Effects of Diphenhydramine, Naphazoline and m-Amino-α(1-Aminoethyl)Benzyl Alcohol Dihydrochloride on the Nasal Mucosa Determined by Impedance Method: a Simple Method for Evaluation of Nasal Decongestant

Publisher Website
Google Scholar
Abstract
A simple, new method was devised for evaluating nasal decongestants. In anesthetized dogs, 2 needle electrodes were inserted bilaterally into the superficial mucosa of the nasal wings. An impedance plethysmograph provided with a DC output was used to measure impedance between the 2 electrodes. When 1% histamine solution was sprayed into a nostril focusing on the inside mucosa of a nasal wing, impedance decreased markedly and thereafter recovered to a control level within 1-1.5 h. Comparable responses were obtained when the same solution was sprayed into the opposite nostril. The drugs to be tested were administered i.v. or topically between these 2 histamine applications. I.v. administrations of diphenhydramine (0.5 mg/kg) and m-amino-.alpha.(1-aminoethyl)benzyl alcohol dihydrochloride (0.1 mg/kg) inhibited the histamine effect completely. Pretreatment with naphazoline administered topically also inhibited impedance changes caused by histamine application. Local applications of acetylcholine (10%) and bradykinin (0.1%) did not change nasal impedance significantly in any instances.