ABSTRACT
The purpose of this study was to investigate the differences and effects of positional loading (arm position change) and image loading in Budo (martial arts) competitors, mainly kendo (Japanese fencing) masters. The microcirculatory responses were measured by differential digital photoplethys-mography (ΔDPG) using the characteristics of Budo mental attitude, experience and skill as para-meters.<BR>The subjects were 7 kendo masters of the fifth grade or higher with mean experience of 29 years, 7 kendo athletes, 7 kyudo (Japanese archery) athletes, 5 karate athletes in university sports clubs and 9 middle-aged controls. Positional loading induced myogenic responses and image loading for examining sympathetic effects via the central nervous system on peripheral circulation were mea-sured in the subjects at rest in a sitting position. The following results were obtained<BR>The increase in the . ΔPG-P wave height in response to positional loading was markedly larger in the kendo masters. In particular, the increase when raising the right arm was significantly higher in the kendo masters than in the kyudo and karate athletes (P<0.05) . The decrease in the ΔDPG-P wave height when lowering the right arm was smallest in the kendo masters. There were differences in the peripheral vascular responses between kinds of Budo and levels of skill, which were induced by differences at the time of arm raising.<BR>The DPG-P wave height was significantly lower during stress imaging than before loading in all subjects. The effect of stress imaging was smallest in the kendo masters, and markedly large in the kyudo athletes (P<0.05) . During relaxation imaging, an increase in the ΔDPG-P wave height was observed in the kendo masters alone, and the occurrence of vascular dilation was confirmed.<BR>These results suggest that arteriolar responses of kendo masters are flexible and stable despite their long training period ; and the control and regulation of muscle vascular tone is well-maintained via the central nerve-sympathetic and myogenic coupling.
ABSTRACT
The purpose of this study was to determine the change in elbow flexor isometric torque at different phases of the menstrual cycle in humans. The subjects were six eumenorrheic females (age 22.0±3.5yr ; height 156.5±3.3cm ; body mass 50.2±4.9 kg) . The serum luteinizing hormone (LH), estradiol and progesterone levels, maximal voluntary contraction (MVC), integrated electromyographic activity (iEMG), interpolated twitch torque, evoked contractile properties, anthropometric parameters and Profile of Mood States (POMS) were measured at three different phases of the menstrual cycle, i. e., the menstrual, ovulatory and luteal phases. The MVC was significantly higher in the ovulatory phase than in the menstrual and luteal phases (P<0.05) . The iEMG, calculated voluntary activation and anthropometric parameters did not change significantly over the menstrual cycle. The MVC/iEMG ratio (electromechanical efficiency) and the evoked peak torque were also significantly higher in the ovulatory phase than in the menstrual and luteal phases (P<0.05, P<0.01) . In the menstrual phase, the fatigue and anger subscale score of POMS were significantly higher (P<0.05) and the vigor subscale score was significantly lower than in the other phases (P<0.05) . These results indicate that the variation in MVC observed over the menstrual cycle may be related to the intrinsic contractile properties rather than neural or psychological factors.
ABSTRACT
The purpose of this study was to investigate the effect of the sleep deprivation for central information processing. Therefore we examined the changes in the amplitude and the latency of P300 event-related potentials (ERPs) before and after sleep deprivation in eight subjects. In addition to P300, we examined the power spectral changes of the EEG and the R-R intervals at rest before ERP measurements. The subjects performed an auditory target discrimination task and were instructed to keep mental count of each target stimulus. Then 2000 Hz tones (target) and 1000 Hz tones (nontarget) were randomly presented with probabilities of 0.2 and 0.8.<BR>P300 latency at Fz, Cz, C3 and C4 was significantly prolonged after sleep deprivation (p<0.05) . P300 amplitude at Cz after sleep deprivation was significantly smaller than before sleep deprivation (p<0.05) . Alpha 1 power (8-10 Hz) at Cz on EEG was significantly decreased after sleep deprivation, but no other bands changed on EEG. The R-R interval was also significantly extended after sleep deprivation. We concluded that both central information processing and the autonomic nervous system may be influenced by sleep deprivation.
ABSTRACT
Event-related potentials (ERPs) were recorded from 9 normal subjects engaged in a somatosensory target discrimination task. Subjects were instructed (1) to keep a mental count of each target or (2) to rotate a grip in the direction of abduction after each target stimulus using the right hand. Target stimuli were electrical pulses delivered randomly through ring electrodes to the left second digit with probabilities of 0.2, and nontarget stimuli were delivered to the left fifth digit with probabilities of 0.8.<BR>P 100 was prominent in somatosensory tasks, and had a widespread distribution on the scalp without having any relation to kinds of tasks, therefore, P 100 reflects the sensation of somatosensory stimulation. N 140 was largest at Fz in both counting and movement tasks, so our result supported the hypothesis that N 140 is generated in the frontal lobes regions. Moreover, N 140 latency was shorter during movement than during counting. These results indicate that N 140 is related to carrying out movement. P 300 was largest at Cz during counting, and largest at Pz and C4' during movement. These results also indicate that P 300 may have multiple intracerebral generators since P300 origin differs based on the kind of tasks or stimuli. In addition, the appearance of P300 after nontarget stimuli indicates that P 300 reflects a non-selective postdecision closure of cognitive activity. In conclusion, each component of ERPs may have a specific origin and specific characteristics.
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.
ABSTRACT
Blood flow in relationship to muscular contraction were studied in hindlimb of rabbits anesthetized with urethane and electricity.<BR>Exercise hyperemia (EH), postexercise hyperemia (PEH) and hematocrit (Hct) were measured with time intervals. Under a blood pressure of 100/70 mmHg by urethan anesthesia, EH with stimulation of 5 to 10 Hz was exponentially increased to a 2-3 times more than the control level. But, EH produced by stimulation of 20 to 50 Hz decreased from the start to the first 20 sec of exercise, then increased gradually to a peak within 60 sec after exercise. Recovery time in PEH was prolonged as the intensity of the stimulation increased ; about 4 min by 5 Hz, 6-7 min by 10 Hz, and 8-13 min by 20-50 Hz. On the other hand, under a blood pressure of 150/100 mmHg by electroanesthesia, a rapid increase in EH was observed, and a shorter recovery time in PEH was obtained with an equal stimulation ; about 2 min by 5 Hz, and 4 min by 20 Hz.<BR>An increase in Hct occurred at the first 15 to 20 sec of exercise, and in strenuous muscle contraction it was approximately 3% higher than the resting level. In PEH, Hct decreased gradually as the degree of hyperemia fell.<BR>Muscle blood flow and Hct increase in response to the muscular activity evoked. The data suggest that these changes depend on the complex mechanism of arteriolar dilatation, capillary bed enlargement, an increase of capillary permeability and water shift.
ABSTRACT
1) A method of recording electrocardiograms during the performance of active hands-tanding exercise, passive handstanding, upright standing and upright standing with load were described. Data obtained from 19 normal healthy subjects were analyzed.<BR>2) For the analysis of exercise electrocardiogram, the most important is to grasp the characteristics of ECGs of the individual subjects. The control examination was made on the tracings of electrocardiographic changes in wave patterns, amplitudes, time intervals and electric heart axis due to four different lying postures (supine, prone, leftside, and right side) and to the respiratory movement by standard limb lead and special lead (MII) . Lead MII (modified standard lead II: Manubrium sterni↔left leg) was used throughout the expe-riments. The paper speed was 50mm per second.<BR>3) During active handstanding exercise, the time interval (sec) shortened quickly in T-P and slowly in P-Q and Q-T intervals. A slight decrease in the amplitude of the T-wave were observed.<BR>4) During passive handstanding prolongation of R-R interval was observed. At the angle of ∠70° shifted from the horizontal prolongation of R-R (T-P) interval atarted, but no change in P-Q and Q-T intervals occurred. T-wave showed slight increasse in passive handstan-ding immediately after body shift, but no markable change appeared during the period of loading.<BR>5) During upright standing and upright standing with load shortening of R-R interval were observed, but no change in P-Q and Q-T intervals occurred. Amplitude of each wave did not change during the period of loading.<BR>6) It is suggested that during active handstanding increase in sympathetic activity accelerates the cardiac rate, on the other hand, increase in parasympathetic activity mediated through the buffer nerve system (sinus caroticus, aortic nerve) decelerates it during passive handstanding. It appears to be general that autonomic nervous system plays an important role in the static exercise.