Changes in the Oxygen Uptake Rate in the Rat Olfactory Epithelium under the Influence of Odorants

Resumo

Abstract—This paper presents the results of a study of the oxygen supply to olfactory cells, which is required for olfactory signal transduction of chemical and mechanical stimuli triggered by olfactory receptors located in the membrane of sensory cilia that extend into the mucus layer that covers the olfactory epithelium. Experiments were conducted on olfactory epithelia isolated from male Wistar rats without symptoms of rhinitis. The oxygen uptake rate (pO₂) in the mucus covering the olfactory epithelium was measured using a micropolarographic method prior to a response to odor molecules, that is, a mixture of n-butanol and amyl alcohol, and during its stimulation. The results show that the oxygen uptake rate was almost four times higher in the mucus covering the olfactory epithelium than in the odor solution, suggesting an intense diffusion of oxygen through the olfactory mucus. It was also found that under the action of odorants, pO₂ in the mucus decreased from 43.1 ± 1.8 to 35.9 ± 1.8 mmHg (n = 53). Oxygen supply to olfactory flagella from the olfactory mucus in response to chemical and mechanical stimuli may be a prerequisite for high sensitivity and rapid kinetics of olfactory transduction processes.