Experimental sinusitis in rabbits induced by aerobic and anaerobic bacteria: models for research in sinusitis.

Experimental acute sinusitis can be induced in New Zealand white rabbits by Streptococcus pneumoniae serotype 3, or the anaerobe Bacteroides fragilis, after blocking of the sinus ostium. Histological examination of the sinus mucosa in both models reveals edema, dilated venules, leukocytic infiltration, goblet cell formation, as well as localized epithelial lesions. In comparison the bacteroides sinusitis enhances a more pronounced and long-lasting tissue reaction, including periosteal thickening and new bone formation. The sinus mucosal blood flow as measured with microspheres Sn113 is increased as compared to control side in pneumococcal sinusitis. An increased lactate concentration of sinus secretions as well as in the pathological sinus mucosa indicates an anaerobic metabolism. Furthermore, a decreased ATP-content of the sinus mucosa suggests an energy depletion which could impair epithelial function. The anaerobic milieu of the sinus secretion is probably created by the leukocytes as analyzed by the separation of the D- and L-form of lactate.