title: Reduction in basal nitric oxide activity causes albuminuria.
abstract: OBJECTIVE
  The barrier function of the glomerular filter has been studied for decades. Albuminuria reflects a malfunction of this barrier, and in animals dysfunctional endothelial nitric-oxide (NO) synthase results in albuminuria. We aimed to analyze the importance of NO for the glomerular barrier function in humans.
  
  
  METHODS
  To assess the effect of endothelial dysfunction on albuminuria, we measured the urine albumin-to-creatinine ratio (UACR) both before and after the blockade of NO synthases (NOSs) with systemic infusion of N(G)-monomethyl-L-arginine (L-NMMA) in two distinct study populations. In population A, 62 hypertensive patients with type 2 diabetes and, in population B, 22 patients with hypercholesterolemia but without hypertension or type 2 diabetes were examined. All subjects had normal renal function.
  
  
  RESULTS
  There was a significant increase in the UACR in response to NOS inhibition with L-NMMA in hypertensive patients with type 2 diabetes (study population A) and in patients with hypercholesterolemia (study population B). Linear regression analyses revealed that the change in mean arterial presssure in response to L-NMMA was not related to the increase in the UACR in response to L-NMMA in either population, even after adjusting for filtration fraction.
  
  
  CONCLUSIONS
  NOS inhibition provokes albuminuria that is unrelated to changes in blood pressure. It is noteworthy that this finding was evident in patient groups prone to endothelial dysfunction and albuminuria. Thus, acute deterioration of endothelial function by reducing NO activity causes an increase in albuminuria.
authors.affiliation: Department of Nephrology and Hypertension, University of Erlangen-Nürnberg, Erlangen, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Ott
authors.forename: Markus P
authors.initials: MP
authors.lastname: Schneider
authors.forename: Christian
authors.initials: C
authors.lastname: Delles
authors.forename: Markus P
authors.initials: MP
authors.lastname: Schlaich
authors.forename: Roland E
authors.initials: RE
authors.lastname: Schmieder
mesh_terms: D000368:Aged; D000418:Albumins; D000419:Albuminuria / Q000139:chemically induced / Q000378:metabolism* / Q000503:physiopathology; D001794:Blood Pressure / Q000187:drug effects; D003404:Creatinine / Q000652:urine; D003924:Diabetes Mellitus, Type 2 / Q000378:metabolism* / Q000503:physiopathology; D005260:Female; D006801:Humans; D006937:Hypercholesterolemia / Q000378:metabolism* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors*; D012044:Regression Analysis; D019323:omega-N-Methylarginine / Q000494:pharmacology
chemical_list: D000418:Albumins; D019323:omega-N-Methylarginine; D009569:Nitric Oxide; D003404:Creatinine; D019001:Nitric Oxide Synthase