Role of titratable acidity in acid aerosol-induced bronchoconstriction

Journal Article · Wed Apr 01 04:00:00 EST 1987 · Am. Rev. Respir. Dis.; (United States)

DOI:https://doi.org/10.1164/arrd.1987.135.4.826· OSTI ID:6786091

Fine, J M; Gordon, T; Thompson, J E; Sheppard, D

We evaluated the importance of pH, titratable acidity, and specific chemical composition in acid aerosol-induced bronchoconstriction in 8 asthmatic subjects. We administered aerosols of HCl and H/sub 2/SO/sub 4/ at pH 2.0 in an unbuffered state and buffered with glycine. The buffered acids were given in order of increasing titratable acidity (defined as the number of ml of 1 N NaOH required to neutralize 100 ml of acid solution to pH 7.0). Each set of buffered or unbuffered acid aerosols was given on a separate day and each aerosol was inhaled through a mouthpiece during 3 min of tidal breathing. Bronchoconstriction was assessed by measurement of specific airway resistance (SRaw) before and after inhalation of each aerosol. SRaw increased by more than 50% above baseline in 1 of 8 subjects after inhalation of unbuffered HCl and in no subjects after inhalation of unbuffered H/sub 2/SO/sub 4/, even at pH 2.0. In contrast, SRaw increased by greater than 50% in all 8 subjects after inhalation of HCl and glycine at pH 2.0 and 7 of 8 subjects after inhalation of H/sub 2/SO/sub 4/ and glycine at pH 2.0. The mean titratable acidity required to increase SRaw by 50% above baseline was calculated for each challenge by linear interpolation; these values for H/sub 2/SO/sub 4/ and glycine (5.1 ml of 1 N NaOH) and HCl and glycine (2.2 ml of 1 N NaOH) were slightly, but significantly, different (p = 0.01) and were considerably higher than the titratable acidity of the unbuffered acids at pH 2 (1.0 ml of 1 N NaOH).

• Research Organization: Cardiovascular Research Institute, San Francisco, CA
• OSTI ID: 6786091
• Journal Information: Am. Rev. Respir. Dis.; (United States), Journal Name: Am. Rev. Respir. Dis.; (United States) Vol. 4; ISSN ARDSB
• Country of Publication: United States
• Language: English

Related Subjects

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59 BASIC BIOLOGICAL SCIENCES
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
AEROSOLS
AIR POLLUTION
ASTHMA
BRONCHI
BUFFERS
COLLOIDS
DISEASES
DISPERSIONS
HYDROCHLORIC ACID
HYDROGEN COMPOUNDS
INHALATION
INORGANIC ACIDS
INTAKE
PATHOGENESIS
PH VALUE
POLLUTION
RESPIRATORY SYSTEM
RESPIRATORY SYSTEM DISEASES
SOLS
SULFURIC ACID
TOXICITY
VASOCONSTRICTION