Effect of BR-227, a new bromhexine derivative, on secretory activities of tracheal secretory cells.

Abstract

The effects of BR-227 on secretory activities of canine tracheal secretory cells including behavior of mucus glycoproteins were investigated histologically and histochemically. Following BR-227 treatment at a concentration of alcian blue at pH 2.5 and periodic acid-Schiff (AB (pH 2.5)/PAS) decreased in a concentration-dependent manner. Furthermore, a decrease in the thickness of the acini of submucosal glands and in marked increase in the ratio of acinar inner diameter of the gland to tracheal wall were induced after application of BR-227 at a concentration range of 10(-7) to 10(-4) M. The numbers of goblet and submucosal glandular cells which stained blue and purple with AB (pH 2.5)/PAS were decreased by BR-227 treatment in a concentrations-dependent way, whereas the cells which stained red were markedly increased. In the experiment using a combination of AB at pH 1.0 and PAS, a decrease in sulfated glycoproteins in those secretory cells was observed. Total saccharide and protein concentrations in the incubation fluid increased with BR-227 treatment, while N-acetylhexomsamine concentration tended to decrease. These findings suggest that BR-227 stimulates secretory activities of both goblet cells and submucosal glands, and lowers mucus viscosity in the secretory cells.