ADMA), an inhibitor of NOS considered to be a good marker for renal disease, were increased in UNX animals, whereas the level of none of the proteinogenic amino acids was changed significantly. There were also no changes in the mRNA expression levels of Arg transporters and enzymes involved in arginine metabolism. Our observations suggest that UNX affects blood pressure and the effects are less pronounced in males, possibly due to a more important remnant kidney compensatory growth. Grant Funding Source: Supported by the Swiss NCCR Kidney.ch and the European Community's Seventh Framework Programme