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Volume 32 (1982)
- Issue 6 Pages 895-
- Issue 5 Pages 689-
- Issue 4 Pages 493-
- Issue 3 Pages 327-
- Issue 2 Pages 153-
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Volume 32, Issue 2
Displaying 1-16 of 16 articles from this issue
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Isao HASHIMOTO, Mark B. KNUDSON, Earl G. NOBLE, Gary A. KLUG, Philip D ...1982 Volume 32 Issue 2 Pages 153-160
Published: 1982
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSThe role of the adrenergic system in regulating glycogenolysis during exercise was studied in rats. Alterations in the adrenergic system were produced by injections of 6-hydroxydopamine (6-OHD), surgical removal of the adrenal medulla (ADMX), or the combination of ADMX and 6-OHD injection. Exercise was treadmill running at 22 m/min for 60 min. Colonic temperature averaged 2.8°C higher in the exercised than control rats. Exercise reduced the glycogen of the liver and skeletal muscles of all groups. The glycogen concentrations of the soleus and red portion of the gastrocnemius muscles of the ADMX and ADMX-6- OHD groups were about 3.8 and 2.5 times higher after exercise than those of the normal-exercised rats. Glycogen depletion of the white portion of the gastrocnemius muscle was similar for all exercised groups. 6-OHD treatment depleted the catecholamines of the myocardium. These results demonstrate that glycogen depletion during exercise occurs in rats devoid of adrenergic control. However, differences between types of skeletal muscle suggest that factors other than the adrenergic system may be involved in controlling glycogen metabolism during exercise.View full abstractDownload PDF (904K) -
Takashi NAGASAWA1982 Volume 32 Issue 2 Pages 161-170
Published: 1982
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSRed blood cells (RBCs) from phenylhydrazine-injected rats were separated according to their specific densities by centrifugation on a polyvinyl-pyrrolidone-coated colloidal silica matrix (Percoll). The deformability and osmotic fragility of fractionated RBCs were measured by ektacytometer and coil planet centrifuge, respectively. Immature reticulocytes, the least dense RBC subpopulation, were less deformable and osmotically more resistant than normal RBCs. Heinz-body containing RBCs, the most dense subpopulation, showed reduced deformability and increased osmotic fragility. These findings suggest that young reticulocytes have increased membrane stiffness and that Heinz-body containing RBCs have an extremely rigid membrane.View full abstractDownload PDF (5240K) -
Toshifumi MORIMOTO, Hitoshi INOUE, Yojiro KAWAMURA1982 Volume 32 Issue 2 Pages 171-182
Published: 1982
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSThe masseter and the mylohyoid nerves were examined using electron microscopy after unilateral destruction of the trigeminal motor nucleus by kainic acid injection in order to evaluate the distribution of sensory and motor fibers in masticatory muscle nerves. The surviving axons were counted and their diameters measured, and the results were compared with data for control nerves. The diameters of the control masseter nerve fibers were bimodally distributed with peaks at 2-5 and 7-9 μm. The nerve fiber diameters on the injected side, i.e., afferent fibers, also showed a bimodal distribution with peaks at 2-4 and 6-9μm. On the other hand, the fiber diameter spectrum of the motor fibers, which was estimated from the loss of these fibers after kainic lesions, was unimodal within ranges of 1-16μm. Consequently, the largest fibers of the masseter nerve were estimated to be motor fibers. A comparison of the distribution of diameters and conduction velocities of the afferent fibers indicates that both primary and secondary spindle afferents are mostly included in the larger diameter group with the peak at 6-9μm.
The diameters of fibers of the common mylohyoid nerve trunk showed a bimodal distribution, similarly to those of the masseter nerve. However, the analysis of the peripheral branches of the mylohyoid nerve revealed that the largest afferents in this nerve were of cutaneous origin, since muscle afferents of the anterior digastric and mylohyoid muscles have small diameters. These findings suggest that muscle spindles are absent or few in these two suprahyoid muscles in the cat.View full abstractDownload PDF (6106K) -
Takashi NISHINO, Yoshiyuki HONDA1982 Volume 32 Issue 2 Pages 183-195
Published: 1982
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSThe effects of baroreceptor stimulation produced by a sudden rise in arterial pressure on respiratory pattern were studied at various levels of Paco2 and Pao2 in 8 anesthetized cats. A sudden rise in arterial pressure decreased both tidal volume and respiratory frequency. For a given increase in arterial pressure, the decrease in tidal volume was constant at all levels of Paco2 and Pao2 examined, whereas the decrease in respiratory frequency became progressively lower as the level of chemical drive increased, regardless of the type of chemical stimuli. Analysis of respiratory duration revealed that the decrease in respiratory frequency during baroreceptor stimulation was solely due to prolongation of expiration. These observations were obtained in the intact as well as in the vagotomized animals but were not seen after bilateral sinus nerve section. They suggest that the central respiratory mechanisms controlling respiratory frequency are directly involved in the reduction in respiratory frequency during baroreceptor stimulation.View full abstractDownload PDF (1088K) -
Tomoko KAGAWA, Masaji MOCHIZUKI1982 Volume 32 Issue 2 Pages 197-218
Published: 1982
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSThe non-linear partial differential equation for O2 diffusion was solved numerically in the three-dimensional red cell model by using the alternating-direction implicit method. The oxygenation rate factor of hemoglobin (Fs) was assumed to decrease as the O2 saturation (SO2) increases, as given by Fs=2.1 ×(1-S) 2 (sec-1·(mmHg) -1). The result obtained was compared with the solutions of the equations derived by Thews and Moll and also with those obtained from the sheet model. The oxygenation rate of the red cell largely depended on the diffusivity across the diffusion barrier around the red cell (η). When η=2.5 × 10-8 cm · sec-1·(mmHg) -1 was inserted into the present equation, the numerical solution showed a good correlation with the experimental data. When the sheet model was applied, the η value obtained from the same experimental data was about twice as great as that obtained in the disc model.
One of the characteristic features of the SO2-time curves of the red cell was the decrease in steepness at a high SO2 range, which has been thought to occur due to the decrease in the oxygenation rate of hemoglobin. Therefore, the difference of the actual PO2 in the red cell from the fictitious, so-called “back-pressure” which is evaluated from the O2 dissociation curve through the actual SO2 has been expected to become greater as the SO2 increases. The result obtained from the present equation revealed that the above PO2 difference became as great as 20 mmHg at the maximum point. In the solutions obtained from Thews' and Moll's equations, however, the slope of the SO2-time curve was not significantly reduced at a high SO2 range.View full abstractDownload PDF (1726K) -
Alec N. SALT, Teruzo KONISHI1982 Volume 32 Issue 2 Pages 219-230
Published: 1982
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSThe effects of amiloride on the cochlear responses in the guinea pig were compared with those produced by tetraethylammonium (TEA). Amiloride has been reported to reduce membrane permeability to sodium in a wide variety of ion-transporting epithelia. TEA has been documented to suppress the active potassium permeability increase during the repolarization phase of the action potential in mammalian excitable cells, and to reduce the resting potassium conductance in mammalian smooth muscle cells. Perilymphatic perfusion of 10-3 M amiloride or intravenous injection at a dose of 20 mg/kg suppressed the whole nerve action potential (AP) of the cochlea but did not significantly affect the cochlear microphonics (CM) or endocochlear potential (EP). Application of amiloride to endolymph by iontophoretic or perfusion techniques also produced no significant changes of CM and EP when compared with appropriate control procedures. Perilymphatic perfusion of 10-2 M TEA did not suppress CM or EP but the AP was reduced. Iontophoretic application of TEA to the endolymph caused a marked suppression of CM while the EP was significantly increased. The effects of endolymphatic TEA application are consistent with the concept that the normal EP recorded from scala media is the algebraic sum of a positive electrogenic potential and a negative diffusion potential, the latter component being sensitive to potassium permeability changes of the endolymph-perilymph barrier. Maintenance of normal cochlear microphonics also appears dependent upon the maintenance of normal potassium permeability properties of the endolymph-perilymph barrier. The functional importance of normal sodium permeability properties appears less certain.View full abstractDownload PDF (1130K) -
Masaji MOCHIZUKI, Hiroshi TAZAWA, Masakazu TAMURA1982 Volume 32 Issue 2 Pages 231-244
Published: 1982
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSThe CO2 content and pH of tonometered blood were measured in nine healthy subjects. The CO2 content in the whole blood (Cb) was found to be expressed by an exponential function of PCO2 including only one parameter (B) as follows:
Cb=1.15·B-2.548·PBCO2
The B value was specific to the sampled blood and ranged from 0.4 to 0.45 in the deoxygenated and from 0.45 to 0.52 in the oxygenated blood. The relationship between pH and log PCO2 was also expressed by using one characteristic parameter (D) as follows: for the deoxygenated blood.
log PCO2=2.144-D·(pH-7.045).
and for the oxygenated blood.
log PCO2=2.037-D·(pH-7.085).
The D values were in a range of 1.38 to 1.58. The linear relation between log [HCO-3] and pH was also expressed by using only one parameter. Next, between Cb and [HCO-3] obtained at the same PCO2 of 40 mmHg, a high correlation was observed: the regression line was given, independently of O2 saturation, by
Cb40=1.942·[HCO3-]40-3.193.
where [HCO3-] was expressed in mM. Using the above equations, it was possible to evaluate the approximate B and D values from a pair of pH and PCO2 measurements and subsequently to depict the CO2 dissociation curve as well as the buffer line in the true plasma.View full abstractDownload PDF (1167K) -
Yoshimi MIYAMOTO, Tatsuhiko TAMURA, Tadashi HIURA, Takao NAKAMURA, Jir ...1982 Volume 32 Issue 2 Pages 245-258
Published: 1982
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSTransitional changes in stroke volume, heart rate, and cardiac output resulting from head-up tilt were measured in healthy male subjects, using impedance cardiography. Respiratory frequency, tidal volume, ventilation rate, end-tidal O2 and CO2 tensions, O2 uptake, CO2 output, and exchange ratio were also determined breath-by-breath. When the subject was tilted upward from a supine to an upright position, the stroke volume was decreased while the heart rate was increased. The time required to attain the steady state was shorter in the stroke volume change than in the heart rate. In addition, since the heart rate was not increased so high as to be inversely related to the stroke volume, the cardiac output decreased by tilting upward. The ventilation rate remained almost unchanged within a tilt angle of 60° or so. Thus, both the O2 and CO2 fractions in expired air showed transitory changes. As the original body position was restored, the cardiac output was increased to the initial level, the tidal volume showing a transient increase. During the recovery process, PCO2 in expired air increased and PO2 decreased, showing that the change in cardiac output exceeded that in ventilation in quantity. The change in ventilation, moreover, preceded that of expired PCO2 by ca. 10 sec, suggesting that the enhancement of ventilation occurred through some agent (s) other than the chemical drive.View full abstractDownload PDF (1583K) -
Akira ARITA, Hideo HAYASHI1982 Volume 32 Issue 2 Pages 259-278
Published: 1982
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSHyperpolarizing responses of the somata of median giant fibers of crayfish were investigated under current clamp and voltage clamp conditions in normal saline. The responses consisted of a peak [mean ΔVm (peak)=-217mV] followed by a plateau (-107 mV), and could be classified into N-type and G-type. In the N-type cells, the current clamp I-V curve showed a transient phase to the peak. The phase corresponded to the negative slope region of the voltage clamp I-V curve. There was no negative slope region in the G-type cells. In the transient and the peak phases, the instantaneous I-V curves showed nonlinearity, and the shifts of the electromotive forces (ΔEMF) from the resting level were slightly negative or zero. In the plateau phase, however, the instantaneous I-V curve was linear and ΔEMF was large and positive (33.2 mV). The membrane resistance, which was larger (×2.3) at the peak than at the resting state, decreased (×0.23) gradually during the plateau phase.ΔEMF during the hyperpolarizing response consisted of two components: a fast component (1.7 msec) and a slow one (113 msec). The amplitudes of ΔEMF (27.4 mV) of these components in the depolarizing direction increased gradually, once the response had reached the peak. The fast and slow ΔEMF's attained 17.0 and 10.4 mV respectively at the end of 100 msec current pulse. It is shown that constant charge triggers the plateau process and that this threshold voltage-current curve is hyperbolic. It is a possiblity that the plateau is caused by membrane breakdown.View full abstractDownload PDF (2019K) -
KOZO HIRATA1982 Volume 32 Issue 2 Pages 279-291
Published: 1982
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSCardiac output (CO) and regional blood flow to various tissue were measured by means of γ-labeled plastic microspheres (15±3 μm) injected into the left ventricle during 30-min infusion of l-norepinephrine (NE: 4 μg/(kg·min)) or the same amount of saline (11μl/min per animal) in rats physically trained by 2-hr swimming in water of 32 (SW-32), 36 (SW-36), and 38°C (SW-38) for 10-11 weeks and in control (CT) rats. Body weight and skinfold thickness were significantly less in SW-36 and SW-38 than CT rats. The weights of heart and adrenal glands significantly increased in the trained rats in comparison with CT rats. The average weight of brown adipose tissue (BAT) was significantly greater in SW-32 and significantly less in SW-36 and SW-38 as compared with CT rats. Infusion of NE induced significant increases in oxygen consumption (Vo2), colonic temperature, heart rate, CO, blood flow to BAT, and mean blood pressure in anesthetized rats. The increases in Vo2 and CO were significantly greater in SW-32 and SW-36 than in CT rats. The increases in blood flow to BAT were significantly greater in SW-32, SW-36, and SW-38 than in CT rats. These results indicate that physical training per se enhances calorigenic response to NE supported by an increased cardiac output and blood flow to the dominant calorigenic tissues such as BAT in rats.View full abstractDownload PDF (1303K) -
Yoshiyuki SAKATA, Akio MORIMOTO, Yoshitaka TAKASE, Naotoshi MURAKAMI1982 Volume 32 Issue 2 Pages 293-297
Published: 1982
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSThe response of medullary temperature-responsive (TR) neurons to endogenous pyrogen (EP) was reduced remarkably by pretreatment with neuraminidase (1.0×10-3 unit) microinjected into the tissue adjacent to the recording neuron in rabbit brain. Sialic acidcontaining substances on the membrane of the TR neurons, which are split by neuraminidase, seem to play a role in the response to EP.View full abstractDownload PDF (487K) -
Yasushi KAWAUE, Yasuhiro TERANISHI, Juro IRIUCHIJIMA1982 Volume 32 Issue 2 Pages 299-301
Published: 1982
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSUsing an electromagnetic flowmeter, regional blood flow was measured at the carotid, celiac, superior mesenteric, renal, and iliac arteries in normal Wistar rats and spontaneously hypertensive rats anesthetized with pentobarbital sodium. The sum of the mean values of the flow rate normalized per 100 g body weight for all the arteries was similar for both groups. About a half of the sum was drained through the superior mesenteric artery in both groups. The normalized flow rate was similar for both rat groups for each artery excepting the renal artery where the flow rate was significantly greater in the hypertensive rats.View full abstractDownload PDF (293K) -
Takehiro YAHATA, Akihiro KUROSHIMA1982 Volume 32 Issue 2 Pages 303-307
Published: 1982
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSThe thermogenic response of brown adipocytes to glucagon was reduced by either thyroidectomy or adrenalectomy, while that to noradrenaline was not affected. Polyamines (spermine and spermidine) inhibited glucagon-induced thermogenesis of the cells. These results suggest that glucagon stimulates brown adipocytes under the influence of thyroidal and adrenal hormones, and that polyamines regulate the thermogenesis of brown adipocytes in an inhibitory way.View full abstractDownload PDF (521K) -
Ryuji MATSUO, Takashi YAMAMOTO, Yojiro KAWAMURA1982 Volume 32 Issue 2 Pages 309-313
Published: 1982
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSExtracellular antidromic and orthodromic responses of the salivatory neurons in the medulla oblongata which send preganglionic parasympathetic fibers to the submandibular gland were recorded in rabbits. The mean of conduction time from the subnucleus caudalis of the spinal trigeminal nucleus to the salivatory neurons was within a range of 4.8-6.4 msec, suggesting oligosynaptic but not monosynaptic connections between the first order trigeminal sensory nucleus and the salivatory neurons.View full abstractDownload PDF (545K) -
Minoru INAZAWA, Tsuguhisa EHARA, Jun-ichi HASEGAWA1982 Volume 32 Issue 2 Pages 315-319
Published: 1982
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSLowering [Na]o, down to 50% of the normal concentration only slightly reduced the overshoot of the Ca-dependent slow action potentials in K-depolarized guinea-pig papillary muscles. The maximum rate of rise of the action potential also appeared to be independent of [Na]o. These results suggest that Na ions do not play a major role as charge carriers responsible for generation of the slow action potentials in this tissue.View full abstractDownload PDF (514K) -
Ken'ichi MATSUNAMI1982 Volume 32 Issue 2 Pages 321-325
Published: 1982
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSThe uptake of [14C]-2-deoxy-D-glucose (2DG) into the heart muscle of the monkey was investigated. Increased 2DG uptake was observed in ventricular, trabecular and papillary muscles of the left ventricle. However, it was very small in the right ventricular and papillary muscles. The atrium or ascending arterial wall showed little 2DG uptake.View full abstractDownload PDF (3268K)
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