The purpose of this study was to clarify the effects of bicycle ergometer training and prostaglandin E₁ (PGE₁) for patients with intermittent claudication. Subjects were divided into four groups : the medication group (M), the PGE₁ group (P), the exercise group (E) and the PGE₁ and exercise group (PE). The P group was injected with 10μg of PGE₁, the E group performed bicycle ergometer exercise 3 times a week for 6 weeks, and the PE group was injected with PGE₁ and performed exercises. The maximal walking distance (MWD) was evaluated by a treadmill test. Muscle oxygenation level was measured by near-infrared spectroscopy and recovery half time (T_1/2) was calculated. MWD was significantly improved for P (142%), E (216%) and PE (240%) groups. T_1/2 was significantly improved in the E and PE groups. This study indicates that improvement of MWD was a result of development of muscle perfusion in lower limbs and PGE₁ injection may support exercise therapy.

We evaluated regional differences of muscle O₂ dynamics between distal and proximal sites in the vastus lateralis (VL) muscle using near infrared spatial resolved spectroscopy (NIR_SRS). forty-one male subjects performed a 30 W ramp incremental bicycle exercise test until exhaustion. The NIR_SRS probes were attached on each distal and proximal site in the VL. The pulmonary O₂ uptake and heart rate were monitored continuously during the experiment. The TOI at rest was significantly higher in proximal than distal sites (65.0±5.2 vs. 69.7±4.6%, p<0.001). The TOI at exhaustion was also significantly higher in proximal than distal sites (39.5±6.7 vs. 47.5±7.6%, p<0.001). Moreover, a significant correlation was found between VO₂max and the TOI at exhaustion in each proximal and distal site in the VL. Half time reoxygenation, the time to reach a value of half-maximal recovery, was significantly slower in distal sites than proximal sites (27.1±5.6 vs. 25.0±6.1 sec, p<0.01). In conclusion, lower muscle oxygenation at exhaustion in higher VO₂max may be due to enhanced O₂ extraction in high oxidative capacity muscle. In addition, slower reoxygenation and lower muscle deoxygenation at the distal site in the VL may be explained by differences in O₂ supply and/or muscle fiber composition between distal and proximal sites.

The purpose of this study was to determine the age and habitual physical activity on re-oxygenation time in working muscles following maximal cycling exercise (CycEXmax). Twelve sedentary middle-aged (50±6), 13 sedentary elderly (66±3), 13 active middle-aged (53±5), and 20 active elderly (67±5) were evaluated the half re-oxygenation time (T1/2 reoxy) as an index of oxygen delivery, using near-infrared spectroscopy at the vastus lateralis (VL) and lateral head of the gastrocnemius (LG) after CycEXmax. T1/2 reoxys at VL and LG were significantly greater in the elderly subjects than in the middle-aged subjects in both sedentary and active groups. T1/2 reoxys at VL and LG of the active group were smaller than those of the sedentary group, regardless of age. The results of this study suggest that habitual physical activity may attenuate age-related prolongation in T1/2 reoxy in working muscles although ageing delay T1/2 reoxy in working muscles.

The aim of the present study is to clarify the improvement of peripheral muscle oxygen consumption after successful renal transplantation. We investigated change of forearm (brachioradial muscle) muscular oxygen consumption in chronic renal failure children before and after renal transplantation. by using near-infrared spectroscopy.Oxygen consumption of brachioradial muscle was increased significantly after succesful renal transplantation. And half recovery time of brachioradial muscle oxygenation in arterial occlusion and exercise were decreased after renal transplantation.These results suggest that increased muscular blood flow and increased oxidative generation of ATP might contribute to the increased oxygen turn over after renal transplantation.