Wheal-and-flare responses to intradermally injected adenosine 5'-monophosphate, hypertonic saline, and histamine: comparison of atopic and nonatopic subjects

Abstract

Adenosine 5'-monophosphate (AMP) in increasing concentrations, and saline solutions of corresponding tonicity, were injected intradermally in seven atopic and seven normal subjects. Skin wheal-and-flare responses were elicited in a dose-dependent fashion in all subjects, and no difference was found between responses produced by AMP and responses produced by saline of corresponding tonicity. Also, no difference in response to AMP and saline was found between atopic and nonatopic subjects. We further investigated, in seven atopic subjects, whether the skin wheal-and-flare response to the single, highest dose of AMP, saline, and histamine could be inhibited by preadministration of 180 mg of terfenadine, a potent H1 antagonist. A significant inhibition of the wheal-and-flare response to histamine and no significant inhibition to AMP were found. There was a significant inhibition of the flare response caused by hypertonic saline but no inhibition of the wheal response. We interpret these findings as indicating that AMP does not specifically lead to mast cell degranulation in the skin and that there are functional differences between cutaneous and lung mast cells. The observation that terfenadine significantly inhibited the flare response to hypertonic saline suggests that this stimulus produced histamine release.