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雑誌目次

雑誌文献

生体の科学13巻2号

1962年04月発行

雑誌目次

Symposium on Permeability of Biological Membranes

In Opening the Symposium

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ページ範囲:P.53 - P.53

 It is our great pleasure to open the second international symposium on the permeability of biological membrane with the attendance of Dr. A. K. Solomon from Harvard Medical School.This symposium also corresponds to the second conference of the Research Committee on Biological Absorption and Secretion.The first international symposium was held on the occasion of visit of Travelling Mission of International Union of Physiological Sciences to Kyoto(Director:Dr. M. Visscher)on May 30th, 1960.The committee on Electrolyte Transport through the Biological Membrane, took the initiative in opening the 1st symposium.

The Mechanism of Transport of Inorganic Anions across the Intestinal Wall of the Rat

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ページ範囲:P.54 - P.56

 1)In the isolated small intestine of the rat the efflux of inorganic phosphate and iodide ion from the serosal to the mucosal side decreased when modified Ringer was applied to the mucosal side and the potential difference across the intestinal wall attained a new value, the mucosal side becoming positive.This decrease could not be influenced even when the P. D. was restored to the normal value by externally applied current.But it could be partially recovered by raising the hydrogen ion concentration on both sides.
 2)When similar P. D. was developed by externally applied current with normal Ringer on both sides, the efflux of phosphate and iodide changed in accordance with the notion of simple free diffusion.
 3)Using neutral collodion membrane of porous character as a model, the viscosity of the solution was shown not to play a dominant role in determining the rate of transport of phosphate and iodide.

A Study of Absorption Mechanism of Amino Acids through Intestinal Wall

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ページ範囲:P.57 - P.62

 1.In vitamin B6 deficiency induced by L-penicillamine in vivo, the rate of absorption of L-amino acids is decreased but can be restored to the normal rate by the addition of vitamin B6.The rate of absorption of D-isomer is far less than that of L-isomer and cannot be accelerated by the presence of vitamine B6
 2.Using the in vivo method, it was demonstrated that L-amino acids were actively transported from mucosal side of intestine, and evidence was presented that pyridoxal phosphate may play an important role in its active transport.
 3.With C14-glucose or C14-alanine, the rate of contribution of endogenous pyruvate to the transfered alanine was determined and it was found that over twenty percent of the transported alanine was derived from endogenous pyruvate, while in the presence of glutamate the amount originated from endogenous pyruvate increased up to over sixty percent.
 4.The in vitro experiments with heavy water, revealed that α and β hydrogens of the alanine transported was found to be replaced by deuterium, in spite of that the contribution of endogenous pyruvate was minimized within ten percent by avoiding the addition of glucose in the medium.
 5.From the above findings, it was assumed that the alanine transported was subjected to form Sciffbase with pyridoxal phosphate, through double transamination or some other reactions associated with this coenzyme.

Amino-Acid Transport across the Brain Cell Membrane

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ページ範囲:P.63 - P.68

 When γ-aminobutyric acid was accumulated actively into guinea pig brain cortex slices, P32 turnover of phospholipid fractions,particularly phosphatidic acid fraction in cytoplasmic particulates of the brain slices which was separated by slicic acid column-chromatography was strongly accelerated.And these phenomena were found only with the brain slices, but not on kidney or liver slices.
 The experiments of competitive inhibition for active transport were performed between two kinds of amino-acids.When γ-aminobutyric acid and glutamate, or γ-aminobutyric acid and aspartate, were added simultaneously in the same concentration, these amino-acids were accumulated into brain slices independently without any hindrance.But if γ-aminobutyric acid and β-alanine or glutamate and aspartate were added to the medium at the same time, the accumulation of these amino-acids into brain slices was suppressed considerably.
 The accumulation of γ-aminobutyric acid and glutamate derivertives in brain slices was examined, and an importance of molecular structure of the amino-acid for active transport across the brain cell membrane was discussed.

Inactivation Process of K-Permeability in Skeletal Muscle Fibres

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ページ範囲:P.69 - P.72

 In 1941 Cole and Curtis3) observed in the squid giant axon that depolarization caused a striking decrease in the membrane resistance. Later this phenomenon was confirmed by Hodgkin, Huxley and Katz9)(1949),and was designated as "delayed rectification." They attributed this decrease in the membrane resistance to an increase in potassium permeability which occurred as the membrane was depolarized. They interpreted part of the cause of repolarization phase of action potential in the squid giant axon by this increase in K permeability.

The Effect of Deoxycorticosterone-glucoside on the Sodium Transport in Frog Skin

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ページ範囲:P.73 - P.77

 1)The effect of mineralocorticoids on the active sodium transport was studied through the short-circuited isolated frog skin, according to Ussing's method.The short-circuitcurrent was electrically measured and simultaneously the sodium flux was determined,using 22Na as tracer.
 2)Deoxycorticosterone-glucoside(DCG)increases the active transport potential, ENa,suggesting the direct action of mineralocorticoid on Na-pump.
 3)When applied to the medium bathing the corium surface at the concentration ranging from 1 to 10μg/ml, DCG definitely enhances the short-circuit current, which is believed equivalent to the actively transported sodium netflux.
 4)DCG, which is added into the inside(corium side)solution, stimulates the current more effectively than when added to the outside(epidermal side)solution.Accordingly it is supposed that either there may exist some diffusion barrier in ep dermis which inhibits the passage of DCG into the skin, or Na-pump may be located near corium in frog skin.
 5)DCG increases the sodium influx and decreases outflux and thus an increased netflux appears.This apparently paradoxical dual action of DCG upon the sodium influx and outflux through frog skin, can readily be explained mathematically as the result of increased netflux across the skin.
 6)The action of progtsterone was not unequivocally demonstrated, while corticosterone and hydrocortisone invariably increased the short-circuit current though not so strongly as DCG does in the same concentration.

Uncoupling of Na Secretion from K Uptake by DNP in the Sartorius Muscle of Toads

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ページ範囲:P.78 - P.82

 1.Sodium and potassium content of the sartorius muscle of toads was measured after subjecting it to the influence of monoiodoacetic acid or DNP.
 2.The muscle poisoned with monoiodoacetic acid shows accumulation of sodium and loss of potassium, both sodium gain and potassium loss being equal.
 3.DNP, when its concentration is low or when the temperature is low, first facilitates sodium extrusion, and, with a sufficient concentration and temperature of 25℃,it inhibits sodium extrusion, although the inhibition of sodium extrusion is much less than that of potassium uptake.
 4.In DNP-poisoned muscle the oxygen uptake, measured at 25℃,is increased without accompanying an increase in sodium extrusion.

Importance of Ca Ions on the Excitable Membrane

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ページ範囲:P.83 - P.90

 Recently it was found that the Ranvier node of toad's nerves can generate action potentials in sodium free isotonic solution of choline chloride, CaCl2,KNO3 or even in sucrose solution, when an adequate intensity of hyperpolarizing current is applied to the nodal membrane1).Similar observations to those of the Ranvier node were made in the present investigation on the giant neurons in the supraoesophageal ganglion of a marine pulmonate mollusc, Onchidium verruculatum.

Glucose Absorption and Para-Aminohippurate(PAH)Excretion by the Proximal Convoluted Tubule Cells in Rabbit Kidney

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ページ範囲:P.91 - P.95

 The active transport mechanism of para-aminohippurate and glucose in the proximal tubule cells of rabbit kidney was studied by electron microscope with special reference to functional activities, and mechanism of active transport was discussed morphologically.It was suggested that the architecture of the proximal tubule cells is very suitable for the two-way-directed transport process.

Mechanism of Water Secretion Through Salivary Gland

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ページ範囲:P.96 - P.99

 Recently, Dr. F. Yoshimura1) pointed out,from his electronmicroscopic study, that the myoepithelial cell of submaxillary gland of dogs presented a picture which indicates that it contracts in order to squeeze the acinal cell of the gland after the pilocarpine stimulation(0.5mg/kg).

Use of Isotopes in Ion Transport Studies

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ページ範囲:P.100 - P.106

 In discussing the broad topic of "The Use of Isotopes in Ion Transport Studies," it has seemed best to confine myself to an account of one particular scientific investigation which has relied heavily and continuously on the use of isotopes. This investigation, which is concerned with the basic mechanism governing the absorption of water by the proximal tubule of the kidney, was initiated in our loboratory in 1953 and has occupied our attention continuously since that time.

基本情報

生体の科学

出版社:株式会社医学書院

電子版ISSN 1883-5503

印刷版ISSN 0370-9531

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