Differential effects of selective and non-selective NOS inhibition on renal arginine and protein metabolism during endotoxemia in rats

• Published in: Clinical nutrition (Edinburgh, Scotland) Vol. 21; no. 2; pp. 111 - 117
• Main Authors: HALLEMEESCH, M.M., COBBEN, D.C.P., SOETERS, P.B., DEUTZ, N.E.P.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.04.2002; Elsevier
• Subjects: Animals; Arginine - biosynthesis; Arginine - metabolism; Biological and medical sciences; Blood. Blood coagulation. Reticuloendothelial system; Development. Metamorphosis. Moult. Ageing; Disease Models, Animal; Endotoxemia - metabolism; Enzyme Inhibitors - pharmacology; Fundamental and applied biological sciences. Psychology; Isothiuronium - analogs & derivatives; Isothiuronium - pharmacology; Kidney - metabolism; Male; Medical sciences; Nephrology. Urinary tract diseases; Nephropathies. Renovascular diseases. Renal failure; NG-Nitroarginine Methyl Ester - pharmacology; Nitric Oxide - metabolism; Nitric Oxide Synthase - antagonists & inhibitors; Pharmacology. Drug treatments; Protein Biosynthesis; protein turnover, arginine production, nitric oxide synthase inhibition; Proteins - metabolism; Random Allocation; Rats; Rats, Wistar; Renal failure; Sepsis - metabolism; Specific Pathogen-Free Organisms; Vertebrates: anatomy and physiology, studies on body, several organs or systems; protein turnover, arginine production, nitric oxide synthase inhibition; Rat; Enzyme; Rodentia; Selectivity; Metabolism; Biological activity; Nitric-oxide synthase; Protein; Kidney; Infection; Vertebrata; Mammalia; Arginine; Aminoacid; Animal; Turnover; Oxidoreductases; Protein synthesis inhibitor; Endotoxemia
• DOI: 10.1054/clnu.2001.0513
• ISSN: 0261-5614

Background and aims: The kidney is the main endogenous producer of circulating arginine. Renal arginine disposal is directed to protein synthesis, urea production and nitric oxide synthesis. The administration of nitric oxide synthase inhibitors during sepsis may be beneficial or detrimental depending on the specificity of the inhibitor. We aimed to measure the effects of two NOS inhibitors, with different specificity, on renal arginine and protein turnover in a rat model of sepsis. Methods: Rats were subject to double hit endotoxemia and either L-NAME (non-specific), SMT (iNOS specific) or saline. Under anesthesia, vessels supplying and draining the kidney were catheterized. Systemic and intra-renal arginine and protein metabolism were measured using a primed continuous infusion of L-[2,3-3H]arginine and L-[2,6-3H]phenylalanine. Results: Non-specific NOS reduced systemic protein and arginine turnover, whereas selective iNOS inhibition did not. In the kidney, blood flow was reduced by L-NAME, but not by SMT. In conjunction with this, non-selective NOS inhibition increased renal protein breakdown, whereas selective iNOS inhibition increased renal arginine production. Conclusions: This study shows that non-selective NOS inhibition using L-NAME is detrimental for systemic and renal protein metabolism. Selective NOS inhibition stimulates renal arginine synthesis, without changing circulating arginine levels.