THE EFFECT OF NOSE DROPS ON AN ACUTE SINUSITIS - AN EXPERIMENTAL-STUDY IN THE RABBIT

An animal model was developed to study the effect of nose drops on an acute sinusitis. Leukocyte-stimulating n-formylmethionyl-leucyl-phenylalanine (FMLP) was added to polyvinyl sponges and placed bilaterally into the maxillary sinuses of the rabbit. Oxymetazoline nose drops were applied in one nasal cavity, on the contralateral side, using the application of saline as control. After 2 hours, the animals were killed, and the sponges were removed for analysis of leukocyte content by light microscopy and determination of myeloperoxidase (MPO), an intracellular enzyme in polymorphonuclear leukocytes. The sinus mucosa was dissected bilaterally and prepared for whole-amount light microscopy. There was a reduced number of leukocytes in the sinus mucosa on the side treated with oxymetazoline nose drops compared with the contralateral side. No significant differences were found in the number of leukocytes or MPO in the sponges. The effect of oxymetazoline may be due to its blood-flow-reducing effect or an effect on the endothelium in the microvascular bed.