Division of Cardiology, Taipei Veterans General Hospital, Taipei, Taiwan.
Cardiovasc Diabetol. 2012 Aug 15;11:99. doi: 10.1186/1475-2840-11-99.
Far infra-red (IFR) therapy was shown to exert beneficial effects in cardiovascular system, but effects of IFR on endothelial progenitor cell (EPC) and EPC-related vasculogenesis remain unclear. We hypothesized that IFR radiation can restore blood flow recovery in ischemic hindlimb in diabetic mice by enhancement of EPCs functions and homing process.
Starting at 4 weeks after the onset of diabetes, unilateral hindlimb ischemia was induced in streptozotocin (STZ)-induced diabetic mice, which were divided into control and IFR therapy groups (n = 6 per group). The latter mice were placed in an IFR dry sauna at 34°C for 30 min once per day for 5 weeks.
Doppler perfusion imaging demonstrated that the ischemic limb/normal side blood perfusion ratio in the thermal therapy group was significantly increased beyond that in controls, and significantly greater capillary density was seen in the IFR therapy group. Flow cytometry analysis showed impaired EPCs (Sca-1(+)/Flk-1(+)) mobilization after ischemia surgery in diabetic mice with or without IFR therapy (n = 6 per group). However, as compared to those in the control group, bone marrow-derived EPCs differentiated into endothelial cells defined as GFP(+)/CD31(+) double-positive cells were significantly increased in ischemic tissue around the vessels in diabetic mice that received IFR radiation. In in-vitro studies, cultured EPCs treated with IFR radiation markedly augmented high glucose-impaired EPC functions, inhibited high glucose-induced EPC senescence and reduced H(2)O(2) production. Nude mice received human EPCs treated with IFR in high glucose medium showed a significant improvement in blood flow recovery in ischemic limb compared to those without IFR therapy. IFR therapy promoted blood flow recovery and new vessel formation in STZ-induced diabetic mice.
Administration of IFR therapy promoted collateral flow recovery and new vessel formation in STZ-induced diabetic mice, and these beneficial effects may derive from enhancement of EPC functions and homing process.
远红外（IFR）疗法已被证明对心血管系统有有益的影响，但 IFR 对内皮祖细胞（EPC）和 EPC 相关血管生成的影响尚不清楚。我们假设 IFR 辐射可以通过增强 EPC 功能和归巢过程来恢复糖尿病小鼠缺血后肢的血流恢复。
在链脲佐菌素（STZ）诱导的糖尿病发生后 4 周，诱导单侧后肢缺血，将糖尿病小鼠分为对照组和 IFR 治疗组（每组 n = 6）。后者每天在 34°C 的 IFR 干蒸浴室中放置 30 分钟，共 5 周。
多普勒灌注成像显示，热疗组缺血肢体/正常侧血流灌注比在对照组明显增加，并且在 IFR 治疗组中观察到明显更大的毛细血管密度。流式细胞术分析显示，无论是否接受 IFR 治疗，糖尿病小鼠缺血手术后 EPC（Sca-1（+）/Flk-1（+））动员受损（每组 n = 6）。然而，与对照组相比，接受 IFR 辐射的糖尿病小鼠血管周围缺血组织中，骨髓来源的 EPC 分化为内皮细胞（定义为 GFP（+）/CD31（+）双阳性细胞）明显增加。在体外研究中，用 IFR 辐射处理的培养 EPC 显著增强了高糖损害的 EPC 功能，抑制了高糖诱导的 EPC 衰老，减少了 H（2）O（2）的产生。接受 IFR 辐射处理的高糖培养基中的人 EPC 的裸鼠显示出缺血后肢血流恢复的显著改善，与未接受 IFR 治疗的裸鼠相比。IFR 治疗促进了 STZ 诱导的糖尿病小鼠的侧支血流恢复和新血管形成。
IFR 治疗促进了 STZ 诱导的糖尿病小鼠的侧支血流恢复和新血管形成，这些有益作用可能来自于增强 EPC 功能和归巢过程。
