title: Exhaled oral and nasal nitric oxide during L-arginine infusion in preeclampsia.
abstract: OBJECTIVE
  To determine the effects of the nitric oxide (NO) precursor L-arginine on the airway NO concentration in patients with preeclampsia.
  
  
  METHODS
  NO was measured by a noninvasive chemiluminescence technique in air sampled directly from nasal and oral cavities during expiration before and during L-arginine infusion in 9 preeclamptic and 10 control pregnancies. Maternal blood pressure and heart rate were simultaneously recorded, and blood was sampled for analyses of cyclic guanosine monophosphate (cGMP) and nitrate.
  
  
  RESULTS
  Basal nasal and orally exhaled NO and the increment in nasal NO concentration during L-arginine infusion were similar in both groups. Basal plasma and platelet cGMP concentrations were similar in both groups. Following L-arginine infusion, plasma cGMP levels were significantly higher in preeclamptics (p < 0.01), while platelet cGMP was unaffected in both groups. Basal plasma nitrate was significantly higher in preeclamptics (p < 0.01), and this difference was not altered following infusion. Blood pressure and heart rate remained unaffected by the procedure in both groups.
  
  
  CONCLUSIONS
  Blood pressure did not decrease in the preeclamptics following L-arginine infusion, despite a significant increase in nasal NO sampled during breathhold and a concomitant increase in plasma cGMP, possibly reflecting an endogenous NO production. These results do not support the idea of a generalized decrease in NO production being a major cause of hypertension in preeclampsia.
authors.affiliation: Department of Obstetrics and Gynecology, Huddinge University Hospital, Huddinge, Sweden. charlotta.grunewald@obgyn.hs.sll.se
authors.forename: C
authors.initials: C
authors.lastname: Grunewald
authors.forename: K
authors.initials: K
authors.lastname: Carlström
authors.forename: G
authors.initials: G
authors.lastname: Kumlien
authors.forename: A
authors.initials: A
authors.lastname: Ringqvist
authors.forename: J
authors.initials: J
authors.lastname: Lundberg
mesh_terms: D000328:Adult; D001120:Arginine / Q000378:metabolism*; D001794:Blood Pressure; D001944:Breath Tests; D006152:Cyclic GMP / Q000097:blood; D005260:Female; D006339:Heart Rate; D006801:Humans; D008163:Luminescent Measurements; D009055:Mouth; D009566:Nitrates / Q000097:blood; D009569:Nitric Oxide / Q000032:analysis* / Q000096:biosynthesis; D009666:Nose; D011225:Pre-Eclampsia / Q000378:metabolism*; D011247:Pregnancy
chemical_list: D009566:Nitrates; D009569:Nitric Oxide; D001120:Arginine; D006152:Cyclic GMP