Effect of prolonged exposure of rats to high carbon dioxide concentrations

The lactate dehydrogenase (LD) isozyme spectrum of heart muscle, the heart rate (HR) and the ECG indices were studied during exposure to high concentrations of carbon dioxide, and the survival rate of rats also was determined in relation to the rate of rise of the carbon dioxide concentration in the atmosphere. Functional changes observed in cardiac activity during exposure to CO₂ in a concentration of 30% for 7.5 h were not accompanied by any disturbance of carbohydrate metabolism of the heart muscle. The most important condition of survival of rats exposed for a long time to an atmosphere with a high (up to 50%) CO₂ concentration is the rate at which the concentration rises.DeceasedInstitute for Medico-Biological Problems, Ministry of Health of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR S. S. Debov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 86, No. 9, pp. 285–287, September, 1978.