Effects of Transcutaneous Carbon Dioxide (CO₂) on Hyperglycemia‐Induced Capillary Regression in Skeletal Muscle

Abstract

Hyperglycemia causes microvascular impairment in skeletal muscle of diabetes. Transcutaneous carbon dioxide (CO2) have been shown to increase capillary in skeletal muscle of healthy rats via the increase of angiogenic factor. The purpose of this study was to determine the effects of transcutaneous CO2 on muscle capillary impairment by exposure of hyperglycemia in streptozotocin (STZ)‐treated diabetic rats. Twenty‐four male Wistar rats (220~270g) were divided into control (CON), CO2, STZ and STZ+CO2 groups. STZ (50 mg/kg) was injected into the tail vein of rats. Blood glucose levels above 250 mg/dl after 2 days of the STZ injection confirmed the diabetic state. The lower limbs in rats were shaved and hydrogel was applied afterwards. The CO2 adaptor was attached to the limbs and sealed, and CO2 was administered into the adaptor for 30 min. This treatment was performed 5 days per week for 8 weeks. STZ resulted in capillary regression, indicated by decreases in capillary‐to‐fiber ratio. However, the capillary‐to‐fiber ratio in STZ + CO2 was higher than that in STZ. In addition, the protein expression level of vascular endothelial growth factor (VEGF), which is angiogenic factor, in STZ + CO2 was higher than that in STZ. The protein expression level of thrombospondin‐1 (TSP‐1), which is antiangiogenic factor, in STZ + CO2 was lower than that in STZ. These results indicated that transcutaneous CO2 attenuated the capillary regression via the increase of angiogenic factor and the decrease of antiangiogenic factor.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.