Locally deposited but not inhaled frusemide reduces nasal potential difference in healthy subjects

Mialon, P.; Charfi, Rim; Régnard, Jean-François; Lockhart, A; Dinh-Xuan, Anh Tuan

doi:10.1007/bf00265953

Cited by 5 publications

(2 citation statements)

References 28 publications

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“…For measurement of nasal PD each patient underwent two measurements in random order, one with Ag/AgCl electrodes and the other with conventional electrodes perfused with Ringer’s lactate and prepared as previously described 7. The exploring electrode was positioned 3–4 cm from the anterior tip of the turbinate until a maximal and stable PD for over 10 s was obtained.…”

Section: Methodsmentioning

confidence: 99%

Silver/silver chloride electrodes for measurement of potential difference in human bronchi

Fajac

Lacronique

Lockhart

et al. 1998

Thorax

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Background-An easy and reliable method to measure potential diVerence (PD) in the lower airways would be of interest in the field of cystic fibrosis. We have developed silver/silver chloride (Ag/ AgCl) electrodes to measure PD in the lower airways. (Thorax 1998;53:879-881) Keywords: silver/silver chloride electrodes; potential diVerence; airways A transepithelial electric potential diVerence (PD) across mammalian airway epithelium is generated by electrogenic ion transport. Methods-To validate this technique1 Nasal PD can be measured in vivo in humans and is higher in patients with cystic fibrosis than in normal control subjects.2 3 Although it would be of interest in the field of cystic fibrosis and especially in gene therapy studies to be able to measure PD easily in the lower airways, few studies published a decade ago have attempted to measure PD in the bronchi. [4][5][6] In these studies PD was recorded during fibreoptic bronchoscopy with the same type of Ringer's perfused electrodes as are used in the nose. With these electrodes we have attempted to measure transepithelial PD in the lower airways of eight subjects during fibreoptic bronchoscopy. However, in this preliminary study we found it diYcult to obtain stable and reproducible PD values in the lower airways, mostly because of air bubbles that formed at the tip of the very thin electrode and because of an early flooding of the airway lumen by the perfused fluid. In the present study we have therefore prepared silver/silver chloride (Ag/AgCl) nonpolarisable electrodes to measure more easily transepithelial PD in the lower airways. Methods EXPERIMENTAL DESIGN AND SUBJECTSThe agreement between Ag/AgCl electrodes and perfused electrodes was determined by measurement of nasal PD with both methods in 16 adult patients (six men) of mean (SD) age 51 (19) years. The range of PD in the lower airways was determined with Ag/AgCl electrodes in 14 adult patients (six men) of mean (SD) age 60 (19) years during fibreoptic bronchoscopy required because of lung cancer (n = 8) or interstitial lung disease (n = 6). In nine of these 14 patients the reproducibility of PD measurements with Ag/AgCl electrodes was determined by two measurements at five minute intervals at the same location of the distal trachea.The investigation conformed to the regulations of the Institutional Ethics Committee. PREPARATION OF AG/AGCL WIRE ELECTRODESSilver wires were used to prepare the Ag/AgCl electrodes (World Precision Instruments, Hertfordshire, UK). The silver wire was inserted into a Teflon catheter (Bioblock Scientific, Illkirch, France; fig 1). The end of the silver wire was heated to form a small atraumatic bead which was covered by a layer of silver chloride by anodising in HCl solution using a potentiostat/galvanostat. Two new Ag/AgCl electrodes were prepared for each patient and sterilised by autoclaving. One served as a reference bridge and the silver bead was taped on to a scarification on the skin at the anterior face of the forearm. The other electrode served as th...

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Section: Methodsmentioning

confidence: 99%

Silver/silver chloride electrodes for measurement of potential difference in human bronchi

Fajac

Lacronique

Lockhart

et al. 1998

Thorax

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“…No patient was studied within 4 weeks of acute infectious rhinitis. The technique used has been described previously [13]. In brief, the reference bridge was made of polyethylene tubing (1 mm i.d., Vygon, Ecouen, France) filled with Ringer's solution and taped to the skin such that the solution dripped slowly onto a scarification on the anterior face of the forearm.…”

Section: Measurement Of Nasal Potential Differencementioning

confidence: 99%

Relationships between nasal potential difference and respiratory function in adults with cystic fibrosis

Fajac¹,

Hubert²,

Bienvenu³

et al. 1998

Eur Respir J

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This study investigated the relations between nasal transepithelial electric potential difference (PD) and the phenotype and genotype of cystic fibrosis (CF) adult patients. Basal nasal PD was measured in 95 adult CF patients who were classified into three groups of nasal PD (expressed as absolute values) according to the 10th and the 90th percentiles (28.3 and 49.2 mV, respectively), which defined group 1 (nasal PD < or =28.3 mV), group 2 (nasal PD 28.3-49.2 mV) and group 3 (nasal PD > or =49.2 mV). Patients from group 1 had a higher forced vital capacity (FVC) than patients from groups 2 and 3 (76.5+/-22.4 versus 57.4+/-21.2 and 55.7+/-21.1% predicted, respectively, p<0.05) and a higher forced expiratory volume in one second (FEV1) (69.3+/-24.0 versus 42.5+/-22.4 and 42.2+/-21.4% pred, respectively, p<0.01). Among patients with severe mutations (deltaF508 homozygotes, or one deltaF508 mutation plus another "severe" mutation, or two "severe" mutations), patients from group 1 had a higher FVC, FEV1 and arterial oxygen tension than patients from groups 2 and 3 (p<0.05 for each comparison). The results show that in adult cystic fibrosis patients a normal basal nasal potential difference is related to milder respiratory disease, irrespective of the severity of the genotype.

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Extrarenal Effects of Diuretics

Palmer

1997

Diuretic Agents

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Locally deposited but not inhaled frusemide reduces nasal potential difference in healthy subjects

Cited by 5 publications

References 28 publications

Silver/silver chloride electrodes for measurement of potential difference in human bronchi

Silver/silver chloride electrodes for measurement of potential difference in human bronchi

Relationships between nasal potential difference and respiratory function in adults with cystic fibrosis

Extrarenal Effects of Diuretics

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