巻号一覧
35 巻, 4 号
選択された号の論文の14件中1～14を表示しています
- |<
- <
- 1
- >
- >|
-
Yoshiyuki HONDA1985 年 35 巻 4 号 p. 535-544
発行日: 1985年
公開日: 2006/07/28
ジャーナル フリーControl of ventilation at rest and in exercise was studied in subjects whose carotid bodies were bilaterally resected (BR) for the treatment of bronchial asthma some 30 years ago. Ventilatory activities of the carotid body were estimated to be responsible for about 90% and about 30% of the hypoxic and hypercapnic responses, respectively. The BR subjects still revealed a weak hypoxic chemosensitivity, called residual hypoxic response (RHR). The nature of RHR was discussed in detail.
Exercise hyperpnea was found to be depressed in the BR subjects when compared with the subjects with similarly impared pulmonary function. This result appears to support the oscillation hypothesis in explaining exercise hyperpnea.抄録全体を表示PDF形式でダウンロード (832K) -
Hidenori MASUYAMA, Setsuko AKIYAMA, Yoshiyuki HONDA1985 年 35 巻 4 号 p. 545-552
発行日: 1985年
公開日: 2006/07/28
ジャーナル フリーOverall open-loop gain of the CO2-ventilation feedback control system in hypoxia (GHCO2) was determined on 8 male and one female healthy subjects. They breathed in a closed circuit, and were subjected to the progressive hypoxia test. This procedure was first conducted without dead space (DS), then with 250, 500, and finally 750ml DS, consecutively. GHCO2 was calculated by dividing the slope of the CO2 response curve (S) by that of the metabolic hyperbola (SL). GHCO2 was considerably larger than the overall open-loop gain of the O2-ventilation feedback control system (GO2) previously obtained. This was ascribed to the facts that S was larger than the slope of the hypoxia response curve, and that the absolute value of SL in GHCO2 was smaller than that in GO2.抄録全体を表示PDF形式でダウンロード (615K) -
Toshiyuki ITOH, Kenju MIKI, Taketoshi MORIMOTO1985 年 35 巻 4 号 p. 553-566
発行日: 1985年
公開日: 2006/07/28
ジャーナル フリーThe changes of the distribution of body fluid following acute isotonic dialyzation were studied from the results of continuous monitoring of extracellular fluid volume and physiological parameters. An indicator of extracellular space, 51Cr-EDTA, was injected into spleno-nephrectomized dogs. After the equilibrium of tracer dilution was attained, 10ml/kg of plasma water was isotonically withdrawn by means of a dialyzer of hollow fiber type. The volumes of extracellular fluid (ECF) and plasma (PV) were continuously monitored for 80min and plasma osmolality was measured at 10min intervals. At the 50-60th min after the fluid modification, the reduction of PV was only 3.8ml/kg and that of ECF was 4.2ml/kg. The continuous profile of ECF change showed a significant mobilization of water from intracellular fluid (ICF) soon after the dialyzation. It is concluded that, in the state of hypovolemia, plasma fluid is replenished with the transvascular fluid absorption from interstitial space and that, concomitantly, the reduction of ISF is restituted with the fluid mobilization from ICF into extracellular space within the early stage of 1hr. Good linear correlation was found between the amount of mobilized water from ICF and the increment of plasma osmolality. An increase in osmotic force was considered the mechanism which caused the fluid shift. These findings suggest that the change in plasma osmolality is a good predictor of mobilized volume from ICF in hypovolemia. The effects of inverse fluid modification, i.e., isotonic infusion, were also compared.抄録全体を表示PDF形式でダウンロード (1060K) -
Changes in Action Potential and β-Adrenergic Effects of the Circular Muscle of Postpartum Rat UterusKeiji MARUTA, Yumiko MIZOGUCHI, Takuro OSA1985 年 35 巻 4 号 p. 567-579
発行日: 1985年
公開日: 2006/07/28
ジャーナル フリーSpike potential dominated in the circular muscle of postpartum rat uterus during the period between 0 and 15hr after the delivery of the first newborn. During the postpartum period ranging between 20 and 48hr, the plateau potential was dominant. Application of 10-9M isoprenaline strongly depressed the contraction during early postpartum period (0-15hr), and the depressant effect was much smaller thereafter. In vivo treatment of postparturient rats with estradiol-17β (50μg) or progesterone (50μg) for 2 days did not alter the postpartum change in action potential or the effect of isoprenaline. The postpartum changes in muscle properties mentioned above were prevented in the distended portion of uterus, when several fetuses and placentas were artificially kept inside the uterus for 2 days, while other fetuses were delivered out. The hormonal influences on the circular muscle of postpartum rat uterus were discussed in view of the above experimental findings.抄録全体を表示PDF形式でダウンロード (1045K) -
Biswanath KOLEY, Pratima PAL, Juthika KOLEY1985 年 35 巻 4 号 p. 581-590
発行日: 1985年
公開日: 2006/07/28
ジャーナル フリーIn anaesthetized cats, 40 sympathetic sensory units in the bracheocephalic artery (30units) and the descending aorta (10units) were recorded by means of single-unit preparation. Direct evidence is available for the mechanosensitive nature of the receptors in the sympathetic afferents at the level of T3 and T4. Two distinct types of receptors were found (Type I and Type II). Type I receptors, which were fast adapting, gave a spike discharge at each systolic height of pressure (70-110mmHg). However, they sometimes failed to appear even at such systolic pressure. When the systemic pressure was increased by occluding the descending aorta or by infusing adrenaline solution intravenously, the frequency of discharge of Type I receptors increased and they behaved much the same as the typical sinoaortic baroreceptors. Type II receptors were activated by mechanical probing and at high systemic pressure, though they did not fire always synchronously with heart beat. On the basis of the study it may be suggested that Type I receptors are high threshold baroreceptors and like other systemic baroreceptors, play a role in homeostatic control presumably in a state of high blood pressure, but on the other hand Type II receptors do not play such a role.抄録全体を表示PDF形式でダウンロード (705K) -
Akihiro KUROSHIMA, Takehiro YAHATA1985 年 35 巻 4 号 p. 591-597
発行日: 1985年
公開日: 2006/07/28
ジャーナル フリーEffect of immobilization stress on the rat colonic temperature and metabolism was studied in a warm environment of 25°C. Immobilization for 3hr caused hyperthermia accompanied by increased oxygen consumption (VO2) in the warm controls. The hyperthermic effect of immobilization was accelerated after 1week repetition of daily immobilization and it was lessened after 2 to 4week repetition of daily immobilization. The magnitude of VO2 increase was the same throughout the experimental period of 4weeks during the immobilization. Hypothermia was never observed during immobilization. Immobilization-induced hyperthermia was significantly potentiated in the cold-acclimated rats, while VO2, increase did not differ between cold-acclimated rats and warm controls. These results suggest that immobilization stress causes the changes in body temperature through thermogenic and heat-loss mechanisms.抄録全体を表示PDF形式でダウンロード (460K) -
Kanji MATSUKAWA, Ishio NINOMIYA1985 年 35 巻 4 号 p. 599-611
発行日: 1985年
公開日: 2006/07/28
ジャーナル フリーTime courses of heart rate (HR), arterial pressure (AP), and head movement at the beginning of eating were analyzed in conscious cats. The cats were trained to eat when movements of their body trunks were restrained. Food was presented for 10sec at intervals of 100sec. With the abrupt presentation of food, a head-down movement occurred immediately and thereafter eating started with a mean latency of 1.6sec. During eating HR increased by 22% from the preeating value and AP was elevated by 11%. To determine the time relation between the onset of eating and the change in each variable in response to eating, mean time courses of HR, AP, and head movement were obtained from 7-40 trials in each cat. The head-down movement preceded the onset of eating by 1.3sec. The increase in HR preceded the onset of eating by 0.2sec; the change in AP followed it by 3-4sec. This indicated that the increase in HR was not induced reflexly either by food intake or by the change in AP. After administration of hexamethonium, the changes in HR and AP in response to eating were abolished, although eating was evoked by the food presentation. Additionally, the increase in HR was also reduced by propranolol and atropine. Thus, the acceleration of HR at the beginning of eating may be induced by central activation of the autonomic nervous system.抄録全体を表示PDF形式でダウンロード (976K) -
Masa TAKAUJI, Masaaki TSUTSU-URA, Hideaki KANAYA, Torao NAGAI1985 年 35 巻 4 号 p. 613-627
発行日: 1985年
公開日: 2006/07/28
ジャーナル フリーThe inactivation of potassium (K) contractures induced by prolonged conditioning depolarization and repriming after 190mM K+ contractures were studied at both room and low temperatures using frog single twitch muscle fibers. Effects of conditioning K+ depolarization and external Ca2+ reduction on the biphasic K contractures were also studied. When the conditioning depolarization with 15-30mM K+ was prolonged, the peak tension of test 190mM K+ contractures was inhibited in parallel with the shortening of plateau duration at both room and low temperatures. Such parallel changes were also observed during the early stage of repriming after 190mM K+ contracture at both temperatures. On the other hand, the peak tension of the secondary component of the test 80mM K+ Contractures was rather potentiated by the conditioning depolarization, even though the time course of the component was markedly shortened. The foregoing changes were also illustrated in a diagramatic way. These results suggested that the peak tension and the time course of the test K contractures after conditioning depolarization and during repriming may be determined by a balance between the activation and the inactivation processes of the contractures. This view is supported by the results obtained under conditions in which the concentration of external Ca2+ was reduced. Furthermore, based on additional experimental results, it was suggested that the initial component is not accompanied by an inactivation process and that Ca uptake by sarcoplasmic reticulum may partially contribute to determining the spontaneous relaxation phase of the secondary component, at least at room temperature.抄録全体を表示PDF形式でダウンロード (1020K) -
Noriko TAKUWA, Tadahito SHIMADA, Hisashi MATSUMOTO, Masayoshi HIMUKAI, ...1985 年 35 巻 4 号 p. 629-642
発行日: 1985年
公開日: 2006/07/28
ジャーナル フリーGlycylglycine (Gly-Gly) transport across rabbit small intestinal brush border membrane vesicles was studied in the presence and absence of a Na+ gradient or a pH gradient. The transport was found to be entirely independent of Na+ but significantly stimulated by lowering extravesicular pH (pHo). The maximum stimulation was seen at pHo 5.5, where the uptake rate was about 2-times higher than the control value. FCCP, a protonophore, abolished the stimulating effect of low pHo, and low pHo conditions without a pH gradient did not stimulate the uptake rate. Overshoot uptake of Gly-Gly was observed when a pH gradient of 2 pH units was imposed across the vesicular membrane. Valinomycin-induced inside-negative K+ diffusion potential also had a stimulating effect on the uptake, and fluorescence measurements of vesicular suspensions containing diS-C3-(5) revealed the occurrence of depolarization of the vesicular membranes when Gly-Gly was added to the suspensions. Kinetic study showed that a pH gradient caused a decrease of Kt for Gly-Gly without affecting Vmax. All the data obtained indicate that Gly-Gly transport is independent of Na+, dependent on a H+ gradient, and electrogenic, suggesting the mechanism of cotransport with H+.抄録全体を表示PDF形式でダウンロード (1086K) -
Ken-ichi HONMA, Sato HONMA, Tsutomu HIROSHIGE1985 年 35 巻 4 号 p. 643-658
発行日: 1985年
公開日: 2006/07/28
ジャーナル フリーPhase response curves (PRC) for the spontaneous locomotor rhythm were constructed by applying short light pulses to rats in constant darkness (DD). The offset of locomotor activity as well as the onset was taken as a phase reference (offset PRC vs. onset PRC). The amount of phase shift yielded by light pulses was evaluated on the next day of pulse treatment (immediate PRC) and also after completion of a new steady state (steady state PRC). Significant differences in shape were observed between the onset and offset PRCs as well as between the immediate and steady state PRCs. In the immediate onset PRC, an area under the phase advance part (A) was absent, while it was present in the immediate offset PRC. In contrast, the steady state PRCs for activity onset and offset were essentially the same. The shape of steady state PRC depended on the free-running period in DD (τ). In the PRCs of long τ rhythms, the range covered by the phase delay area (D) was lengthened without changing its amplitude, resulting in a larger D/A ratio. A strong positive correlation was detected between τ and activity time (α). The steady state PRC shapes also depended on α; the D/A ratio was larger in a long α rhythm than in a short α. These results are in good agreement with the hypothesis that the circadian locomotor rhythm of nocturnal rodents is regulated by two coupled oscillators.抄録全体を表示PDF形式でダウンロード (1050K) -
Keiko MASHIMO1985 年 35 巻 4 号 p. 659-671
発行日: 1985年
公開日: 2006/07/28
ジャーナル フリーSome single myocardial cells cultured from the neonatal mouse atrium and ventricle, which beated spontaneously, stopped contracting dose-dependently with the addition of ethanol to the culture medium. The cells of the atrium were arrested more easily than those of the ventricle. The myocardial cells which continued beating in the ethanol medium showed chronotropic responses in a dose-dependent manner. The beat rate of both atrial and ventricular cells changed very little on the addition of a low concentration of ethanol (12.5mM). Atrial cells showed negative chronotropic responses to high concentrations of ethanol (50 and 200mM), while ventricular cells showed transient positive responses. Addition of acetaldehyde (100μM) slowed the beating of atrial cells severely and that of ventricular cells moderately, but failed to arrest either type of cell. The addition of hyperosmolar medium containing 200mM sucrose caused almost no chronotropic effect on atrial cells but a strong negative one on ventricular cells, and arrested very few of either type of cell. The transient positive chronotropic responses of ventricular cells to ethanol seemed unrelated to either acetaldehyde contained in the ethanol medium or the hyperosmolarity of the ethanol medium.抄録全体を表示PDF形式でダウンロード (1046K) -
Pipat CHERDRUNGSI1985 年 35 巻 4 号 p. 673-682
発行日: 1985年
公開日: 2006/07/28
ジャーナル フリーAcute exposure to high altitude for 1 day in rats caused an increase in hematocrit (Hct) with no change in mean arterial blood pressure (mABP) from the non-altitude control, whereas after prolonged exposure to altitude (5-6weeks) there were increases in both Hct and mABP. No changes in total plasma protein (TPP) and plasma osmolality (POsm) from control rats were observed in all altitude-exposed animals. The ability of the acutely and chronically altitude and non-altitude exposed rats to resist hemorrhage was studied. Hemorrhage was standardized at mABP in the range of 30-35mmHg. Chronic exposure to altitude increased the initial and maximum volume of blood withdrawn as well as the oligemic and survival times, whereas acute altitude exposure did not. The higher ability to resist standardized hemorrhagic shock of the chronically altitude exposed rats seemed to result, in part, from their greater hemodilution and better arterial blood pressure regulation. No difference in the rate of hemodilution as well as hemorrhagic tolerance was observed between the 1-day altitude and control rats. The difference in rate of hemodilution between the chronic altitude and control animals could not be due to arterial hyperosmolality since the magnitude of change in POsm during blood loss was the same for all animal groups.抄録全体を表示PDF形式でダウンロード (808K) -
Yuji KIKUCHI, George M. HUGHES, Tomiyasu KOYAMA, Yoshihiro KAKIUCHI, T ...1985 年 35 巻 4 号 p. 683-688
発行日: 1985年
公開日: 2006/07/28
ジャーナル フリーBlood of Pacific salmon was studied with particular interest in red blood cell (RBC) deformability in relation to migration. Blood samples were taken via cardiac puncture or chronic cannula placed in the dorsal aorta and heparinized. As an index of RBC deformability the mean passage time of single RBCs through micropores of 8μm in diameter and 10μm in length was determined under a pressure difference of 10cmH2O. Despite about 100mOsmol/l difference in plasma osmolality, there was no marked difference in RBC passage time between fish in seawater and those well acclimatized to freshwater. However, it seemed probable that a transient decrease in RBC passage time, i.e., an increase in RBC deformability, occurred immediately following transfer from seawater to freshwater. Plasma osmolality decreased to about 300mOsmol/l within 1hr after the transfer and showed no fluctuations thereafter. The temperature dependence of RBC deformability was much smaller in comparison with those previously observed in yellowtail and carp; salmon RBCs were still highly deformable even at 5°C, a possible temperature of cold river water.抄録全体を表示PDF形式でダウンロード (485K) -
Takakazu KOBAYASHI, Chiyoko ICHIKAWA, Haruo SUGI1985 年 35 巻 4 号 p. 689-692
発行日: 1985年
公開日: 2006/07/28
ジャーナル フリーSinusoidal vibrations (10-100Hz, 0.5-2.5%) reduced catch tension in the anterior byssal retractor muscle of Mytilus edulis, while the stiffness measured as the tension increment in response to the stretch phase of vibration did not change appreciably, indicating that the vibration-induced reduction of catch tension may not be simply explained as being due to the detachment of cross-links between actin and myosin.抄録全体を表示PDF形式でダウンロード (269K)
- |<
- <
- 1
- >
- >|