Percutaneous Carbon Dioxide Gas Mist Ameliorates Cardiac Remodeling after Myocardial Infarction in Rats ＊ : p<0.05 (ms1/2) T. Yamazaki, Y. Nakamura, Y. Izumi, A. Hanatani, K. Shimada, T. Muro, M. Yoshiyama – Osaka City University, Osaka, Japan <Echocardiography> Background Results <Vasodilatation effect of CO2 gas mist for microvessels > Pre 10 min Post 10 min Re try 5 min Carbon dioxide (CO2) bathing has been used to treat some cardiac diseases. P<0.05 P<0.05 P<0.05 * * The effect of CO2-enriched water on cutaneous circulation depends primarily on the vasodilatation effects elicited by the CO2 that diffuses into the subcutaneous tissue through the skin layers. * * * * * (Ito T et al. J Invest Dermatol. 1989;93:259-262) (Schnizer W et al. Int J Microcirc Clin Exp. 1985;4:343-350) Immersion of an ischemic hind limb into CO2-enriched water caused a nitric oxide (NO)-dependent increase in collateral blood perfusion. (Irie H et al. Circulation. 2005;111:1523-1529.) * * P<0.05 However, the effect of CO2 gas mist has not been examined. P<0.05 * * Purpose <Oxygenated and Deoxygenated Hemoglobin> <Δ Tissue pH> * We investigated 1) whether percutaneous CO2 gas mist had useful effects compared with CO2 gas, 2) whether percutaneous CO2 gas mist prevented cardiac remodeling after myocardial infarction (MI) in rats. * * * * CO2 mist LVEDV : Left Ventricular End-Diastolic Volume, LVESV : Left Ventricular End-Systolic Volume, LVEF : Left Ventricular Ejection Fraction * p<0.05 vs NM <mRNA expressions (pRT-PCR) > <Serum Concentrations> Methods ＜MI production＞ MI was induced by ligation of the coronary artery in 8 wks old male Wistar rats. ＜Study Protocol＞ ( NM : no CO2 gas mist therapy ) ( M+L : 100% CO2 gas mist therapy 30min/day + L-NAME 10 mg/kg/day) ( CM : 100% CO2 gas mist therapy 30 min/day ) ( CG : 100% CO2 gas therapy 30 min/day ) ( C : Control ) Sacrifice at 4 weeks Sham operation MI production CO2 gas P<0.05 P<0.05 * * (min) (min) (min) * p<0.05 vs CO2 gas <Hemodynamics> * P<0.05 * p<0.05 vs NM For normalization, transcript levels were compared to GAPDH. * p<0.05 vs NM Summary CM group had significantly increased oxygenated hemoglobin levels and significantly decreased deoxygenated hemoglobin levels and subcutaneous tissue pH, compared with CG group. CM group had a significantly increased LVEF compared with NM group. The CM group had significantly increased NO3- concentrations and cardiac VEGF mRNA expression compared with NM group. These improvements were significantly abolished with L-NAME treatment. Our present study shows for the first time that percutaneous CO2 gas mist can prevent cardiac remodeling after MI. ( a nitric oxide synthase inhibitor) CO2 gas H2O CO2 gas mist CO2 + H2O * * * Conclusion The CO2 gas mist was generated using a dry mist production unit. (Advance Biotron Co., Ltd., Tokyo, Japan) Percutaneous CO2 gas mist may be a potentially useful therapy for heart failure due to MI. HR : Heart Rate, sBP : systolic Blood Pressure, dBP : diastolic Blood Pressure, HW : Heart Weight * p<0.05 vs NM