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Volume 18 (1968)
- Issue 6 Pages 687-
- Issue 5 Pages 563-
- Issue 4 Pages 403-
- Issue 3 Pages 267-
- Issue 2 Pages 145-
- Issue 1 Pages 1-
Volume 18, Issue 5
Displaying 1-12 of 12 articles from this issue
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A. K. SENGUPTA, M.O. PRAKASH, A. GHOSE1968 Volume 18 Issue 5 Pages 563-569
Published: 1968
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSDownload PDF (708K) -
Yasu-Ichiro FUKUDA1968 Volume 18 Issue 5 Pages 570-575
Published: 1968
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSThe well documented Ca contracture or Ca rigor of the frog's ventricle due to excess Ca in the medium was found to be accompanied by rapid regular electrical oscillations (“rigor oscillation”).Not only an increase in the Ca content of the ventricle beyond a certain limit, but also the excitation conducted from the auricle were found necessary for the induction of the rigor.The rigor was interrupted by the A-V block due to hypoxia during the state of rigor, and reappeared after recovery of the conduction.
The K in the medium antagonized the rigor by inhibiting the increase in the cellular Ca content.View full abstractDownload PDF (2689K) -
Fumio ITO1968 Volume 18 Issue 5 Pages 576-589
Published: 1968
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESS1. Afferent discharges from the tendon receptors in the pelvic and tibial ends (with some of knee joint capsules) of the frog's sartorius muscle were recorded from the 8th and 9th dorsal roots respectively.
2. In 45 out of 54 receptors tested, small spike discharges with conduction velocities of from 5 to 35 m/sec (25-28°C) occurred with thresholds from 0.5 to 2g tensions during isometric contractions of the muscle, and the number and frequency of the discharges increased with increases of the tension.The remaining 9 receptors were characterized by large spikes with conduction velocities from 35 to 45m/sec and by rapid adaptation.
3. During shortening of the muscle against loads, all the receptors responded with only one discharge at the peak of tension development d ue to acceleration of the weight by the shortening muscle.
4. During muscle stretch at constant velocities, 38 receptors (31 smallspike
and 7 large-spike) discharged phasically during the dynamic phas e of stretch by 4mm from initial lengths of more than+6mm.The other 14 receptors (11 small-spike and 3 large-spike) responded to stretch by 4mm from initial lengths of more than+4mm.The remaining two receptors were characterized by sustained discharges during muscle stretch of 4mm from +2mm initial length.The static index of the sustained discharge was independent of the velocity of the stretch and the static sensitivity was 3.73 impulses/sec/mm in the mean.Various dynamic indexes were observed with different velocities of muscle stretch or with different initial muscle lencrths.
5. It was suggested that these functional properties of the tendon receptors may be resemble to those of the leaf-like muscle receptors, and that the activities may be attributed to an inverse myotatic reflex by which excessive stresses to the muscle are eliminated.View full abstractDownload PDF (1368K) -
Fumio ITO1968 Volume 18 Issue 5 Pages 590-600
Published: 1968
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESS1. The properties of leaf-like receptors were studied by means of an analysis of the discharges recorded from the 9th dorsal root in a frog sartorius muscle-nerve preparation.
2. During isometric contraction of the muscle, about 70% of the discharges from the receptors occurred at the falling phase of the tension curve, and 30% occurred at the rising phase.
3. During muscle shortening against loads, the leaf-like receptors were characterized by their responses in both the first and second upward tension
4. With muscle stretching at constant velocities, the static index increased linearly with increases of the initial length.The static sensitivity ranged from 2.2 to 4.5impulses/sec/mm.The dynamic index was dependent upon the velocity of stretching and on the initial length.
5. The possibility that the excitability of the receptor may resemble that of the tendon receptor was discussed.The different discharge patterns from the two kinds of receptors during various mechanical stimulations may be due to the differences of contractile elements acting on their receptors and also to different visco-elastic properties of the tissues embedded with them. deflections.View full abstractDownload PDF (1104K) -
Fumio ITO1968 Volume 18 Issue 5 Pages 601-608
Published: 1968
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESS1. The effects exerted on muscle spindles in the frog sartorius during contraction of the extrafusal muscle fibers were studied in comparison with those during contraction with participation of the intrafusal fibers.
2, The discharges were suppressed without appreciable early discharges during the isometric twitch and tetanic contractions of the extrafusal muscle fibers, whilst some early discharges appeared during the contractions with participation of the intrafusal muscle fibers.
3. During shortening of the extrafusal muscle fibers against loads, the spindle discharges were facilitated only at the second upward deflection of the muscle tension.The shortening with participation of the intrafusal muscle fibers resulted often in a few additional discharges at the first upward deflection.
4. These results suggest that the early discharge of the spindle receptor may be due to contractions of the intrafusal muscle fibers (a serial force with the receptor) in relation to those of the extrafusal muscle fibers (a parallel force).View full abstractDownload PDF (798K) -
Tsutomu HIROSHIGE, Haruhiko KUNITA, Chikashi OGURA, Shinji ITOH1968 Volume 18 Issue 5 Pages 609-619
Published: 1968
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSBy use of intrapituitary microinjection method, CRF activities of posterior pituitary hormones and several biologically active amines were examined which were reported to exist in relatively high concentrations in both the hypothalamic and the neurohypophysial tissues.It was found that none of the neurohypophysial hormones were effective at the doses used when placed directly in the adenohypophysial tissue, whereas intra-neurohypophysial injection of lysine vasopressin evoked a significant release of ACTH.These results strongly suggest that vasopressin is not CRF itself but causes ACTH release through mobilization of the neurohypophysial CRF.
Among other amines examined, norepinephrine and serotonin, when injected into the anterior pituitary lobe, were devoid of CRF activity, whereas epinephrine and histamine in relatively large amounts were found potent in eliciting a significant ACTH release.These findings were discussed in relation to the possible role played by these amines in the regulation of ACTH release.View full abstractDownload PDF (1124K) -
Chosaburo YAMAMOTO, Nobufumi KAWAI1968 Volume 18 Issue 5 Pages 620-631
Published: 1968
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESS1.Electrical activities of the thin sections prepared from the guinea pig hippocampus were studied in vitro in artificial media of modified composition.
2.When Cl ion in the medium was substituted with large anions (such as propionate ion), a train of afterdischarge consisting of large spike potentials and superposed on a slow wave was elicited by a single shock applied to the section.The spontaneous discharges were observed as well.
3.The discharge propagated through the slice at a speed of 1 to 3cm/sec.
4.A complete silence of electrical activities (post-afterdischarge extinction) followed the afterdischarge in some stage of the experiments.
5.The discharge was augmented by phenobarbital sodium in low concentrations but suppressed in high concentrations of the anesthetic.
6.The discharge was found to originate in the dentate gyrus.
7.It was concluded that the discharge was akin to the seizure discharge. Its generation in the present experimental condition was considered due to suppression of inhibitory mechanisms.View full abstractDownload PDF (2731K) -
K. OHARA, Jerry L. NEWTON1968 Volume 18 Issue 5 Pages 632-641
Published: 1968
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSAn ultramicro open end capillary glass electrode for sodium determination in biological fluids was developed based on a new design.The characteristics of the electrode are as follows:
1) The minimal amount of test solution required for an estimation was 0.044 of a microliter, but even smaller electrodes may be constructed without difficulty.
2) The open end capillary tubes were inserted into sweat ducts and glands and Na ion concentration of the sweat determined directly as it was being produced.
3) Continuous recording of Na ion content of the test solution is possible as the solution flows past the ion sensitive membrane in the capillary.
4) The accuracy of determination is greatly increased by readjusting the electrometer with a standard solution after the circuit is completed, especially when the electrode is applied to a living body for sampling and direct measurement.
5) In spite of the small size of the electrode the reproducibility of readings made on standard NaCl solutions in the range of concentrations of biological fluids was found to be satisfactory in respect to both intraelectrode and inter-electrode fluctuations.View full abstractDownload PDF (765K) -
Isao HANAWA, Katsuhiko MATSUMURA, Tetsuji MATSUURA1968 Volume 18 Issue 5 Pages 642-654
Published: 1968
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESS1. The early receptor potential (early RP), which results from very intense photo-stimulation of the vertebrate eye, has been investigated in isolated pre-parations from the bullfrog's eye.All the preparations were placed as a septum separating the solutions in the apparatus.
2. The early RP of the retina with the pigment epithelium intact was more resistant to light adaptation than that of the retina alone, and its ampli-tude declined much more readily in the anaerobic than in the oxygenated condition. This clearly suggests that the pigment epithelium is necessary for the fast and sufficient regeneration of the visual pigments and that it requires oxygen to attain maximal activities.
3. Increasing the potassium concentration on both sides or the scleral side of the retina alone, the amplitude of the early RP was enhanced and the ratio of heights of positive and negative phases was decreased, whereas on the vitreous side the amplitude was increased, but the ratio remained unchanged. On the basis of these results it is proposed that an enhancement of the re-sponse is due to an increase of the transretinal electrical conductivity and a decrease in amplitude of a depolarizing potential which is probably elicited from the cell membrane of outer segments.
4. The early RP of retinal photoreceptors was not affected by a dc current across the retina, but the pigment epithelium-choroid complex generated a new slow response by an intense light flash under polarized condition.View full abstractDownload PDF (1369K) -
Isao HANAWA, Katsuhiko MATSUMURA, Tetsuji MATSUURA1968 Volume 18 Issue 5 Pages 655-664
Published: 1968
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESS1. The effects of alum on the early receptor potential (early RP) have been investigated with the isolated frog retina deprived of the pigment epithelium.
2. An application of alum on the receptor side of the retina produced irreversible changes in amplitude, peak latency of the negative phase, andratio of heights of positive and negative phase (shape quotient).
3. Small ozses of alum increased the early RP in amplitude and peak latency, but decreased in shape quotient.
4. Large doses of alum decreased the response in amplitude, peak latency and shape quotient, though all the rhodopsin remains in the outer segment. These findings clearly suggest that the early RP is closely related to the highly ordered structure of the outer segments.
5. The replacement of sodium chloride in the bathing solution with potassium chloride revealed no effect on the shape of the response of the tanned retina.
6. The evidence that changes in amplitude induced by an application of alum are always associated with a constant decrease in the shape quotient suggests that the cornea-negative phase of the response consists of a corneanegative component and a cornea-positive one. This cornea-positive component is probably generated by a conductance change in the membrane of outer segments.View full abstractDownload PDF (3450K) -
Jiro GOTOH, Masakatsu MOMIYAMA1968 Volume 18 Issue 5 Pages 665-672
Published: 1968
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESS1. By using the linked method, the electric field of the chicken brain was observed under restrained conditions to determine the presence of a dipole.
2. One of the two foci of phase reversal observed was between Le. 1-2 and Le. 3-4, or between Le. 1'-2' and Le. 3'-4', and the other was between Le. 8-9 and Le. 9-10, or between Le. 6'-7' and Le. 7'-8', both in unanesthetized and anesthetized chickens.
3. According to the dipole hypothesis concerning the origin of the electro-encephalogram, one dipole was present under these foci of phase reversal, or at electrode position P.2 or P.2:9 or 7.5mm frontal to the bregma and 3mmlateral to the median line, and the other one at electrode position P. 9:3mm frontal to the bregma and 6mm lateral to the median line.
4.In anesthetized chickens, however, a dipole seemed to be present under electrode position P.7:7.5mm frontal to the bregma and 6mm lateral to the median line.
The authors are deeply grateful to Professor K. TAKAGI, Department of Physiology, Faculty of Medicine, Nagoya University, for his kind advice. Ac-knowledgment is also made to Professor S. SAKASEGAWA, of Nippon Veterinary and Zootechnical College, who has reviewed the expression of this manuscript.View full abstractDownload PDF (786K) -
Kazushige SAKAI, Keigo YASUDA, Koroku HASHIMOTO1968 Volume 18 Issue 5 Pages 673-685
Published: 1968
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSThe mechanism responsible for the postocclusive vasoconstriction of the renal artery of dog was analyzed by pharmacological evaluation.
The renal circulation responded variably animal by animal after the release of occlusion.Among 36 nontreated dogs, the vasoconstriction, i. e., “reactive ischemia”, the vasodilation, i. e., “reactive hyperemia”, and no change in the vascular response, i. e., “dumb response” were obtained after 1 minute occlusion in 53, 33 and 14 per cent respectively. The number of the reactive ischemia among 9 reserpinized animals diminished to 33 per cent, while the number of the reactive hyperemia and dumb response increased to 44 and 23 per cent respectively.
The reactive ischemia was blocked completely by phenoxybenzamine (α-adrenergic blocking agent) treatment, while this phenomenon was potentiated remarkably by the treatment of dipyridamole (adenosine deaminase inhibitor). Dipyridamole treatment potentiated also vasoconstrictory response of adenosine, AMP and noradrenaline.
In cases of absence of the postocclusive vasoconstriction, noradrenaline or adenosine infusion or successive infusions of both substances converted the vascular response to the reactive ischemia, while AMP or angiotensin infusion did not modify the postocclusive vascular response at all.
These results imply that catecholamine-adenosine system would play a dominant role in the mechanism of the postocclusive vasoconstriction of the renal artery.View full abstractDownload PDF (1185K)
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