Effect of Ammonia on Nasal Resistance in Atopic and Nonatopic Subjects

Abstract

Nasal airway resistance (NAR) was assessed from the slope of pressure-glow curves obtained during normal nasal breathing. Volunteers were classified as atopic or nonatopic according to strict critera. 100 ppm NH3 was introduced into each nostril for periods ranging from 5 to 30 seconds with frequent NAR monitoring. A progressive increase in NAR responses was obtained with incremental NH3 exposure, but no significant difference was noted between the mean response of atopic and nonatopic subjects. Control exposures to compressed air under the same pressure generally produced only a small change in NAR, while aerosolized buffered saline increased NAR more than compressed air. The nasal response to NH3 was effectively inhibited by intranasal atropine administration but not by chlorpheniramine. The nasal response to NH3 was effectively inhibited by intranasal atropine administration but not by chlorpheniramine. The described procedure provides a safe and simple method for studying semiquantitatively the short-term effects of inhaled irritants on the nose.

Chlorine inhalation produces nasal congestion in allergic rhinitics without mast cell degranulation

“…Given the findings reported here, downgrading the potential role of mast cell degranulation, along with findings by the author (and others) that cholinergic blockade does not diminish the nasal congestive response to irritants, the local (axon) reflex emerges as a credible mechanism for irritantinduced nasal congestion [13,23,24]. In animal experiments, neuropeptides have been implicated in the airway response to irritants in cigarette smoke [25].…”

Influence of Age, Gender, and Allergy Status on Nasal Reactivity to Inhaled Chlorine

“…Despite the link between physiologic reactivity to irritants and nasal allergy status, mast-cell degranulation seems unlikely in light of nasal lavage findings after provocation with both environmental tobacco smoke (Bascom et al, 1991) and Cl 2 . Further, cholinergic parasympathetic reflexes seem to have variable role in this phenomenon, based on studies in which cholinergic blockers were administered prior to provocation with ammonia (McLean et al, 1979) versus Cl 2 . Interest has been expressed in the potential involvement of vasoactive neuropeptides released by sensory nerves (Bascom, 1992).…”

Relationship between Density of Muscarinic Receptors and Nasal Hypersecretion in a Nasal Allergic Model

“…In fact, an increase in density of muscarinic acetylcholine receptor (m-ACh•R) and a de crease in densities of al (a,-R) and /9-adrenergic recep tors (f3•R) were observed in the nasal mucosa of pa tients with nasal allergy (5)(6)(7). It is widely known that the nasal mucosa shows not only specific hyperreactivity to allergens but also non-specific hypersensitivity and hyperreactivity to neuromediators (8,9), to irritants (10) and to physical stimuli (11). Thus, the changes in the expression of autonomic nerve receptors seem to be related to the appearance of hypersensitivity in the na sal mucosa.…”