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Volume 31 (1981)
- Issue 6 Pages 809-
- Issue 5 Pages 613-
- Issue 4 Pages 445-
- Issue 3 Pages 285-
- Issue 2 Pages 131-
- Issue 1 Pages 1-
Volume 31, Issue 4
Displaying 1-15 of 15 articles from this issue
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Satoru SUNANO, Eisaku MIYAZAKI1981 Volume 31 Issue 4 Pages 445-456
Published: 1981
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSThe effects of temperature and metabolic inhibitors on short tetanus contraction of was deferens were studied. The contraction height increased by lowering temperature from 35°C, and decreased with a decrease in temperature below 25°C. The maximum speed of contraction and relaxation decreased by lowering the temperature, showing a transition of Q10values at 25°C. The Q10 value for the maximum speed of contraction was 1.7 between 35 to 25 °C, and 5.3 between 25 to 10 °C. The Q10 value for the maximum speed of relaxation was 1.9 between 35 and 25 °C, and 13.0 between 25 and 15 °C. The time to peak tension and to half relaxation increased by lowering temperature. The Q10 values also showed a transition at 25 °C. The Q10 value for the time to peak tension was -2.5 between 35 and 25°C, and -5.0 between 25 to 5 °C. The Q10, value for the time to half maximum relaxation was -3.1 between 35 and 25 °C, and -5.7 between 25 and 5°C. NaN3 and KCN and DNP inhibited the contraction. However, time to peak tension and half maximum relaxation time were not altered. Although the maximum speed of contraction and relaxation decreased, this was caused only by the reduction in peak tension. O2-free or glucose-free treatment caused only a slight decrease in peak tension. Neither time to peak tension nor half maximum relaxation time was altered. The differences between the effects of temperature and metabolic inhibition are discussed.View full abstractDownload PDF (1214K) -
Tadaomi AIKAWA, Taeko HIROSE, Itsuro MATSUMOTO, Tatuzi SUZUKI1981 Volume 31 Issue 4 Pages 457-463
Published: 1981
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSThe left adrenal gland of the hypophysectomized-nephrectomized dog was perfused in situ with the blood from the femoral artery of the hypophysectomized-nephrectomized donor dog. After infusion of histamine (0.1 mg/min for 5 min) into the arterial inflow circuit, the rates of secretion of aldosterone, corticosterone and cortisol (ng/100 mg adrenal wt. each min) increased from the basal level of 0.66±0.21 (mean±S.E.M.) to 2.24±0.45 at 10 min, from 4±1 to 20±4 at 5 min and from 19±5 to 64± 15 at 5 min, respectively. The maximal increments above the basal value after the infusion of histamine in the secretory rates of aldosterone, corticosterone and cortisol were 51, 16, and 13 % that of the respective steroid after the infusion of ACTH (20 mIU/min for 5 min). The results indicate that histamine has a direct stimulatory effect on the secretion of aldosterone by the adrenal gland as well as on that of corticosterone and cortisol.View full abstractDownload PDF (786K) -
Yasuyuki SUGANO1981 Volume 31 Issue 4 Pages 465-475
Published: 1981
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSHeat production (M), dry heat loss (R+C), evaporative heat loss (E) and rectal temperature (Tre) were measured in a direct calorimeter in female mongrel dogs acclimatized to outdoor climate at Kanazawa (latitude ; 36°35'' N), Japan. M and total dry and evaporative heat losses (HL) were minimum at calorimeter wall temperatures (TW) of 26-29°C in summer and 22-26°C in winter (thermoneutral temperature; TNT). The seasonal shift of the lower critical temperature was confirmed. At TW, below TNT, the values of M and HL were significantly higher in summer. At TW above TNT, these values increased. At TNT and above, M and HL, were significantly higher in winter.(R+C) decreased linearly with increasing. 7; in both seasons. At T. below 26°C, (R+ C) were significantly higher in summer. At TW, above 26°C, E increased greatly. The values of E were significantly higher in winter at TTW, 29- 32°C. Tre remained nearly constant at TNT and below, and increased at TW above TNT in both seasons. Mean body surface temperature (Tsf) decreased with decreasing TW. Body thermal conductance (K) was minimum at TW below 26°C in summer and at TW below 22°C in winter. At TW above these temperatures, K increased significantly. Whole body insulation (I) was significantly higher in winter, particularly atTW18°C. These results suggest that the dogs reared outdoors in winter acclimatized to cold in two ways ; by increasing the insulating effect of the fur coat and by elevating resting heat production.View full abstractDownload PDF (1067K) -
Toshihiko UEMATSU, Yoshiyuki BAN, Naohisa ISHIKAWA, Hiromichi TSURU, T ...1981 Volume 31 Issue 4 Pages 477-489
Published: 1981
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSAn intravascular cuff was devised with a short plastic cylinder and a latex membrane wrapping it, in order to examine the responsiveness of the canine inferior vena cava in vivo. The cuff was inflated by injecting saline through a catheter to make the membrane contact the vascular wall closely, and the change in the cuff pressure was recorded. An in vitro experiment with an isolated segment of the vein proved that the cuff detected quantitatively the active response of the vascular smooth muscle to norepinephrine (NE). The sensitivity to NE under this experimental condition was equal to that obtained previously with the isolated strip preparation. In the in vivo experiments, the cuff inserted into the segment between the liver and the renal veins of the inferior vena cava exhibited spontaneous rhythmic changes in pressure. In response to NE injected intravenously, dose-dependent increases in cuff pressure were observed. The responses recorded with the intravascular cuff were considered to be predominantly the active tension of the vascular smooth muscle, since influences of intestinal motion and changes in venous pressure on the cuff pressure were ruled out. The cuff picked up the response of the supradiaphragmatic segment of the inferior vena cava as well. The method seems to be useful for measuring the tone of larger veins.View full abstractDownload PDF (1327K) -
Akinori NOMA, Hiroshi KOTAKE, Shinichiro KOKUBUN, Hiroshi IRISAWA1981 Volume 31 Issue 4 Pages 491-500
Published: 1981
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSThe slow inward current (is) in the rabbit sinoatrial node cell was studied by the conventional two-microelectrode voltage clamp technique. When is was measured as the difference between two records obtained before and after blocking is with D 600, the fully activated current (is)-voltage relation was non-linear; the conductance decreased in the negative potential range resulting in an almost constant amplitude of is negative to -10 mV. The degree of steady-state activation was about 1 at -5 mV and 0 at -65 mV. The recovery time course of is during repolarization was measured by varying the interval between two sequential depolarizing pulses with various holding potentials. The time constant of the exponential recovery time course was about 120 msec at - 40 mV and decreased to about 40 msec at -70 mV. The steadystate conductance of is, calculated from the activation and inactivation curves, produced a large hump in the steady-state current voltage relation between -60 and -20 mV, which was not observed in the experiment. When the above kinetics were incorporated, the S-A node model failed to discharge the spontaneous activity. The activation and inactivation curves which can simulate the experimental I-V curve and the action potential were proposed.View full abstractDownload PDF (1013K) -
Masayosi GOTO, Mami URATA, Atsuko YATANI, Takao FUJINO1981 Volume 31 Issue 4 Pages 501-513
Published: 1981
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSAs adenosine has a potent stabilizing action on catechol-amine stimulation in the myocardium, the mode of interaction of adeno-sine and acetylcholine (ACh) was studied with regard to the membrane potential, current and tension components of the bullfrog atrium, using the single or double-sucrose gap method. Adenosine (10-4-3×10-3 M) augmented the twitch contraction in the presence of ACh (10-9-5×10-7m) by lengthening the duration of the action potential. The dose-tension response curve for ACh was modified by adenosine, producing a rise of the inhibitory threshold of ACh, and the modification showed a non competitive interaction of these compounds. Under the voltage clamp, ACh-induced steady current (IACh) was inhibited by adenosine non-competitively. The known inhibition of slow inward current (Is) by ACh was enhanced by adenosine, while the delayed outward current (Ix) was markedly suppressed. Is-dependent and -independent tension com-ponents were both inhibited by adenosine, thereby suggesting a decrease in intracellular concentrations of calcium. The potent suppression of IACh and Ix induced by adenosine, however, appeared to mitigate the inhibitory action of ACh on the action potential and twitch contraction.View full abstractDownload PDF (5693K) -
Tadao KISHIKAWA1981 Volume 31 Issue 4 Pages 515-536
Published: 1981
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSThe relationships among progesterone and oestradiol contents in the sera, membrane activities, catecholamine actions and contents of cyclic nucleotides were investigated in the rat myometrium during gesta-tion and post partum, and under conditions of hormone treatment. Progesterone contents declined and oestradiol contents increased in the sera on the 21st day of gestation. During the late stage of gestation, oestradiol related to a regularity, and progesterone to an irregularity, in the spike generation of myometrial cells. In the longitudinal muscle, catecholamines dominantly activated the β-adrenoceptors during gesta-tion, but activation of the α-adrenoceptors was seen during and after delivery, while in the circular muscle, α-adrenoceptor dominancy altered to β-adrenoceptor dominancy at the last stage of gestation. In both muscle cells, increases in the cyclic AMP contents and activations of the β-adrenoceptors by application of catecholamines appeared simultane-ously. At the late stage of gestation, oestradiol treatment rather than pro-gesterone increased the cyclic AMP contents, in both muscle layers. In the light of the results, alteration in the myometrial properties during the last stage of gestation and delivery cannot be explained solely by progesterone withdrawal phenomena.View full abstractDownload PDF (2182K) -
Chris ACHENBACH, Otto HAUSWIRTH, Heinz-Dieter WEHNER, Rolf ZISKOVEN1981 Volume 31 Issue 4 Pages 537-545
Published: 1981
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSThe action of β-adrenoceptor antagonist Penbutolol on the current underlying pacemaker activity in cardiac Purkinje fibres was analysed using the voltage clamp technique described by DECK et al.(1964).
After the application of adrenalin, β-blockers are able to counteract the well known shift of the s-kinetics of the pacemaker current. However, without any prior application of adrenalin the β-blocker Penbutolol has no effect on these kinetics except for a small depression of the am-plitude of the pacemaker current tails. The rectifier properties of the pacemaker current and the negative slope of the fully activated current vol-tage relationship of iK2 are unchanged.
Penbutolol is able-even after a longer period of washout (about 60-90 min was necessary)-to protect the β-adrenoceptors from the action of adrenalin (HASHIMOTO et al., 1979). These findings suggest that β-blockers are competitive inhibitors of β-stimulators and further support the notion that the pacemaker current in cardiac Purkinje fibres is controlled by β-adrenoceptors.View full abstractDownload PDF (857K) -
Junichi TANIGUCHI, Shinichiro KOKUBUN, Akinori NOMA, Hiroshi IRISAWA1981 Volume 31 Issue 4 Pages 547-558
Published: 1981
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSSingle cells or cell clusters composed of 3-10 cells were isolated from the S-A and A-V nodes of the rabbit heart by coronary perfusion of collagenase dissolved in Ca-free Tyrode solution (0.04 %, for 1 hr). For comparison, atrial and ventricular cells were also isolated from the same heart. Shapes of the isolated nodal cell were either rod or round and nodal cells were slightly smaller than ventricular cells. Spon-taneous activity was observed in both rod and round nodal cells. The action potentials had the configurations similar to those recorded from larger conventional preparations. The membrane current recorded from the small nodal cell clusters (5-10 cells) by the two-microelectrode voltage clamp technique showed a time course similar to that of previous recordings from conventional preparations, but the amplitude of the currents was 5-10 times smaller. The isolated cells showed normal sensitivities to both acetylcholine and epinephrine. Findings given in this study indicate that the isolated cells maintain the typical membrane characteristics of the nodal cells and that they are suitable for electro-physiological studies of the cardiac pacemaker cell.View full abstractDownload PDF (4672K) -
Yuzo NINOMIYA, Masaya FUNAKOSHI1981 Volume 31 Issue 4 Pages 559-570
Published: 1981
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSResponses of rat chorda tympani fibers to stimulations of the tongue with linearly rising anodal currents of varying rise rates and intensities, cathodal currents and chemical solutions representing the four basic taste qualities were obtained. Single fibers were classified into four types according to their response patterns to anodal and cathodal current stimulations of the tongue. Type Al fibers responded only to an anodal current with both transient and steady, response phases. Type A2 fibers responded only to an anodal current with only a steady response phase. Type B fibers responded to both anodal and cathodal currents. Type C fibers responded only to a cathodal current. Sensitivity to the rate of anodal current rise varied widely among individual chorda tympani fibers. The NaCl-sensitive fibers were most sensitive, the tartaric acid-sensitive fibers next, and the sucrose-sensitive fibers least. Fibers responding to cathodal current were sensitive to quinine hydrochloride. Fibers which showed rhythmic bursts of discharges in response to chemical stimuli also gave a similar discharge pattern in response to electrical stimulation.View full abstractDownload PDF (1233K) -
Ryoji KAWASAKI1981 Volume 31 Issue 4 Pages 571-583
Published: 1981
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESS1. The effect of medullary stimulation on breathing movement was studied in the adult lamprey, Entosphenus japonicus.
2. A single, as well as low frequency (less than 5 Hz) pulses applied extracellularly to the medial part of the medulla (as shown in Fig. 1) produced one-to-one movement (contraction followed by relaxation) of branchial baskets, which are similar in shape, as well as in bilateral synchronization, to spontaneously occurring movement.
3. Medullary stimulation never produced active immediate relaxation of branchial baskets. Intravenous application of d-tubocurarine resulted in sustained relaxation of branchial baskets. EMG recorded from branchial muscles always correlated with the phase of contraction of branchial baskets.
4. The rhythm of respiratory movement was reset by driving stimuli at low frequencies. Alteration of driving frequency did not markedly affect the duration of branchial movement.
5. With high frequency stimulation (more than 5 Hz), individual responses fused into one continuous contraction (sustained compression) of branchial baskets ; it may be called a systolic arrest or expiratory arrest of breathing movement.
6. After the repetitive stimulation had been turned off, there was a pause in the respiratory movement. This sustained relaxation of branchial baskets may be called a diastolic arrest or inspiratory arrest. During this arrest, applied pulse shocks induced one-to-one movement of branchial baskets.
7. These results were discussed whilst considering an analogy between respiratory rhythmogenesis in the lamprey and cardiac pacemaking in crustacean heart ganglion.View full abstractDownload PDF (1331K) -
Akira NAGATA, Masuo MURO, Toshio MORITANI, Takayoshi YOSHIDA1981 Volume 31 Issue 4 Pages 585-597
Published: 1981
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSThis study examined the potential use of myoelectric signal analysis for determination of anaerobic threshold (AT). Ten college students performed incremental exercise on a bicycle ergometer during which blood samples from either the brachial or radial artery were drawn and corresponding intergrated electromyogram (IEMG) and power spectra also were recorded. Blood AT was determined by observing the changes in arterial blood lactate, PO2 PCO2, HCO3-, and pH. EMG AT was determined by the non-linear increase in IEMG and abrupt increase in frequency band width at 70 % of the peak frequency (FRQ70%) which could represent the most active frequency band. The results indicated that a significant increase in FRQ70% occurred immediately after the occurrence of blood AT (p<0.05). However, no significant increase could be found in peak frequency. Regression analyses revealed that EMG AT VO2 correlated significantly with blood AT V02 (r=0.921, p<0.001) and with gas exchange AT VO2 (r=0.921, p<0.001). It was concluded that analysis of myoelectric signals, which reflect motor unit recruitment and discharge frequency, could provide a non-invasive estimateof AT.View full abstractDownload PDF (1338K) -
Yun-feng CHERN, Mao-tsun LIN1981 Volume 31 Issue 4 Pages 599-603
Published: 1981
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSIntraventricular administration of either norepinephrine, tyramine or angiotensin II produced dose-dependent hypothermia, decreased metabolism and lowered cutaneous temperatures in Taiwan monkeys at ambient temperatures of 4 and 22°C. The hypothermia reflected the heat storage consequent to the net effects of decreased heat production and decreased heat loss. In heat (35°C), these agents produced dose-dependent hyperthermia in monkeys. The hyperthermia was brought about mainly by a decrease in dry heat loss.View full abstractDownload PDF (480K) -
Itsuro MATSUMOTO, Taeko HIROSE, Tadaomi AIKAWA1981 Volume 31 Issue 4 Pages 605-608
Published: 1981
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSIn trypsin-dispersed adrenal cells of the guinea-pig, the production of 11-hydroxycorticosteroids in vitro was found to be significantly stimulated by 10-7-10-4 M histamine and the maximum steroidogenic response (1.7-fold increase in 11-hydroxycorticosteroid production) was observed at 10-6 M. The stimulatory action of histamine on steroidogenesis was blocked by cycloheximide treatment.View full abstractDownload PDF (408K) -
Shunji UEDA, Yasunobu OKADA, Wakoh TSUCHIYA, Toshihiko YADA, Masao UED ...1981 Volume 31 Issue 4 Pages 609-612
Published: 1981
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSThe intracellular Cl- activity (aCli) and the membrane potential (Vm) were simultaneously measured in cultured L-strain fibroblasts, using a Cl--selective liquid ion-exchanger microelectrode and a standard microelectrode. The oscillations of aCli and Vm were found to occur concomitantly. A decrease in the aCli value was associated with the spontaneous hyperpolarization. The depolarization produced by current injection resulted in an increase in aCli. These data suggest that the membrane permeability to Cl- is significantly high during the Vm oscillation in the L cell.View full abstractDownload PDF (380K)
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