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Volume 26, Issue 3
Displaying 1-6 of 6 articles from this issue
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Osamu KASHIMURA, Gou UEDA1989 Volume 26 Issue 3 Pages 125-133
Published: November 01, 1989
Released on J-STAGE: December 10, 2010
JOURNAL FREE ACCESSThe effect of physical exercise training on thermogenesis to acute cold exposure was investigated in male rats. Rats were subjected to physical exercise programs for 9 weeks. The non-exercise control, cold-acclimated and exercise-trained groups were exposed to -5°C for 2 or 3 hours.
Exercise training caused a significant hypertrophy of the heart. At the end of 2-hr cold exposure, there was a significant fall in the colonic temperature of the non-exercise control group, but no fall in the exercise and cold-acclimated groups. There was less thermal response to norepinephrine in the trained group than in the cold-acclimated group. Greater fall in colonic temperature was caused by hexamethonium injection 30 min after cold exposure in the cold-acclimated rats than in the control and the trained rats. After the administration of 2-deoxyglucose, an inhibitor of glucose utilization, the cold-acclimated rats maintained higher colonic temperature during cold exposure than the trained and control rats. The extent of decrease of plasma glucose concentration due to cold exposure was less in the trained and the cold-acclimated groups than in the control group. The plasma free-fatty acids concentration increased in the control and the trained groups in the cold, but the extent did not differ between both groups. The degrees of increases of plasma norepinephrine, urinary norepinephrine and epinephrine excretion due to cold exposure were less in the cold-acclimated and the exercise-trained rats than in the control rats.
These results suggest that the physical exercise-training causes an improved cold tolerance in rats. It is inferred that an improved capacity of cold-induced thermogenesis is due to an improved norepinephrine-independent thermogenesis possibly being attributable to preferential utilization of carbohydrate. Key words: Acute cold exposure, Nonshivering thermogenesis, Catecholamines, 2-DeoxyglucoseView full abstractDownload PDF (1052K) -
Kiyoshi MORIYA1989 Volume 26 Issue 3 Pages 135-142
Published: November 01, 1989
Released on J-STAGE: October 13, 2010
JOURNAL FREE ACCESSUsing a cycle ergometer, male students of 19-22 yrs of age, who had been undergoing physical training over three years, were made to exercise for 30 min at a submaximal level estimated at 64 to 93% (mean 74%) of the maximal level. After 30 min of the loads, the maximal increase in rectal temperature was observed. It was + 1.0±0.2 (mean ±SE) °C. Skin temperature of the anterior thigh lowered temporari-ly just after the onset of the exercise load then increased in all subjects. On the other hand, skin temperatures of the chest and the lateral upper arm decreased temporarily in some of the subjects at the onset of the load and then increased. The mean skin temperature calculated by a three point method increased markedly. The maximal increase of +2.8 ±0.4°C was observed at 30 min after the start of the load. Hematocrit value increased significantly at 3 min after the start of the exercise load and this higher level was maintained throughout the load, suggesting a movement of water probably induced by nonthermal stimulus from plasma to extracellular space. The changes in the concentration of plasma lactic acid, glucose and free fatty acids suggest that both aerobic and anaerobic metabolism were activated under the exercise of the submaximal level used in this experiment. The concentration of blood glucagon increased under the exercise load and the level of plasma insulin did not change during the loadView full abstractDownload PDF (984K) -
Yasuko MARUYAMA, Teruko TAMURA1989 Volume 26 Issue 3 Pages 143-154
Published: November 01, 1989
Released on J-STAGE: December 10, 2010
JOURNAL FREE ACCESSCombinations of clothing provide different thermal stimuli on the various parts of the human body. The effects of local cooling of the human body on the skin temperature, the thermal sensation and comfort were examined by using the coverall type clothing. The experimental clothing was made to be devided into 14 parts, each of which could be removed separately. The subjects were 3 young healthy female students aged from 20 to 24 years old. They were exposed to thermal environment (20°C, 50%RH) with the coverall type clothig for 30min and then exposed to local cooling by removing each part of the clothing for 40 min. The results were as follows;
1) Local cool stimulation of the trunk affected more on the skin temperature, general and local thermal sensation than that of the extremities.
2) The general thermal sensation was affected the most by the local skin temperature and the local thermal sensation of the back and the upperarm.
3) The correlation coefficient between general thermal sensation and mean skin temperature was 0.60, which was lower than the result obtained by Vokac et al.View full abstractDownload PDF (1240K) -
Kunihiko HIRASAWA, Akio KOYAMA, Kohtaroh YAMAMURA1989 Volume 26 Issue 3 Pages 155-160
Published: November 01, 1989
Released on J-STAGE: October 13, 2010
JOURNAL FREE ACCESSWe made a clinical and statistical evaluation on the occurrence of acute myocardial infarction regarding the relation between the occurrence and meteorology in the cold inland area of Japan (Asahikawa District) for the past 10 years (1976-1985) .
Monthly fluctuation of occurrence was not found to be statistically significant in the total of 581 cases. The maximum and the minimum meteorological temperatures of the investigated 10 years were graded in every 5°C, and the expected frequency of the occurrence was calculated in proportion to the percentage of each graded temperature. The expected frequency was compared with the real frequency of the occurrence by means of chi square test, and there was no significant difference of these two frequencies.
A cold period in Asahikawa District was defined in this study as the term while ordinary mean atmospheric temperatures were below 0°C (from 7 Nov. to 16 Apr.) . In the 10-years' cold periods, there happened 269 cases of acute myocardial infarction, and 245 days were proved to be the days with occurrences. According to the data by the Meteorological Observatory, 10 meteorological items were selected.
Canonical discriminant analysis was applied to the 10 meteorological items between the 245 days with occurrences and control 245 days without occurrences in the cold periods of the investigated 10 years, and between the 37 days with outdoor occurrences and control 37 days without occurrences. The F values of 0.0003 and 0.0155 in the above canonical discriminant analysis were respectively small (<< F19 (0.25) =1.51) . Therefore, the 10 meteorological items could not discriminate the probabilities between the days with occurrences and the days without occurrences of myocardial infarction in the cold periods in Asahikawa District.View full abstractDownload PDF (737K) -
Tokuo OGAWA, Yuka YAMASHITA, Junichi SUGENOYA, Norikazu OHNISHI, Keiko ...1989 Volume 26 Issue 3 Pages 161-167
Published: November 01, 1989
Released on J-STAGE: October 13, 2010
JOURNAL FREE ACCESSValidity of tympanic temperature (Tty) as an indicator of brain temperature in man was evaluated by examining the occurrence of bilateral differences in Tty and its effect on regional sweating. First, in a warm environment, a unilateral Tty was successfully lowered in most cases by blowing on one side of the head with cool air, and by ventilating a circumscribed area of the lateral neck. Tty on the contralateral side was slightly lowered in some cases with the hemi-face blowing, whereas it was even elevated slightly in some cases with the neck ventilation. A small difference in sweat rates on the bilateral forearms was observed in many cases, concomitantly with the bilateral difference in Tty, being lower on the cooled side. On the other hand, cooling of a unilateral upper or lower extremity by cool water immersion failed to produce bilateral difference in Tty or in sweat rate. Secondly, unilateral stellate ganglion blocking by local anesthesia in a warm environment caused a slight but consistent lowering of Tty on the ipsilateral side. It is suggested that the ganglion blocking causes an increase in blood flow of the ipsilateral brain, thereby facilitating the ipsilateral cooling. While inhibition of sweating on the ipsilateral upper limb was inconsistent after the ganglion blocking, sweating on the ipsilateral lower limb declined as well in a few cases. The latter effect may have been secondarily brought about by the lowering in the ipsilateral brain temperature.
The present results strongly suggest that the asymmetry in brain temperature can cause a slight bilateral difference in thermoregulatory responses, such as sweating and less clearly in cutaneous circulation, and that changes in brain temperature is reflected well on Tty.View full abstractDownload PDF (876K) -
Akie HONMURA, Reiko UHARA, Eiichi HARUKI, Sabro YAGISHITA, Fukuko KIMU ...1989 Volume 26 Issue 3 Pages 169-172
Published: November 01, 1989
Released on J-STAGE: October 13, 2010
JOURNAL FREE ACCESSNeonatal male Wistar rats were separated into two groups at 5 days of age, and were subjected to daily, 3-h exposure to oxygen (O2 group) or air (control group), respectively. The exposures were conducted in a translucent chamber using 100% O2 or room air. In this exposure system, PaO2 measured at 1-h exposure showed about 3-fold increase, whereas PaCO2 and pH were not changed. Blood pressure measurement with tail-cuff method, which was conducted following 7-or 9-week exposure, revealed a significant increase in blood pressure in the O2 group compared to that in the control group. SOD activity and lipid peroxide in blood, as measured after 9-week exposure, were tended to be higher in the O2 group than in the control group, but the difference was not significant. The kidney weight was significantly smaller in the O2 group than in the control group, but light microscopic study showed no significant changes in both groups. The results suggest that repeated exposures to oxygen in the immature stage cause long-term changes in cardiovascular functions.View full abstractDownload PDF (434K)
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