Effects of formaldehyde on cardiac function.
This investigation examined the effect of formaldehyde (HCHO) on cardiac function in in vitro cardiac preparations and in situ hearts of guinea pigs and rabbits. Though HCHO (0.2-4 mg/kg, i.v.) produced noticeable bradycardiac and negative inotropic responses in anesthetized guinea pigs and rabbits, the responses to HCHO were far less in isolated guinea pig auricles and perfused hearts (Langendorff's preparations). The inhibitory responses to HCHO in the isolated auricles and perfused hearts were obtained at concentrations 200-400 times and 4-8 times higher than the blood concentrations attained in anesthetized animals, respectively. The responses in the isolated preparations were not significantly affected by propranolol. The bradycardiac response to the intravenously administered HCHO in anesthetized animals was not significantly affected by atropine or vagotomy, but was markedly attenuated by propranolol, reserpine or surgical denervation of the heart. These results indicate that the direct action of HCHO on the heart plays only a small role in the negative chronotropic response to HCHO in anesthetized animals. Furthermore, the negative chronotropic effect of HCHO in animals seems to be caused mainly by the inhibition of sympathetic nervous activity through the central nervous system.
Tani
T
T
Kanagawa Prefectural Public Health Laboratory, Yokohama, Japan.
Horiguchi
Y
Y
D000758:Anesthesia; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D005557:Formaldehyde / Q000494:pharmacology*; D006168:Guinea Pigs; D006321:Heart / Q000187:drug effects* / Q000294:innervation / Q000502:physiology; D006339:Heart Rate / Q000187:drug effects; D066298:In Vitro Techniques; D008297:Male; D009121:Muscle Denervation; D011433:Propranolol / Q000494:pharmacology; D011817:Rabbits; D014628:Vagotomy
D005557:Formaldehyde; D011433:Propranolol