Relationship between reduced lower abdominal blood flows and heart rate in recovery following cycling exercise.

AIM: To examine the blood flow (BF) response in the lower abdomen (LAB) in recovery following upright cycling exercise at three levels of relative maximum pulmonary oxygen consumption (VO(2max)) and the relationship of BF(LAB) to heart rate (HR) and target intensity. METHODS: For 11 healthy subjects, BF (Doppler ultrasound) in the upper abdominal aorta (Ao) above the coeliac trunk and in the right femoral artery (RFA) was measured repeatedly for 720 s after the end of cycling exercises at target intensities of 30%, 50% and 85% VO(2max), respectively. Blood flow in the lower abdomen (BF(LAB)) can be measured by subtracting bilateral BF(FAs) (≈twofolds of BF(RFA)) from BF(Ao). Change in BF(LAB) (or BF(LAB) volume) at any point was evaluated by difference between change in BF(Ao) and in BF(FAs). Heart rate and blood pressure were also measured. RESULTS: At 85% VO(2max), significant reduction in BF(LAB) by approx. 89% was shown at 90 s and remained until 360 s. At 50% VO(2max), reduction in BF(LAB) by approx. 33% was found at 90 s although it returned to pre-exercise value at 120 s. On the contrary at 30% VO(2max), BF(LAB) showed a light increase (<20%) below 70 bpm of HR. There was a close negative relationship (P < 0.05) between change in BF(LAB) and recovery HR, as well as between change in BF(LAB) volume and both recovery HR and % VO(2max). CONCLUSION: This study suggests that the lower abdominal BF in recovery may be influenced by sympathetic-vagus control, and dynamics of BF(LAB) may be closely related to the level of relative exercise intensities.

Vitamin E supplementation and endurance exercise: are there benefits?

It has been widely noted that vitamin E shows numerous beneficial effects through and beyond its antioxidative properties; consequently, vitamin E is expected to prevent degenerative diseases. In the field of sports medicine, many studies dealing with vitamin E have been conducted originally from the point of view of its effects on physical performance. Although some earlier studies indicated that vitamin E supplementation could improve physical performance, defects in the study design or statistical analysis were pointed out at a later time. The majority of subsequent well controlled studies have reported no significant effect on physical performance from vitamin E supplementation. Recent studies suggest that endurance exercise may promote free radical generation in the body, and vitamin E may play an important role in preventing the free radical damage associated with endurance exercise. Although there is evidence of free radical involvement in exercise-induced muscle injury, vitamin E supplementation might not be expected to prevent muscle damage caused by exercise in humans without a vitamin E deficiency. Since it is still unclear whether exercise induces lipid peroxidation in the human body, the beneficial effect of vitamin E supplementation on exercise-induced lipid peroxidation has not yet been established. However, it is proposed that as a result of exercise vitamin E may be mobilised from store tissues and redistributed in the body to prevent oxidative damage. Therefore, we are convinced that vitamin E contributes to preventing exercise-induced lipid peroxidation. It has also been indicated that strenuous endurance exercise may enhance the production of oxidised low density lipoprotein (LDL), which plays a key role in the initiation and progression of atherosclerosis. It is also suggested that this enhanced production of oxidised LDL could be reduced if a higher vitamin E status is maintained. Supplementation with 100 to 200mg of vitamin E daily can be recommended for all endurance athletes to prevent exercise-induced oxidative damage and to reap the full health benefits of exercise.

Reduced blood flow in abdominal viscera measured by Doppler ultrasound during one-legged knee extension.

The redistribution of blood flow (BF) in the abdominal viscera during right-legged knee extension-flexion exercise at very low intensity [peak heart rate (HR), 76 beats/min] was examined by using Doppler ultrasound. While sitting, subjects performed a right-legged knee extension-flexion exercise every 6 s for 20 min. BF was measured in the upper abdominal aorta (Ao), right common femoral artery (RCFA), and left common femoral artery (LCFA). Visceral BF (BFVis) was determined by the equation [BFAo - (BFRCFA + BFLCFA)]. A comparison with the change in BF (DeltaBF) preexercise showed a greater increase in DeltaBFRCFA than in DeltaBFAo during exercise. This resulted in a reduction of BFVis to 56% of its preexercise value or a decrease in flow by 1,147 +/- 293 (+/-SE) ml/min at the peak workload. Oxygen consumption correlated positively with DeltaBFAo, DeltaBFRCFA, and DeltaBFLCFA but inversely with DeltaBFVis during exercise and recovery. Furthermore, BFVis (% of preexercise value) correlated inversely with both an increase in HR (r = -0.89), and percent peak oxygen consumption (r = -0.99). This study demonstrated that, even during very-low-intensity exercise (HR <90 beats/min), there was a significant shift in BF from the viscera to the exercising muscles.

Differences in HDL cholesterol concentrations in Japanese, American, and Australian children.

BACKGROUND: Mortality from coronary heart disease is relatively low in Japan compared with other developed countries and has remained low despite an increasing standard of living and an apparent increase in mean plasma cholesterol concentration in adults over the past three decades. Important differences in childhood plasma lipoprotein profile might contribute to some of the difference in coronary heart disease mortality seen between Japan and both Australia and North America. METHODS AND RESULTS: Plasma HDL cholesterol and total cholesterol were surveyed in representative populations of schoolchildren in Australia, Japan, and Bogalusa, La. The mean concentration of plasma HDL cholesterol (but not total cholesterol) was higher for Japanese schoolchildren than for Australian or US schoolchildren (P<.001). In addition, the difference in plasma HDL cholesterol between the ages of 8 to 10 years and 12 to 15 years was much greater for Australian (boys, 15.2%; girls, 2.6%) and US (boys, 9.1%; girls, 2.7%) children than for their Japanese counterparts (boys, 4.2%; girls, 1.9%). An examination of potential explanatory factors revealed little difference in body mass index between samples, higher physical activity levels for the Japanese compared with the Australians, and substantial differences in dietary intake between Japanese and Australian schoolchildren. CONCLUSIONS: The relatively high ratio of plasma HDL cholesterol to total cholesterol in Japanese schoolchildren and the relatively small negative difference of plasma HDL cholesterol with age may help to explain why the coronary heart disease mortality rate in Japan is low compared with that in other developed countries.

Noninvasive measures of oxidative metabolism on working human muscles by near-infrared spectroscopy.

The purpose of this study was to determine whether the initial rate of hemoglobin and myoglobin deoxygenation during immediate postexercise ischemia, a reflection of muscle O2 consumption (VO2mus), can be a quantitative measure of muscle oxidative metabolism. The finger flexor muscles of five healthy men (aged 25-31 yr) were monitored by 31P-magnetic resonance spectroscopy for changes in phosphocreatine (PCr), Pi, and pH. Tests were conducted during 15 min of cuff ischemia and during 5 min of submaximal isotonic grip exercise at 10, 20, 30, and 40% of maximal voluntary contraction, one contraction every 4 s. The VO2mus changes were also monitored by near-infrared spectroscopy with continuous wave. The VO2mus during exercise was expressed relative to the resting value. The resting metabolic rate, calculated from the PCr breakdown rate after complete O2 depletion, was 0.0010 (SD) mM ATP/s. During submaximal exercise (pH > 6.9), the VO2mus increased with a rise in intensity (0.036 +/- 0.011, 0.054 +/- 0.016, 0.062 +/- 0.012, and 0.067 +/- 0.020 mM ATP/s during 10, 20, 30, and 40% maximal voluntary contraction, respectively) and showed significant correlation with changes in both calculated ADP and PCr values (r2 = 0.98 and r2 = 0.99, respectively). In conclusion, because of the significant correlation with regulatory metabolites (ADP and PCr) of oxidative phosphorylation, O2 decline rate in immediate postexercise ischemia determined by near-infrared spectroscopy with continuous wave can be utilized for the quantitative evaluation of localized muscle oxidative metabolism.

Relationships between exhaustive mood state and changes in stress hormones following an ultraendurance race.

To investigate how the pituitary-adrenal and sympathetic nervous hormones change in psychologically exhaustive states following an ultraendurance race, the Profile of Mood States (POMS), plasma ACTH, beta-endorphin, adrenaline, noradrenaline, and serum cortisol were measured in 29 male athletes two days before, immediately after, and one day after a triathlon. Psychological exhaustion was defined as possessing low POMS vigour and high fatigue immediately post-race. Eleven subjects met the criteria for the exhaustive group, and another ten were placed in the vigour group, which possessed high vigour regardless of fatigue score and the remaining eight subjects were excluded from analysis because they did not satisfy experimental protocol. Student's t-tests revealed no significant group differences in age, race time, pre-race POMS and hormone values. Immediately post-race, serum cortisol and plasma adrenaline did not differ between groups. However, significantly lower levels of plasma beta-endorphin (p = 0.03) and noradrenaline (p = 0.05), and relatively lower levels of plasma ACTH (P = 0.08) immediately post-race were observed in the exhaustive group when compared with the vigour group. We conclude that pituitary and sympathetic nervous hormone reactivity is attenuated following ultraendurance race in athletes showing psychological exhaustion and this is independent of race performance.

Development of public policy and physical activity initiatives internationally.

Epidemiological, pathological, clinical, and experimental studies over the past 40 years convincingly show that physical inactivity and low physical fitness contribute substantially to the major chronic diseases prevalent in industrialised societies. Several industrialised countries around the world report increases in physical activity participation among adults in recent years, but the prevalence of inactivity remains high. These increases in voluntary exercise are at least partially offset by decreasing daily energy demands due to increased mechanisation at home, at work and during leisure-time. In developing countries, physical inactivity is becoming a prevalent lifestyle due to rapid social and economic changes. Clinical interventions and mass appeals to be more physically active are limited in effectiveness against the background of increasingly sedentary lifestyles. Exercise scientists and public health officials need to turn attention to public policy and legislative initiatives to restructure physical and social environments to encourage more physical activity and discourage sedentary habits.

[Avellis syndrome in systemic rheumatoid vasculitis].

A 74-year-old man presented sudden onset hoarseness and dysphagia. Two months before this event, he had developed arthralgia of the shoulders, elbows, hands and foot and pleuritis which had been alleviated by a treatment with prednisolone. On admission, the patient could not phonate nor swallow at all. His soft palate was elevated at the right side. The uvula moved left when the patient tried to speak. Laryngoscopic examination revealed the paralysis of right vocal cord. The erythrocyte sedimentation rate (79mm/1h), C-reactive protein (5.3mg/dl), rheumatoid factor (310 IU/ml) and Clq-binding immune complex (4.5 micrograms/ml) were elevated. Hepatitis C virus antibody titer was more than 10.8 IU/l. Anti-nuclear antibody was 1:20 (normal < 1:20) and anti-neutrophil cytoplasmic antibody (p-ANCA) was positive. Blood study also revealed the evidences of hemolytic anemia and hypoproteinemia. Hepatitis B virus markers, cryoglobulin, anti-ds DNA, anti-Sm, anti-RNP, anti-SS-A, anti-SS-B antibodies were negative. Magnetic resonance imaging of the brainstem was normal. A sural nerve biopsy revealed patchy demyelination of the fascicles. The teasing of nerve fibers showed segmental demyelination. Chest X-ray showed the interstitial pneumonia and pleuritis in the right lower lung. Otological examination revealed the bilateral secretory otitis media. A treatment with high dose prednisolone, ciclosporin and cyclophosphamide was partially effective. However we could not continue these medication because of the induction of liver damage. The patient died of multi-organ failure around a year after the emergence of aphonia and dysphagia. The autopsy specimen of the right vagus nerve showed the similar patchy damage of nerve fibers as was observed in the biopsied sural nerve. The present case was diagnosed as systemic rheumatoid vasculitis. The syndrome of aphonia and dysphagia due to paralysis of the unilateral soft palate and vocal cord is called Avellis syndrome. This syndrome has been reported mainly in relation with the infarction of lateral medulla. The present case shows that Avellis syndrome can be produced by mononeuritis of the vagus nerve.

Collagenous deposits on explanted intraocular lenses.

An immunohistochemical study of type I collagen in deposits on the surface of two intraocular lenses (IOLs) explanted from human eyes was conducted. Type I collagen-immunoreactive proteinaceous deposits with cells were found around the haptics of an iris-supported IOL. A few such deposits and what appeared to be macrophages were observed on the optic. A few cells (presumably macrophages and giant cells) were observed on a posterior chamber IOL, whereas proteinaceous deposits that reacted positively to the antibody were not identified. Type I collagen-immunoreactive deposits on the iris-supported IOL were thought to be the products of fibroblastic cells, originating from iris tissue, that attached directly to the haptics and helped stabilize the implant.

Immunohistochemical study of deposits on intraocular lenses explanted from human eyes.

Immunohistochemical studies of deposits were carried out on two intraocular lenses (IOLs) explanted from human eyes. One anterior chamber intraocular lens (AC-IOL) was studied using a monoclonal anti-human type I collagen-peptide antibody (C-Ab). One posterior chamber intraocular lens (PC-IOL) was studied using a monoclonal anti-human vimentin antibody (V-Ab). Most of the cells on the AC-IOL contained many melanin granules in the cytoplasm and were thought to be macrophages. They did not show any immunoreactivity to C-Ab. Some spindle-shaped cells and fibrous deposits at the margin of the lens optics showed immunoreactivity to the antibody. These cells were thought to be fibroblasts migrating from the tissue around the IOL, such as the iris. On the PC-IOL, many mononuclear cells and multinucleated giant cells were observed. These cells showed immunoreactivity to vimentin and contained immunostained fibers which were intermediate filaments. They were thought to be either of mesodermal origin or derived from the lens epithelium.

[Left ventricular function after prolonged exercise].

To determine whether depressed left ventricular (LV) contractile function can occur after exhaustive exercise, echocardiographic studies were performed in eleven athletes before, at the finish (9 minutes) and during recovery (15 hour) after the Biwa Lake Ironman Triathlon (3.2 km Swim, 161 km Bike, 32 km Run). Before racing and during recovery, the studies were performed both at rest and after brief exercise (10-15 minutes). Heart rates after brief exercise were comparable to those attained after racing. Digitized M mode echocardiographic data as to wall thickness, cavity dimension, fractional shortening (FS) and peak circumferential shortening (maxVcf) were obtained. When we compared race finish to pre-race brief exercise, the LV end-diastolic dimension (EDD) was reduced (46 +/- 7 vs 47 +/- 6 mm, less than 0.05) and FS declined (33 +/- 5 vs 39 +/- 6%, p less than 0.05). In spite of reduced wall stress, maxVcf decreased. Individual percent reductions in FS were not correlated with decrease in EDD, but correlated with increases in EDS. Although a persistent reduction in cavity size was observed during recovery, FS and maxVcf returned toward the baseline. The results suggest that prolonged strenuous exercise may result in impaired LV function in part because of a reversible depression in the contractile state.

Effects of adenosine and pertussis toxin on lipolysis in adipocytes from exercise-trained male rats.

The sensitivity and responsiveness of adipocyte lipolysis to adenosine and pertussis toxin were studied in exercise-trained male rats. Exercise training (9 weeks of treadmill running) significantly increased lipolytic response of adipocytes to noradrenaline (NA). Addition of adenosine deaminase (ADA) to reaction mixture effectively enhanced NA-stimulated lipolysis in adipocytes from both conditioned rats. However, under these conditions, the difference due to exercise training was still evident, although the difference was less pronounced. The inhibition curves of the R-site adenosine analogue N6-phenylisopropyladenosine (PIA) against "basal" (lipolysis in the presence of ADA) and NA-stimulated lipolysis were almost comparable between two groups. Only a small (approx. 2-fold) increase in IC50 of adipocyte lipolysis was observed in each inhibition curve in exercise-trained rats. Within 120 min of addition of pertussis toxin to adipocytes from control rats, "basal" lipolysis was significantly increased as compared to "basal" lipolysis in the absence of toxin at the same point. Similarly, pertussis toxin significantly increased "basal" lipolysis in exercise-trained adipocytes. However these were relatively sensitive to pertussis toxin, since significant effect of toxin was seen within 60 min. An addition of NA (0.1 uM) to the medium in the presence of ADA and toxin significantly increased adipocyte lipolysis in both conditioned rats. Again, under these conditions, we observed that the maximal rate of lipolysis of adipocytes from exercise-trained rats was increased as compared to control rats. These results suggest that the decreased input through the inhibitory pathway in lipolytic cascade may be not rate limiting for the amplified lipolytic responsiveness of adipocytes to hormonal stimuli in exercise-trained rats.

Iron Status in Ultraendurance Triathletes.

In brief: Using several hematologic indexes, researchers examined the iron status of 50 ultraendurance athletes participating in the 1988 Ironman Triathlon in Hawaii. Fifteen (30%) of the 50 triathletes had at least one suboptimal iron index: Two exhibited stage 2 iron deficiency in the presence of normal hemoglobin levels; eight had normal ferritin levels but subnormal levels of transferrin saturation and iron; three had abnormal levels of total iron-binding capacity; and two had low hemoglobin levels with all other iron indices normal, which indicated dilutional anemia. These data suggest that several indexes need to be examined when assessing the iron status of triathletes and that unusual values do not necessarily reflect actual iron deficiency.

Entrapment of phenylalanine ammonia-lyase in silk fibroin for protection from proteolytic attack.

Phenylalanine ammonia-lyase was entrapped in silk fibroin. The entrapped enzyme showed a similar Km for Phe and pH optimum to the free enzyme. It was resistant against chymotrypsin and trypsin in vitro. To assess the activity in vivo, the free or entrapped enzymes and then Phe were injected into rat duodenum, and cinnamate, a product, in plasma was determined as the most direct evidence of the enzyme activity. The entrapped enzyme but not the free form caused a marked raise of plasma cinnamate. It declined with a half life of about 45 min, which was significantly longer than that (10-15 min) observed upon i.v. administration of cinnamate. These results indicated that the entrapped enzyme was actively degrading Phe in the intestinal tract. Entrapment of phenylalanine ammonia-lyase in fibroin thus provides a new prospect for oral enzyme therapy of phenylketonuria.

Exercise parameters for the prediction of post-training increase in exercise tolerance in patient with stable angina pectoris.

Twenty cases with effort angina underwent exercise training for a mean follow-up period of 38 weeks. Various parameters were investigated to clarify whether or not such parameters can be used to predict an increase in exercise tolerance of patients with effort angina. The increase of exercise tolerance after training was found to be related to a reduction of the myocardial oxygen demand at a given external work load. The maximal heart rate (max HR) the maximal systolic blood pressure (max SBP) and the maximal rate-pressure product (max RPP) could not predict the post-training increase in exercise tolerance. Before training, the maximal oxygen intake (VO2max) was found to be lower, and the HR/VO2max and the SBP/VO2max were higher in the group (11 patients) which showed a good response to the exercise program (effective group) than those in the group (9 patients) which did not (unchanged group). Before training, the HR/VO2max and the SBP/VO2max in the effective group were also higher than those of 96 healthy adults. On the other hand, the HR/VO2max and the SBP/VO2max in the unchanged group were not different from those of the healthy adults throughout the training. It is useful to compare the values of the HR/VO2max and the SBP/VO2max of patients with effort angina to those of healthy adults for the prediction of post-training increase in exercise tolerance.

Experimental study on enzyme distribution and its relation to myocardial ischemic changes following coronary circulatory disturbances.

Coronary artery ligation of canine heart was performed to investigate the relationship between the lactate dehydrogenase (LDH) pattern in myocardium and the distribution of coronary flow, especially in the early stage of ligation and after reperfusion. In the myocardium of normal dogs, the LDH pattern was similar in the left ventricle, the interventricular septum, and the right ventricle; the average LD5:LD4 ratio was 1.1, 1.2, and 1.2, respectively, and consisted mainly of heart type. In the left and right auricles, however, the ratios were 0.3 and 0.2, respectively, lacking heart type. In the left ventricle, LD5:LD4 ratio in the subendocardium was different from that in the subepicardial layer. Blood flow distribution in canine myocardium was investigated by the fluorescent pattern on the cut surface of heart, in which 10% fluorescein sodium was injected into the cavity. By this method the evolution of the ischemic area from the endocardial layer to the epicardial side following coronary artery ligation and the effect of reperfusion on the ischemic area were clarified. Electron microscopic studies indicated that loss of mitochondrial function may account for the irreversibility of myocardial cell alteration. A new method for studying enzyme localization in tissues was introduced for studying LDH isoenzyme distribution in normal and injured myocardium.