title: Nitric oxide synthetic capacity in relation to dialysate temperature.
abstract: BACKGROUND
  During hemodialysis, vascular reactivity is impaired, which can be corrected by lowering dialysate temperature. It has also been shown that nitric oxide (NO) is related to intradialytic hypotension. As NO synthesis may be temperature-dependent, this study addressed the influence of dialysate temperature on the NO synthetic capacity of plasma.
  
  
  METHODS
  NO synthetic capacity was studied during hemodialysis with a dialysate temperature of 37.5 degrees C (dialysis-37.5 degrees C) and programmed extracorporeal blood cooling (cool dialysis; Blood Temperature Monitor; Fresenius C) in 12 stable patients. NO synthetic capacity was assessed ex vivo by [3H]L-citrulline formation from [3H]L-arginine in cultured endothelial cells after incubation with plasma samples obtained during the respective sessions.
  
  
  RESULTS
  Core temperature decreased (-0.32 +/- 0.10 degrees C) and energy transfer rate was significantly lower (-27.5 +/- 2.8 W; p < 0.05) during cool dialysis compared to dialysis-37.5 degrees C (0.19 +/- 0.06 degrees C and -0.8 +/- 1.2 W respectively; p < 0.05). Systolic blood pressure decreased during dialysis-37.5 degrees C (-19 +/- 4 mm Hg; p < 0.05), but not during cool dialysis (-6 +/- 5 mm Hg). NO synthetic capacity increased during dialysis-37.5 degrees C (55.5 +/- 9.3 to 73.5 +/- 10.2 pmol/10(5) cells; p < 0.05), in contrast to cool dialysis (67.3 +/- 11.1 to 66.2 +/- 10.8 pmol/10(5) cells).
  
  
  CONCLUSIONS
  The stimulatory effect of uremic plasma on endothelial NO synthesis was augmented during dialysis-37.5 degrees C but not during cool dialysis.
authors.affiliation: Department of Internal Medicine, University Hospital Maastricht, Maastricht, The Netherlands.
authors.forename: Charles H
authors.initials: CH
authors.lastname: Beerenhout
authors.forename: Marina
authors.initials: M
authors.lastname: Noris
authors.forename: Jeroen P
authors.initials: JP
authors.lastname: Kooman
authors.forename: Francesca
authors.initials: F
authors.lastname: Porrati
authors.forename: Elena
authors.initials: E
authors.lastname: Binda
authors.forename: Marina
authors.initials: M
authors.lastname: Morigi
authors.forename: Otto
authors.initials: O
authors.lastname: Bekers
authors.forename: Frank M
authors.initials: FM
authors.lastname: van der Sande
authors.forename: Marta
authors.initials: M
authors.lastname: Todeschini
authors.forename: Daniela
authors.initials: D
authors.lastname: Macconi
authors.forename: Karel M L
authors.initials: KM
authors.lastname: Leunissen
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Remuzzi
mesh_terms: D000368:Aged; D001120:Arginine / Q000032:analysis / Q000378:metabolism; D004730:Endothelium, Vascular / Q000201:enzymology; D004735:Energy Transfer; D005260:Female; D006439:Hemodynamics; D006801:Humans; D007674:Kidney Diseases / Q000201:enzymology / Q000378:metabolism / Q000628:therapy; D008297:Male; D008875:Middle Aged; D009569:Nitric Oxide / Q000096:biosynthesis*; D019001:Nitric Oxide Synthase / Q000378:metabolism*; D052250:Nitric Oxide Synthase Type III; D006435:Renal Dialysis / Q000009:adverse effects*; D013696:Temperature
chemical_list: D009569:Nitric Oxide; D001120:Arginine; C496314:NOS3 protein, human; D019001:Nitric Oxide Synthase; D052250:Nitric Oxide Synthase Type III