Carbon Dioxide Effects on Myocardial Contractility. ∗

Abstract

Summary

Rat myocardial preparations were stimulated to contract at one per second in an oxygenated Ringer's solution. The effects of 0%, 2% and 5% CO₂ on the magnitude of the isometric developed tension were studied during a 3-hour experimental period. It was noted that muscles aerated with a gas mixture containing 2% CO₂ revealed not only a constant developed tension but also a small variation in contractile response during the experiments. The detrimental effects of the other percentages of CO₂ on the developed tension were not immediately evident.