Effects of Cedrol inhalation on autonomic functions in laryngectomized patients

Abstract

Previously we reported effects of Cedrol inhalation on autonomic functions; Cedrol increased parasympathetic activity and decreased sympathetic activity in healthy young human subjects. In the present study, to investigate sites of action of Cedrol effects, we analyzed autonomic functions during inhalation of Cedrol fumes using healthy young and anosmic subjects, and patients with total laryngectomy. Vaporized crystalline Cedrol and blank air were presented to the subjects via a face mask. The results indicated similar effects of Cedrol in young healthy and anosmic subjects; Cedrol significantly decreased heart rate (HR), systolic (SBP) and diastolic (DBP) blood pressure compared to blank air exposure. Spectral analysis of HR variability showed that Cedrol increased a high frequency (HF) component (index of parasympathetic activity), and decreased a ratio of low frequency (LF) to HF component (index of sympathetic activity). Furthermore, LF components of SBP and DBP decreased, suggesting sympathetic decrement. In the totally laryngectomized patients, Cedrol was directly inhaled into the lung through the trachea. In 6 of the 7 patients Cedrol increased HF and in 5 of those it decreased LF of SBP. The results suggested that Cedrol activated the central nervous system partly through the peripheral nerves innervating the lower airway and pulmonary system, which resulted in autonomic changes. [Jpn J Physiol 54 Suppl:S195 (2004)]