CO2-ENRICHED WATER BATH AS A NOVEL THERAPY FOR PERIPHERAL VASCULAR DISEASE



Narajan Dhalla, Ph.D., M.D. Hon., ICS, St. Boniface Hospital Research, University of Manitoba, Canada

Peripheral artery disease (PAD) is a major health problem whereby narrowed arteries reduce blood flow to the ischemic limbs. We investigated the effects of CO2-enriched water bath (CEWB) therapy on blood flow in the ischemic hind limb. The femoral artery was occluded in rats to induce PAD and the animals were treated with or without CEWB at 37°C for 4 weeks (20 min/day; 5 days/week) starting one week after artery occlusion. CEWB was prepared by using Carbothera (Mitsubishi Rayon Engineering, Tokyo). Peaks, mean and minimal blood flows, as measured by Pulse Wave Doppler Ultrasound technique, were not detected in the untreated ischemic hind limb of animals due to arterial ligation. However, blood flow values were about 50% of the control upon treatment with CEWB; 67% of the ligated animals showed positive blood flow by CO2 treatment. Morphological examination of the treated ischemic skeletal muscle revealed a 3-fold increase in small artery numbers indicating the formation of new blood vessels. Although plasma triglycerides decreased and plasma NO concentration increased in ischemic animals, CEWB treatment produced no effects on these parameters. It is suggested that beneficial action of CO2 therapy on blood flow to hind limb may be due to the development of angiogenesis in the ischemic skeletal muscle. (Infrastructure support for this study was provided by the St. Boniface Hospital Foundation)