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Volume 27 (1977)
- Issue 6 Pages 687-
- Issue 5 Pages 525-
- Issue 4 Pages 391-
- Issue 3 Pages 267-
- Issue 2 Pages 135-
- Issue 1 Pages 1-
Volume 27, Issue 5
Displaying 1-9 of 9 articles from this issue
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Seiki HORI, Masaharu OHNAKA, Keizo SHIRAKI, Junzo TSUJITA, Hisato YOSH ...1977 Volume 27 Issue 5 Pages 525-538
Published: 1977
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSThe aim of this research is to compare the physical status, basal metabolism and some other physiological characteristics between native Thai in Bangkok, Thailand, and native Japanese in Japan, and discuss the results regarding acclimatization to tropical climate. Measurements of the Thai were made in September in Bangkok, while those of native Japanese were done in August at Nishinomiya (Japan). The subjects were adult males (20-22 years old) in both cases. Physically the Thai are generally a little shorter and more slender than Japanese in the mean value. The mean skinfold thickness for Thai was 8. 4mm, which is significantly less than that of Japanese (11. 0mm). The mean oral temperature measured under basal conditions was the same between both subject groups. The Thai showed a slightly lower basal metabolism per unit body surface, and mean skin temperature measured in a similar environmental condition was lower for Thai than for Japanese. The results of anthropometric measurements and physiological characteristics measured were discussed in view of physiology of acclimatization to tropical climate.View full abstractDownload PDF (1459K) -
Yasuo TANAKA, Atsushi ASANUMA, Keiji YANAGISAWA, Yasuji KATSUKI1977 Volume 27 Issue 5 Pages 539-549
Published: 1977
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSPrecipitation of cobalt ions and iontophoretic marking by Alcian Blue were utilized in examination of physiological properties of the subtectorial space in the guinea pig cochlea. Cobalt ions injected into the scala media were sulfurated and observed as a black precipitation in cross sections. Precipitation was seen on the upper and the lower surface of the tectorial membrane, and on the reticular membrane. Alcian Blue was the most suitable dye for marking in the organ of Corti. Recording sites of potentials in the subtectorial space were identified by Alcian Blue marking. The potentials were similar to those measured in the scala media. These facts verify that the subtectorial space communicates with the scala media through the outermost margin of the tectorial membrane. Thus the sensory hairs of hair cells are bathed in the endolymph of high potassium concentration, and the condition for optimum sensitivity of their receptor function is maintained.View full abstractDownload PDF (6189K) -
Kanae YAMASHITA, Takuji TAKAGI, Ken HOTTA1977 Volume 27 Issue 5 Pages 551-564
Published: 1977
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSIn order to clarify the Ca2+ mediated regulatory mechanism of vascular smooth muscle, the correlation between Ca2+ movements in the cell and mechanical response was investigated using isolated rat aorta and bovine basilar artery. K+ induced contraction of vascular smooth muscle required Ca2+ in the medium, and the contraction was always associated with a large increase in Ca2+influx. In the absence of external Ca2+, norepinephrine (NE) or serotonin (5HT) induced rapid contraction of the aorta and basilar artery, respectively. Caffeine (20 mm) also induced tension in the absence of Ca2+.
The results obtained in these experiments suggest that at least four kinds of calcium exist in bound from in the cell, i. e., (1) loosely and (2) tightly bound calcium on the external surface of the cell membrane, (3) calcium localized in the internal surface of the cell membrane and (4) calcium stored in the intracellular store site, such as the sarcoplasmic reticulum. The intracellulary stored calcium, both (3) and (4), which can be mobilized by the action of certain drugs (NE, 5HT or caffeine), probably plays an important role for the regulation of the mechanical activity of vascular smooth muscle.View full abstractDownload PDF (3723K) -
T. F. HUANG1977 Volume 27 Issue 5 Pages 565-576
Published: 1977
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSElectrical stimulation of the fastigial nucleus produced a pressor response with cardiac arrhythmia in cats. The arrhythmic response was abolished by tetrodotoxin (3μg/kg, i. v.), atropine (0.5 mg/kg, i. v.) or vagotomy, and suppressed slightly by propranolol or verapamil (0.5-1.0 mg/kg, i. v.). It was not abolished by the carotid sinus nerve section. The effects of the drug suggest that arrhythmia seems to be due to an interplay of sympathetic and parasympathetic influences with the latter effect predominating. The pressor and arrhythmic response to stimulation of the fastigial nucleus was increased by stimulation, and decreased by lesion of the posterior hypothalamus, indicating that some connection between the two structures exists.View full abstractDownload PDF (17243K) -
Issei SEYAMA1977 Volume 27 Issue 5 Pages 577-588
Published: 1977
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSThe resting membrane potential of S-A node cell was investigated by observing the response of the membrane potential to change in [K+] o or [Cl-] o under the presence or absence of Na ion. The slope of the change in membrane potential per decade change in [K+] o increased from 12.3 to 44 mV by removal of Na ion from the external medium, suggesting an extensive contribution of Na ion to the resting membrane potential. To determine the relative conductance between Na and K ions, Cl ion in Tyrode solution was substituted with SCN ion, which is 2.1 times more permeable than Cl ion, in order to eliminate the contribution of Cl concentration cell to the resting membrane potential. The contribution of the Cl ion to the resting membrane potential could be examined only in Na-free medium. Acetate ion has been reported to be 0.5 times less permeable than Cl ion. The replacement of Cl ion by acetate ion in various proportions caused a transient depolarization. The slope of this transient depolarization per decade change of [Cl-] o between 10 to 100mm was determined to be-6.8mV.
Under the assumption that the resting membrane potential could be determined by the parallel concentration cells for Na, K and Cl, relative conductance ratio between K, Na and Cl was calculated to be 1: 0.58: 0.15.View full abstractDownload PDF (1066K) -
Saburo MATSUBARA, Koscak MARUYAMA1977 Volume 27 Issue 5 Pages 589-600
Published: 1977
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSResting length-tension relation was studied in glycerinated preparations of frog semitendinosus and atrial muscles.The sarcomere length was measured by using either the light diffraction method or photomicrographs. When the glycerinated preparation was treated with 1N NaOH solution and subsequently with 2% SDS solution, the resting tension decreased. In glycerinated semitendinosus muscle the resting tension decreased to below 20% of the value before treatment. However, the glycerinated atrial muscle retained more than 50% of its resting tension in spite of such biochemical treatment.
The thermoelasticity of the muscle, which was represented by β(β=1/P0·dP/dT, where P0: resting tension at 15°C, P; tension, T; temperature), was determined. Glycerinated semitendinosus and atrial muscles, which were treated with 0.6M KCl, showed negative β at all sarcomere lengths. However, when the glycerinated muscle was treated with both alkali (1N NaOH) and SDS solution, β at the shorter length became positive (i.e., a rubber-like property).
Since connectin survived the biochemical treatment(either NaOH or SDS), it was concluded that the fraction of resting tension, which remained in spite of the biochemical treatments, might be due to the connectin.View full abstractDownload PDF (3674K) -
EFFECTS OF NOREPINEPHRINE ON UPTAKE AND OXIDATION OF PLASMA FREE FATTY ACIDS IN COLD-ACCLIMATED RATSKiyoshi MORIYA, Hiroshi MAEKUBO, Tsutomu HIROSHIGE1977 Volume 27 Issue 5 Pages 601-616
Published: 1977
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSIn order to know the mode of action of norepinephrine in enhanced utilization of plasma free fatty acids (FFA) in cold acclimation, albumin-bound 14C-palmitate was infused intravenously at a constant rate into cold- and warm-acclimated rats under pentobarbital anesthesia with and without norepinephrine infusion. Rectal temperature, CO2 output and plasma FFA, from which the rates of FFA uptake and oxidation were calculated, were determined simultaneously. Similar fractions, that is, 7 and 5%of the total uptake of plasma FFA by the tissue were immediately oxidized in both cold- and warm-acclimated rats, respectively. Norepinephrine infusion caused a significant increase in all the parameters examined. In addition, during hormone infusion the percentage of FFA uptake oxidized was elevated from 22%in control to 50%in coldacclimated rats. This increment was accompanied with greater increases in rectal temperature and CO2 output. Similarly, in functionally eviscerated cold-acclimated rats, norepinephrine induced a greater increase in the percentage of FFA uptake oxidized than in eviscerated controls. These results indicate that although the FFA uptake was increased simultaneously norepinephrine infusion caused a more marked acceleration of the oxidation of plasma FFA in the cold-acclimated rats than in control rats.View full abstractDownload PDF (1544K) -
Tokuichi HIRAIWA1977 Volume 27 Issue 5 Pages 617-641
Published: 1977
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSThe effects of electrical destruction of the trigeminal motor nucleus of rat masticatory muscles were investigated with the aid of histochemical, cytological and physiological experimental procedures. Atrophy of the muscle fibers occurred 5 to 7 days after denucleation. Changes in the histochemical properties were found after denucleation: oxidative enzyme and glycolytic enzyme decreased, and acid phosphatase increased. Myosin ATPase and acetylcholinesterase activity did not, however, change significantly. Ultrastructural study of the muscle after denucleation revealed the progressive loss of contractile materials and changes of sarcoplasmic substructures. Nerve terminals broke up into small fragments and were replaced by Schwann cells. When electrically stimulated, the muscles exhibited a slower rate of rise of contraction and time delay in reaching peak tension. The stimulus frequency to produce tetanic tension decreased. The cessation of spontaneous miniature end plate pontentials occurred abruptly about 30 hr after denucleation and depolarization of the membrane was observed. Extrajunctional acetylcholine supersensitivity appeared 2-3 days after denucleation and reached a maximum value 10 days after denucleation. Membrane resistance, effective resistance, time constant and length constant increased about five days after denucleation. The rate of rise of the action potential was reduced and the action potential became partially insensitive to tetrodotoxin.
It is concluded that the degenerative effects of denucleation of the masticatory muscle after trigeminal motor nucleus destruction are the same as the effects of cutting the motor nerve. Therefore, in preparation of denervated muscle, the relatively simple procedure of denucleation is recommended in lieu of the more difficult cutting of the nerve fibers.View full abstractDownload PDF (23429K) -
Ichiji TASAKI1977 Volume 27 Issue 5 Pages 643-655
Published: 1977
Released on J-STAGE: June 07, 2011
JOURNAL FREE ACCESSProperties of the excitable sites in the squid axon membrane were studied by using various chemical stimulants and a real-time spectrum analyzer. Intact squid axons immersed in media with a reduced divalent cation concentration develop very small electric responses (1-30μV in amplitude) which repeat at more-or-less regular intervals. The frequency of repetition of these miniature responses falls when the temperature of the axon is lowered. Replacement of a small fraction of the external Na-ion with K-ion is a powerful means of generating miniature responses. Passage of an outwardly directed current through the axonal membrane also evokes miniature responses. This effect of an electric current is attributed to a transport of intracellular K-ion into the axonal membrane. The results of the effects of external application of the salts of Li-, Rb-and Cs-ion indicate that the ability of alkali metal ions to induce miniature response falls in the following order: K, Rb>Cs>Na>Li.View full abstractDownload PDF (1457K)
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