Na/K-ATPase in rabbit paranasal sinus mucosa during induced sinusitis

The Source of Lactic Acid in Experimental Sinusitis

Increased levels of L-lactate were found in secretions of the maxillary sinus in experimental sinusitis in rabbits. Analysis of certain epithelial metabolic enzymes in purulent sinusitis reveals an increased lactate dehydrogenase (LDH) activity in glands and epithelium. However, histochemically we could not find any decrease in oxidative enzyme capacity of the mucosal epithelium indicating an inadequate oxygen supply. In acute pneumococcal sinusitis, bacteria seem to resume a resting phase after a few days, and the lactate accumulation characteristic of the anaerobic milieu of the secretion appears to be mainly of leukocyte origin.

Submucosal glands after maxillary sinus surgery. An experimental study in rabbits

Thirty New Zealand White rabbits underwent unilateral partial or complete removal of maxillary sinus mucosa in order to evaluate submucosal maxillary sinus glands. After three months, specimens were taken for examination from all operated on and control sinuses. Bacteriological cultures, light and electron microscopy were performed. Histopathological findings showed a decrease in the number of serous glands and significant inflammation was present in the sinus in which there was complete surgical removal. Electron microscopy revealed changes in the secretory cells of the serous glands in the regenerated post-surgical mucosa.

Mucosal fine structure in experimental sinusitis

Rabbit maxillary sinuses were inoculated with Streptococcus pneumoniae and Bacteroides fragilis, and the histologic response in the sinus mucosa was observed over a 12-week period. An increased height of the cylindric cells and hyperplasia of the basal cells were frequent findings irrespective of the pathogen inoculated. The disease was found to influence the character of the secretory product from epithelial secretory cells and to degranulate the subepithelial glands. Ciliary loss was a transitional finding. A reduction in the number of mitochondria, the occurrence of deformed short microvilli, and cytoplasmic blebbing were seen in the cells devoid of normal cilia. It is inferred from this study that pneumococcal sinusitis in rabbits is a self-limiting process, and the mucosal sequelae of the acute infection are persisting goblet cells, slight focal fibrosis, and edema. Inoculation with B fragilis produces a chronic inflammatory process, with infiltration of mononuclear cells, luminal dilatation of the glands exhibiting zymogen granule depletion, and an increased thickness of the whole mucosal layer.