Functional disturbances of the sympathetic nerve in experimentally-induced nasal hypersensitivity

Norepinephrine, alpha-1 and beta adrenergic receptors in the nasal mucosa of toluene-diisocyanate sensitized guinea-pigs were evaluated quantitatively at specific points in time during a pre-determined sensitization period. At 4, 8 and 12 weeks, the norepinephrine content was reduced. The concentration of alpha-1 adrenergic receptors significantly decreased in 8- and 12-week groups. A lower density of beta adrenergic receptors was shown in the 12-week group. Signs of a return to normalcy were observed by four weeks post-sensitization. These results led us to speculate that excess norepinephrine release, which may be promoted by allergy-inducing histamine, depleted the norepinephrine at the sympathetic nerve terminal and caused a lowering of the concentration of sympathetic receptors. Functional disturbance of the sympathetic nerve was suggested by clinical findings of nonspecific nasal hypersensitivity, congestion and nasal discharge.