Effect of promethazine hydrochloride on bone resorption in tissue culture.

Abstract

AbstractThe effect of promethazine hydrochloride, an established macrophage inhibitor, on bone resorption in tissue culture was examined. At nontoxic concentrations (5–25 μg/ml), promethazine hydrochloride inhibited, in a dose–response fashion, parathyroid extract-stimulated bone resorption and bone resorption in a bone remodeling system. Histological examination of sections prepared from cultured bones treated both with parathyroid extract and promethazine hydrochloride revealed an increase in number of macrophages in promethazine hydrochloride-treated cultures. At higher concentrations of this compound, but still within the same range of generally nontoxic concentrations (5–25 μg/ml), the macrophages appeared to be damaged. It is suggested that promethazine hydrochloride inhibits bone resorption in tissue culture by impairing macrophage function.