ABSTRACT
In this study, we examined changes in the amplitude of differential digital photoplethysmogram (ΔDPG) and the power spectral changes of EEG at rest during cold water immersion of the contralateral fingers (2°C), and after alcohol intake (0.3 g/kg) in 8 male subjects. This experiment showed that the ΔDPG amplitude decreased at rest and finger blood pressure was increased during the cold water stimulation, but there was no signifincant change in heart rate and EEG power spectrum. On chronological measurements for 30 minutes after alcohol intake, ΔDPG amplitude decreased slightly and finger blood pressure increased. Heart rate also tended to increase, and the alpha 1 power (8.0-9.8 Hz) on EEG gradually increased. The ODPG and finger blood pressure responses to cold water stimulation every 10 minutes was decreased after alcohol intake, whereas heart rate was not affected. However, a decrease in the alphal power after stimulation was revealed. From these results, it may be concluded that during 5-10 s of cold water stimulation, increased skin sympathetic nerve activity was one of the factors that raises blood pressure.
ABSTRACT
A study was designed to determine the effect of cooling down and massage on lower leg volume after heel-raising exercise in men. The subjects were six healthy athletes ranging in age from 18 to 23 years. Lower leg volume was measured at rest and after heel-raising exercise using Lundvall's volumetric method with a water-filled“boot”. Ten minutes of rhythmic heel-raising, performed at 45 times per minute, was monitored continuously using a mech-anograph.<BR>Immediately after the end of exercise, each subject lay in a relaxed supine position and the leg was raised to 45 degrees. A cuff was then attached around the thigh, and the cuff pressure was increased to occlude the leg circulation. The leg volume was then determined in a standing position. After the first measurement of the lower leg, three kinds of treatment were applied for each subject (no treatment, one minute walking : total seven minutes, one minute massage : total five minutes) .<BR>The results obtained were as follows ;<BR>1) The slopes of the recovery curve of lower leg volume were more gentle with no treatment than with cooling down and massage.<BR>2) The time constant (min) obtained from the decreasing curve of lower leg volume after heel-raising exercise was 10.2 for no treatment, 9.4 for cooling down and 6.4 for massage.<BR>3) The total fluid accumulation volume in the lower leg (ml/l lower leg) following heel-raising exercise was 450.9 for no treatment, 288.9 for cooling down and 198.6 for massage.<BR>It is suggested that such a disappearance of fluid accumulation in exercising muscles of the lower leg following cooling down and massage is due to a mechanical pump action against the surrouding local skeletal muscle tissues.
ABSTRACT
The effects of the gravitational potential energy change (GPEC) and the thermal stress on finger microvascular responses were studied by laser Doppler and ultrasonic Doppler flowmetry. Seven healthy male subjects, aged 21 to 31 yrs, participated in the experiment after giving their informed consent. The hand was moved upward (about 60 cm) or downward (about 55 cm) from the heart level to change the vascular transmural pressure of the finger (GPEC) . Sensors of laser Doppler and ultrasonic Doppler flowmeters were attached to the lateral side of the first finger and the skin surface over the radial artery, respectively. Experimental room temperature was maintained at 24°C. Laser Doppler flow (LDF) was decreased at an elevated and lowered arm position. The pulsatile component of LDF, evaluated by the difference between systolic and diastolic LDF, increased when the arm was elevated, but it showed no significant changes when the arm was lowered. Mean blood velocity (MBV) and diastolic blood velocity (DBV) of radial artery decreased when the arm was elevated, whereas the pulsatile blood velocity (PBV), evaluated by the difference between systolic blood velocity (SBV) and DBV, were increased. At the lowered arm position, SBV and PBV decreased significantly, but DBV showed no significant changes. The thermal stress (43°C, 10 min) increased the PBV when the arm was elevated, but the PBV diminished the decreasing rate when the arm was lowered.<BR>These results suggest that the measurements used may be useful for the analysis of arteriolar compliance and microvascular response to the change of transmural pressure pro-duced by the gravitational potential energy change.
ABSTRACT
The effect of changes in vascular transmural pressure upon differential digital plethysmogram (delta DPG) was studied in seven normal subjects. Changes in vascular transmural pressure were produced by the gravitational potential energy change (GPEC method) of an extremity from the heart level. Delta DPG which was characteristic of stability, discrimination and low speed record by modified devices was applied for the experiments including postural, static and dynamic exercises. Room temperature during experiments was kept constant. The Delta DPG-P wave amplitude in maximal elevation of upper and lower extremities (mean±S. D., n) increased to 162.3±33.5% (38) and 176.7±33.4% (12), respectively, and that in maximal lowering of upper and lower extremities decreased to 36.9±10.5% (35) and 37.5±12.6% (15), respectively. These data reveal that the GPEC method may be useful for the determination of arteriolar sensitivity in humans.
ABSTRACT
Evidence of an increased resting blood flow in the tendon against the adjacent muscle was confirmed in the <I>in situ</I> hindlimb preparation of a rabbit anesthetized with urethane. The tendon tissue blood flow was found to be modulated by nervous and mechanical factors. The effect of nervous control was demonstrated by the denervation of the sciatic nerve, which showed a gradual increase in the resting blood flow in the tendon and muscle after being severed. During local muscle exercise, the increase of tendon tissue blood flow observed was minimal in comparison with the adjacent muscle. The tendon surrounding tissue blood flow showed site-dependent characteristics along the longitudinal tendon bundles. Evidence of tendon vascular structure in the rabbit species was confirmed by observing capillaries in cross sectional fascicles and longitudinal and transversal vessels in the paratenon of the Achilles tendon. These results strongly suggest a physiological model of local tissue temperature regulation and fluid dynamics in the biological system.
ABSTRACT
Muscle blood flows by means of hydrogen gas clearance method were measured on hindlimb muscles in sedentary control (nE) and exercised (Ex) spontaneously hypertensive rats (SHR) . SHR and Wistar control rats (WCR) were divided into two groups at 7 weeks of age ; SHRnE, SHREx and WCRnE, WCREx. Exercised rats were bred in cages with rotating wheels capable of running voluntarily for additional 10 weeks. Body weights of exercised groups in both SHR and WCR were lower than those of sedentary controls, whereas food consumptions of exercised rats tended to be more than those of sedentary controls. Ratios of the heart weight to the body weight of SHR and WCR were higher in exercised groups. There was no significant difference in systolic blood pressure obtained by an indirect tail-cuff method between exercised and sedentary control SHR. Resting blood flows in both M. Gastrocnemius and M. Soleus showed lower values in SHR groups than those in WCR groups. Postexercise blood flows at 1 Hz and 5 Hz were higher in exercised groups. These results suggest that peripheral adaptability of blood flow control to the exercise is still normal on hindlimb muscles in SHR.
ABSTRACT
In addition to the histological study of tendon blood circulation, high level of resting blood flows have been functionally observed in the in-vivo tendon tissue preparation. Interest has been directed to investigate the phenomenon from the measurement of tendon tissue Po2 changes which may indicate the activity of capillary blood flow. Simultaneous measurements were done in tendon synovial fluid, tendon and muscle tissues of the 15 rabbit hindlimbs, in conditions of hypoxia and hyperoxia. Continuous measurements of tissue Po<SUB>2</SUB> were performed by polarographic method using a pair of the wire platinum electrode (80μm in diameter) with polymer membrane to the indifferent silver electrode. Average Po<SUB>2</SUB> of tendon synovial fluid, tendon fiber and muscle tissues at rest (mean±SD, n) were 37.36±24.32 (10), 30.96±14.72 (10) and 19.54±8.05 (8), respectively. These data increased gradually to the maximal level of 45.46±27.46 (10), 39.23±16.23 (10) and 25.96±9.77 (8) after cutting of sciatic nerve. Reactive hyperemia-like Po<SUB>2</SUB> increase immediately after release of femoral arterial occlusion was observed neither in tendon synovial fluid nor in tendon tissue. There was no significant difference between each other of tissues in the process of Po<SUB>2</SUB> increase during oxygen intake and the decrease after cessation of oxygen flushing. During exercise, a marked decrease of Po2 was obtained in muscle, but not in tendon synovial fluid.<BR>These data indicate that high level of Po<SUB>2</SUB> in tendon and the surrounding tissuse may have some oxygen supply channels including segmental blood supply system with a short length of and/or a large size of capillary.