title: Influence of perfusate temperature on nasal potential difference.
abstract: Nasal potential difference (NPD) quantifies abnormal ion transport in cystic fibrosis. It has gained acceptance as an outcome measure for the investigation of new therapies. To quantify the effect of solution temperature on NPD, we first examined the effect of switching from room temperature (20-25°C) to warmed (32-37°C) solutions and vice versa during each perfusion step. Secondly, standard protocols were repeated at both temperatures in the same subjects. Changing solution temperature did not alter NPD during perfusion with Ringer's solution (<1 mV) (p>0.1). During perfusion with zero chloride solution, changing from room temperature to warmed solutions tended to decrease absolute NPD (i.e. it became less negative) by 0.9 mV (p>0.1); changing from warmed to room temperature increased NPD by 2.1 mV (p<0.05). During isoprenaline perfusion, changing from room temperature to warmed solutions increased NPD by 1.5 mV (p<0.01) and from warmed to room temperature decreased NPD by 1.4 mV (p<0.05). For full protocols at room temperature or warmed in the same subjects, mean values were similar (n = 24). During warmed perfusion, group results for total chloride response had a larger standard deviation. As this increased variability will probably decrease the power of trials, this study suggests that solutions at room temperature should be recommended for the measurement of NPD.
authors.affiliation: University Medical Centre Utrecht, Utrecht, The Netherlands.
authors.forename: Inez
authors.initials: I
authors.lastname: Bronsveld
authors.forename: François
authors.initials: F
authors.lastname: Vermeulen
authors.forename: Dorotha
authors.initials: D
authors.lastname: Sands
authors.forename: Teresinha
authors.initials: T
authors.lastname: Leal
authors.forename: Anissa
authors.initials: A
authors.lastname: Leonard
authors.forename: Paola
authors.initials: P
authors.lastname: Melotti
authors.forename: Yasmin
authors.initials: Y
authors.lastname: Yaakov
authors.forename: Roel
authors.initials: R
authors.lastname: de Nooijer
authors.forename: Kris
authors.initials: K
authors.lastname: De Boeck
authors.forename: Isabelle
authors.initials: I
authors.lastname: Sermet
authors.forename: Michael
authors.initials: M
authors.lastname: Wilschanski
authors.forename: Peter G
authors.initials: PG
authors.lastname: Middleton
mesh_terms: D000293:Adolescent; D000328:Adult; D000584:Amiloride / Q000493:pharmacokinetics; D018118:Chloride Channels / Q000187:drug effects*; D002712:Chlorides / Q000493:pharmacokinetics*; D003550:Cystic Fibrosis / Q000473:pathology; D064368:Healthy Volunteers; D006801:Humans; D017136:Ion Transport; D007477:Ions; D007545:Isoproterenol / Q000493:pharmacokinetics; D008875:Middle Aged; D009297:Nasal Mucosa / Q000502:physiology*; D010477:Perfusion; D013696:Temperature; D013997:Time Factors; D055815:Young Adult
chemical_list: D018118:Chloride Channels; D002712:Chlorides; D007477:Ions; D000584:Amiloride; D007545:Isoproterenol