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Volume 25 (1975)
- Issue 6 Pages 665-
- Issue 5 Pages 563-
- Issue 4 Pages 401-
- Issue 3 Pages 241-
- Issue 2 Pages 93-
- Issue 1 Pages 1-
Volume 25, Issue 2
Displaying 1-12 of 12 articles from this issue
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Tsukasa ONO, Hiroshi TAZAWA1975 Volume 25 Issue 2 Pages 93-107
Published: 1975
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSA new reaction apparatus combining a microscope and a photometric device was developed for kinetic studies of a single red cell. A monolayer of red cells was placed in a closed reaction cuvette set on a microscope stage, a light beam of 5 to 10μm in diameter was directed into one of the red cells, and the light transmission change in the cell was analyzed. The light beam with a wavelength range shorter than 460nm was made by placing a narrow iris diaphragm in the light path. The space in the cuvette prevented the red cells from drying thereby providing favorable physiological conditions during measurements. The cuvette was filled with reagent gas mixtures of O2, CO2, and N2 which came in contact with the red cells. Transmission change due to the reaction was detected separately at two wavelengths of 418 and 402nm by means of two photomultipliers mounted on the microscope. The linearity was tested by comparison between SO2 measured with a Van-Slyke apparatus and the microphotometer. Both SO2 measurements agreed well with each other, but the latter was about 3% greater than the former at around 50% SO2. Using this apparatus the oxygenation and deoxygenation velocities were measured over an entire O2-saturation range. The velocity factors showed good agreement with those obtained by using conventional flow methods.View full abstractDownload PDF (1412K) -
Yoshio ISHIMA, Katsuto YUMOTO1975 Volume 25 Issue 2 Pages 109-122
Published: 1975
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSGiant axons of crayfish were excitable in sodium-free external media containing hydrazinium, hydroxylamine, or guanidinium ions. Action potentials in these solutions were slightly smaller in size and a little longer in duration than those in standard Harreveld's solution. The resting potential was not affected in hydrazine or in hydroxylamine saline, but decreased in guanidine saline. The membrane potential at the peak of the spike (V) was plotted against the univalent cation concentrations in the external medium. The relationship could be expressed by an equation: V=V0+(RT/F) ln ([Na]+α[C]), where V0 and α are constants and [Na] and [C] are concentrations of sodium ions and the tested cations, respectively. The parameter α was considered as an indicator to express the ability of substitution of the cation for sodium ion. The order of the ability of the substitution was: Hydroxylamine>Hydrazinium>Guanidinium>Choline.View full abstractDownload PDF (1459K) -
Tetsuji MATSUURA1975 Volume 25 Issue 2 Pages 123-133
Published: 1975
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSThe relation of the threshold of the late receptor potential (late RP) and ERG b-wave with the rhodopsin concentration in the rod outer segments of an isolated bullfrog retina were studied by simultaneous recordings of electrical responses and spectral change. The curve indicating log threshold rise of the late RP with the decrease of rhodopsin showed two phases separated by a kink, which was found at 50% rhodopsin concentration; the b-wave threshold, however, was linearly related to rhodopsin concentration. From the intensity response curves (IR curves) at various rhodopsin concentrations, the amplitude decrease of both waves following bleaching light adaptation was compared and the mode of the conversion from the late RP to the b-wave was discussed.View full abstractDownload PDF (2479K) -
Saburo HOMMA, Muneaki MIZOTE, Shiro WATANABE1975 Volume 25 Issue 2 Pages 135-146
Published: 1975
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSThrough intracellular observations of the cat spinal motoneuron both mono-and polysynaptic reflex arcs were shown to participate in repetitive activation of stretch reflex. Experiments were performed on 25 cats anesthetized by intraperitoneal (i.p.) injection of 3cc/kg of a mixture of 1% chloralose and 10% urethane. Driving of the motoneuronal discharges accomplished by electric stimulation (16-100Hz) of the gastrocnemius lateralis and medialis nerves.
Repeated electric stimulation of muscle nerves elicited monosynaptic ‘vibratory’ EPSPs and a polysynaptic ‘augmenting’ EPSP in the moto-neuron.
The firing of the motoneuron occurred when a temporal summation of the ‘vibratory’ EPSPs was sufficiently obtained. The discharge frequency of motoneuron, MNf, was expressed as a product of electrostimulus frequency, Sf, and reciprocal of an integer, n, i. e. MNMf=(1/n)Sf. An increase in the stimulus intensity resulted in a diminution of the vibratory EPSP and a remarkable increase of n. This was assumed to be due to an inhibitory process produced by the Group II fibers.
The minimum value of integer n was always a determinant factor for the maximum value of MNf which was referred to as the ‘preferred’ frequency of the motoneuron.
Long-lasting electric stimulation of muscle nerves was followed by a more remarkable recruitment of the augmenting EPSP which made the motoneuron attain its critical threshold of firing. Motoneuronal spikes elicited by such a large augmenting EPSP were not locked to the Ia impulses. Unlocked spikes were observed only in a later stage of electric stimulation of Ia fibers.View full abstractDownload PDF (5483K) -
Hiromi TOKURA, Fumie HARA, Morihiko OKADA, Fumio MEKATA, Wataru OHSAWA1975 Volume 25 Issue 2 Pages 147-152
Published: 1975
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSThermoregulatory responses in four male adult Japanese macaques and four male adult crab-eating macaques, weighing 6-12kg and 6.2-8kg, respectively, were compared at ambient temperatures (Ta) ranging from 5° to 25°. The average values±S. E. for some physiological measurements made at Ta of 25° in the Japanese macaque and the crab-eating macaque, respectively, were as follows: resting metabolic rate; 47.6±5.0 and 42.5±1.7W/M2; tissue conductance; 11.9±0.8 and 8.9±0.8W/M2/°; respiratory evaporative heat loss; 4.1±0.3 and 3.2±0.5W/M2; rectal temperature; 38.6±0.1 and 37.4±0.2°; mean skin temperature; 34.0±0.3 and 31.2±0.1°. When Ta was lowered stepwise from 25° to 20, 15, 10, and 5° successively, and maintained constant at each temperature level for 1 hr, metabolic heat production gradually increased in both species. When Ta was lowered from 10° to 5°, the crab-eating macaque did not show further increase in heat production and the result was a loss of thermal equilibrium with rectal temperature continuing to fall. On the other hand, the Japanese macaque maintained thermal balance even at Ta of 5°. Tissue conductance, which was significantly higher in the Japanese macaque than in the crab-eating macaque at Ta of 5, 15, and 25°, decreased in both species as Ta was lowered from 25° to 15 and 5°. The specific differences in thermoregulatory responses are considered to be adaptational, relative to the natural habitat of the two species studied. ReceivedView full abstractDownload PDF (675K) -
Takuro OSA, Takashi KATASE1975 Volume 25 Issue 2 Pages 153-164
Published: 1975
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSA comparative investigation of the longitudinal and circular muscles in the pregnant rat uterus (10-15days) was made by means of electrical and mechanical recordings. The response of the circular muscle strip was characterized in the following respects: application of stretch caused acceleration of spontaneous activity that was greater in extent than in the longitudinal muscle strip; tetanic contraction was not produced by repetitive stimuli in the range of 0.1-5Hz; slow potential was dominant in the circular muscle cells. The longitudinal contraction of the uterine segment occurred in synchronization with the change in the intraluminal pressure. Either the longitudinal stretch or the increase in the intraluminal volume caused the acceleration of synchronized activity. Stimulation of the longitudinal muscle caused membrane response in the circular muscle cells and vice versa, suggesting electrical interference between longitudinal and circular muscle cells.View full abstractDownload PDF (8085K) -
Hiromichi NOMURA1975 Volume 25 Issue 2 Pages 165-173
Published: 1975
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSEffects of some chemicals, which are known as inhibitors of Ca2+-dependent ATPases, on the water receptor of the frog tongue were examined by using single fungiform papilla preparations. When a sufficient amount of ruthenium red, quinacrine hydrochloride, ethacrynic acid or 2, 4-dinitrophenol was added to the standard stimulating solution.(5mM CaCl2+100mM NaCl), which has been shown to stimulate sufficiently the water receptor of the frog tongue, no neural response was elicited. The concentrations necessary for 50% inhibition were approximately 3×10-6M for ruthenium red, 1×10-5M for quinacrine hydrochloride, 1×10-3M for ethacrynic acid and 2×10-4M for 2, 4-dinitrophenol. Organic mercurials, mersalyl acid and p-chloromercuribenzoic acid, had no effect on the neural response, but repeated application of these chemicals led to a permanent depression in receptor activity. Ouabain had no effect on either the neural response or receptor activity. These observations indicate that the receptor molecule of the frog water receptor has a similar property to that of the Ca2+-dependent ATPase of red-cell membrane in respect to the susceptibility to inhibitors.View full abstractDownload PDF (1209K) -
G. H. PARKER, J. C. GEORGE1975 Volume 25 Issue 2 Pages 175-184
Published: 1975
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSIn an attempt to determine the functional role of the component broad white and narrow red fibre types during activity, the pectoralis muscle of the adult pigeon (Columba livia) was electrically stimulated in situ after anaesthetizing the birds with sodium pentobarbital. For examination of the effect of short term exercise, the pectoral muscle of one side was stimulated through the innervating brachial plexus, using an electronic stimulator for 1hr, and a biopsy sample was taken from the stimulated muscle. The stimulation was resumed for 17hr more with additional doses of anaesthesia, and a muscle sample was taken after the decapitation of the birds in the long term experiment. Muscle samples from non-stimulated pigeons under identical conditions served as control. Fixed and frozen sections were made from the samples and were stained with Periodic Acid-Schiff's reagent for the demonstration of glycogen, while additional frozen muscle sections were stained with Fettrot 7B according to Pearse, A.G.E.(1960) for the demonstration of neutral lipids in the specimen. Thus histochemical examinations were made to study effects of short and long term exercises on energy stores in skeletal muscles.
Short-term stimulation resulted in a selective depletion of intracellular glycogen stores from white fibre populations whereas prolonged long term stimulation resulted in the resynthesis of glycogen within these fibres and a concomitant reduction in the intracellular fat and glycogen reserves in most red fibres. It is postulated that during flight the white fibres indulge only in brief bursts of intense phasic activity such as in quick take-off, rapid accelerations or sudden manoeuvres and utilize glycogen as fuel whereas the red fibres perform sustained activity as in cruising flight and metabolize chiefly fat.View full abstractDownload PDF (9273K) -
Takuro OSA1975 Volume 25 Issue 2 Pages 185-199
Published: 1975
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSEffects of external ions (Na, K, Mg) on the recovery from K-contracture of the pregnant rat myometrium were investigated in Ca-free media. Relaxation was faster, when the external concentration of Na and K ions was higher. The time course of relaxation within a limited range of 60-20% of the mechanical output followed a single exponential function. The rate of relaxation, given by the reciprocal of the period during which the contraction decayed to 1/e, was 0.3-0.5min-1 at 34-35°C in isotonic Na solution. Low temperature caused prolongation of the relaxation, and the activation energy estimated on the rate of relaxation was 3-4kcal·mol-1. Relaxation became faster when Mg (0.5-20mM) was added to the relaxation media. Relaxation in isotonic K media was slower than in isotonic Na media, and the addition of Mg caused a slight acceleration of the relaxation. Low temperature caused an acceleration of the relaxation, irrespective of the presence or absence of external Mg ions. In low K media, where K ions were replaced by isosmolar sucrose, addition of Mg caused a significant acceleration of the relaxation. Activation energy ranged between 13-15kcal·mol-1 in the solutions containing Mg. This favors the existence of a relaxing system in pregnant rat myometrium that is Mg-and metabolismlinked.View full abstractDownload PDF (2633K) -
Hikaru SUZUKI, Hirosi KURIYAMA1975 Volume 25 Issue 2 Pages 201-215
Published: 1975
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSAt any stage of gestation, low concentrations of PGE2 increased the frequency and number of spikes in a train discharge without any marked change of the membrane potential. An increased concentration depolarized the membrane and produced continuous spike generation. A further increase in concentration of PGE2 produced a depolarization block of spike generation. The sensitivity of the myometrium to PGE2 was markedly increased during the progress of gestation so that at the late stage of gestation, the sensitivity was more than 100 times greater than at the early stage. The longitudinal muscle showed a higher sensitivity to PGE2 than the circular muscle. However, both muscles showed a similar sensitivity to oxytocin. In the longitudinal muscle, desensitization to PGE2 occurred more quickly than to oxytocin. When PGE2 produced a slight depolarization of the membrane, the membrane resistance was increased. However, when the membrane potential was displaced to the control level by applying a hyperpolarizing current, the membrane resistance was slightly reduced. Displacement of the membrane potential to the level before drug application restored spike generation. However, the membrane resistance was still reduced. In Na-deficient Locke solution or in Ca-free Mg-Locke solution, the depolarization induced by PGE2 was suppressed but not suppressed by, in K-deficient Locke solution.View full abstractDownload PDF (1953K) -
Yoshio EBINA, Nobukata NAGASAWA, Yasuo TSUKAHARA1975 Volume 25 Issue 2 Pages 217-226
Published: 1975
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSTo clarify the formation process of acid metarhodopsin in the cephalopod rhodopsin cycle, changes in the difference spectrum of squid (Todarodes pacificus) rhodopsin in acid (pH 5.7, or pH 6.1) and alkaline (pH 10.2) solutions were studied at various temperatures by applying the flash photolytic technique. An intermediate with an absorption maximum at about 475nm was transformed from lumirhodopsin prior to the formation of acid metarhodopsin independently of the pH of the solution. In alkaline solution, some of the converted acid metarhodopsins were then transformed to alkaline metarhodopsins. The conversion of lumirhodopsin to acid metarhodopsin seemed to be a first-order chain reaction.View full abstractDownload PDF (1321K) -
Saburo MATSUBARA1975 Volume 25 Issue 2 Pages 227-240
Published: 1975
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSThe effect of lowering temperature on the resting tension of frog's striated muscle was studied at various sarcomere lengths, using whole muscle, single-fibre and skinned-fibre preparations. And the temperature coefficient of tension, β=(1/P)(dP/dT)(P, tension; T, temperature) was investigated. In whole sartorius muscles in Ringer solution, β was negative over the whole range of sarcomere lengths investigated. In the presence of 2mM procaine the rubber-like thermoelasticity (β>0) was revealed at medium lengths. Atshorter (>2.3μm) andlonger (>2.7μm) lengths, β stayed negative. In single muscle fibres suspended in Ringer solution with 2mM procaine, β was positive over a wider range of lengths (2.3-3.4μm), and the peak positive value of β was obtained at the length of 2.6μm. In skinned fibres suspended in a relaxing solution, β stayed positive up to the length of 4.2μm, and the peak value of β was obtained at the length of 3.0μm which was considerably longer than in single fibres. The results substantiated A.V. Hill's view on the thermoelasticity of the muscle; there are components with positive β(contractile apparatus) and those with negative β(connective tissue and sarcolemma), and at high elongations the positive coefficient is masked by the increasing importance of the negative coefficient.View full abstractDownload PDF (1639K)
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