Novel device that produces carbon dioxide mist for myocardial infarction treatment in rats

Abstract

Background: Carbon dioxide (CO 2) baths have been used to treat a variety of diseases, but developing an artificial bath of highly concentrated CO 2 is difficult. Here, we tried the efficacy of a novel device instead of a CO 2 bath. Methods and Results: Using a device equipped with double fluid nozzles, CO 2 gas and H 2O were compounded and compressed at 4 barometric pressures. As a result, CO 2 gas was dissolved in H 2O, which contained a few micrometers of CO 2 particles, namely, a CO 2 mist. Wistar rats with myocardial infarction (MI) by ligation of the left coronary artery were percutaneously administered CO 2 mist or CO 2 gas alone or no treatment for 30 min daily. With regard to tissue blood flow during treatment, the group treated with CO 2 mist had significantly increased tissue oxygenated hemoglobin levels and tissue saturation levels, and significantly decreased deoxygenated hemoglobin levels compared with the group treated with CO 2 gas. After 4 weeks treatment, the group treated with CO 2 mist had a significantly improved ejection fraction by echocardiography compared with the untreated group. Interestingly, the group treated with CO 2 mist had significantly increased nitrate concentrations in serum and vascular endothelial growth factor mRNA expression levels in the myocardium compared with the untreated group. Conclusions: Our new mist production device may be potentially useful for the treatment of heart failure caused by MI.