Efficacy of β-Adrenergic Blocking Agents in inducing Histamine Sensitivity in Mice

Abstract

THE usually high resistance of mice to the lethal effects of histamine can be greatly reduced in certain strains by some substances. The most potent of these histamine sensitizing substances is probably the so-called histamine sensitizing factor (HSF) of Bordetella pertussis¹. Recently, substances with β-adrenergic blocking activity, such as dichloroiosoproterenol (DCI), pronethalol (‘Alderlin’^R) and 4-(2-isopropyl-amino-1-hydroxyethyl) methane sulphonanilide HCl (MJ-1999), have also been shown to increase the sensitivity of mice to histamine^2,3. Some of these agents, such as DCI, have been found highly effective in reducing histamine tolerance². Preliminary work with DCI and the CFW strain of mice, reared in our laboratory, confirmed that treating mice with DCI does induce histamine sensitivity, but we did not find that DCI was effective in the small doses (0.005 mg/kg) reported by Fishel et al.². With the advent of other β-adrenergic blocking agents, we felt it would be of value to test the histamine sensitizing effects of these agents and to determine if some were more efficient in this respect than others. In order to duplicate more closely the experimental conditions used by Fishel et al.², we used female CFW mice obtained from Carworth Farms, New City, New York.