Inhibitory Effects of Formaldehyde Inhalation on the Cardiovascular and Respiratory Systems in Unanesthetized Rabbits

• Published in: Japanese journal of pharmacology Vol. 40; no. 4; pp. 551 - 559
• Main Authors: TANI, Takayuki, KOGI, Kunitarou, HORIGUCHI, Yoshiya
• Format: Journal Article
• Language: English
• Published: Kyoto The Japanese Pharmacological Society 1986; Japanese Pharmacological Society
• Subjects: Animals; Atropine - pharmacology; Biological and medical sciences; Chemical and industrial products toxicology. Toxic occupational diseases; Formaldehyde - toxicity; Guanethidine - pharmacology; Heart Rate - drug effects; Hemodynamics - drug effects; Lidocaine - pharmacology; Male; Medical sciences; Parasympatholytics - pharmacology; Phenoxybenzamine - pharmacology; Prazosin - pharmacology; Rabbits; Respiration - drug effects; Sympatholytics - pharmacology; Toxicology; Various organic compounds; Reflex; Arrhythmia; Toxicity; Rabbit; Lagomorpha; Respiratory system; Formaldehyde; Inhalation; Vertebrata; Bradycardia; Nerve ending; Mammalia; Animal; Neurotransmitter; Circulatory system
• ISSN: 0021-5198; 1347-3506
• DOI: 10.1254/jjp.40.551

The mechanisms of the marked inhibitory effects of 10 ppm formaldehyde (HCHO) inhalation on heart rate and respiratory movement were investigated in unanesthetized rabbits. Inhibition of the heart rate and respiratory movement induced by HCHO inhalation was caused by a reflex reaction during sensory irritation of the upper respiratory tract, mainly the nasal mucosa, but not of the lower respiratory tract, mainly the lung. These reflex reactions, particularly decreases in the heart rate, were not blocked by vagotomy, atropine or prazosin, but were blocked by propranolol, phenoxybenzamine, phentolamme, yohimbine and guanethidine. These results suggest that these reflex reactions are derived from sympathetic nervous activity rather than parasympathetic nervous activity, and the reflex bradycardia is caused by inhibiting the transmitter release at the adrenergic nerve endings.