1. The electrical properties of the proximal tubular cells were studied in the newt kidney by using microelectrode techniques.
2. The surface membrane of the tubular cells behaved like a simple resistor when a minute current was applied intracellularly. The changes in the transmembrane potential was linearly proportional to the strength of applied current and there was neither the rectification nor the self-generative response within. a wide range of current strength.
3. The potential change caused by the intracellular application of current spread over considerable distances along the longitudinal axis of the tubule. The tubular wall, thus, behaved like a core conductor.
4. Application of the simple core conductor theory to the model of the tubular wall gave the values of 400μ for the space constant, 3.1×10⁵Ωfor the effective resistance, 836Ωcm² for the specific resistance of the surface membrane and 625Ωcm for the specific resistance of the core (cytoplasm including intercellular membranes).
5. A comparison of the surface membrane resistance to the transtubular resistance suggests that there are significant extracellular shunt paths for electrolytes within the tubular wall. The leaky nature of the proximal segment was ascribed to the presence of such shunt paths.

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Electrical responses of the lateral geniculate body (LGB) to stimulation of the superior colliculus (SC) and the optic chiasm (OC) were examined together with the properties of the optic tract (OT) fibers passing to SC, in unanesthetized cats with immobilization.
The OT fibers passing to SC were grouped into two types, corresponding to t₁ and t₂ of P. O. BISHOP, respectively. The OT antidromic action potential produced by LGB-stimulation was found to interact with that produced by SC-stimulation. This supports the histological finding that the OT fibers passing to LGB send collaterals to Sc.
The mass response of the LGB neurons to SC-stimulation was much the same in configuration and peak time as that to OC-stimulation. With a few exceptions it was found in many LGB neurons that in each unit the response latency to SC-stimulation was about the same as that to OC-stimulation. Since the two stimulating sites are approximately equidistant from LGB, these findings suggest that activation of the LGB neurons by Sc-and OC-stimulation is made through bifurcating OT fibers. It was suggested that there is a projection from SC to LGB. This was evidenced by studying the LGB response to SC-stimulation in cats with eyes chronically enucleated.

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The taste responses of the carp to sucrose, dextrose, levulose, glycine and sodium chloride were analysed by recording integrated electrical responses from the palatine nerve innervating the palatal organ.
The response to sucrose increased asymptotically, rapidly at first and then more slowly, to a saturation level with an increase in concentration of sucrose. The response-concentration curves for levulose and glycine also displayed similar asymptotic shapes, while that for dextrose was sigmoid.
The quantitative effects of stimulating mixtures on the taste response were investigated. A mixture of 0.5M glycine and sucrose of various concentrations produced a response smaller in magnitude than the algebraic sum of the responses to each of two substances, over the concentration range of sucrose from 0.05M to 0.4M. Synergistic effect was observed as the concentration of sucrose increased. Competitive inhibition of receptor response was suggested between dextrose, sucrose and levulose.
The effect of mercuric chloride on the receptor activity was investigated. Application of 10-4M mercuric chloride to the receptor surface for 10 seconds caused an almost complete depression of the responses to dextrose, sucrose and levulose. Response to glycine also was simultaneously but only partially depressed. Response to sodium chloride was usually not affected and even occasionally augmented by the mercury treatment. The effect of mercury on receptor activity appeared occasionally to be reversible, but repeated treatments by mercuric chloride caused irreversible changes.
On the basis of these results problems of the species of receptors (or sites) involved in the processes of stimulation by sugars and glycine are discussed. It was suggested that there may be at least two species of receptors responsive to these substances: one is common to all the substances and the other is responsive to glycine alone.
The authors wish to express their thanks to Dr. J. KONISHI for his encouragement and support during this work, to Dr. H. TATEDA for his valuable criticisms and to Dr. C. J. C. REES for his kindly reading the manuscript. Thanks are also due to Misses P. HIGASHIURA and Y. MORI for their generous assistance in carrying out the experiments and preparing the manuscript.

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Effects of neurohypophysial hormones on the plasma lipid concentrations were studied in the rat.
1. The effect of AVP in decreasing plasma FFA level was less marked than that of LVP. The effect was significantly greater in cold-acclimated rats than in warm-acclimated ones.
2. Plasma concentrations of esterified fatty acids and phospholipids were not affected by single injection of LVP and consecutive administrations of Pitressin tannate for 10 days. Similarly, glycerol concentration in the serum was not decreased after injection of vasopressin and oxytocin. Cholesterol was slightly reduced following successive injections of Pitressin tannate.
3. Ultracentrifugal analysis of rat serum revealed two fractions of lipoproteins: Sf 3-8 and Sf 70-120. The Sf 70-120 fraction increased following vasopressin injection, while it decreased following oxytocin. The concentrations of Sf 3-8 fraction did not change after administration of the hormones.
4. In neurohypophysectomized rats the low-density lipoprotein concentrations were in the normal ranges. The Sf 70-120 fraction disappeared after total hypophysectomy, although Sf 3-8 fraction remained unchanged.

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1) The resting potential of sartorius muscle fibers of the frog was measured at room and cold temperature before and after exposure of the muscle to Li ions. Chemical analyses of muscles, which had been soaked in normal and Li Ringer's solution for varying periods, were carried out for Na, Li and K.
2) Immediately after replacement of normal Ringer's solution by Li Ringer's the muscle fiber showed a hyperpolarization of a few mV, which was followed by a gradual depolarization at room temperature, but at cold temperature the hyperpolarization was maintained for a long time.
3) The initial hyperpolarization is considered to result from the difference of the membrane permeability towards Li ions from Na, P_Li/P_Kbeing smaller (about 0.7) than P_Na/P_KThe delayed and gradual depolarization is attributed to a decrease in the active Na efflux resulting from a decrease in the internal Na concentration and from accumulation of Li inside the cell, which cannot extrude Li ions.
4) On re-immersion of the muscle, which had been soaked in Li Ringer's solution for 2 hr, in normal Ringer's solution at room temperature the muscle fiber was hyperpolarized. This is considered to result mainly from an increase in the active Na efflux, because at low temperature little hyperpolarization was seen.
5) The rates of Li influx and Na efflux, when muscles were immersed in Li Ringer's solution at normal and cold temperature, were calculated from the measurements on the ion content of the muscle. The rates of Li influx and Na efflux were found to be very fast during the initial 30 min after the immersion. They are several times faster than those reported previously.
6) The rates of Li efflux and Na influx were measured, when muscles, previously soaked in Li Ringer's solution for 2 hr, were re-immersed in normal Ringer's solution. The Li efflux rate was also fast during the initial 30 min after the re-immersion. It is smaller than the Na efflux rate, but of the similar order of magnitude. Thus it has been concluded that Li ions can cross the membrane passively at a rate comparable to that for Na.

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The inulin space of the extensor digitorum longus (EDL) and soleus muscle (SOL) of both Wistar-King and Sprague-Dawley rats was determined. The inulin space of EDLs is in general smaller than that of SOLs in both strains. However, a great variation of the space values was observed for both kinds of muscles; the variability of the space was related to a variation in the muscle weight. It has been found that the dimension of the space is linearly related to the reciprocal of the weight in both kinds of muscles and that in the Wistar-King rats the magnitudes of the space (y) in both muscles are expressed by one and the same function, y=659.80/x+2.67, (x, muscle weight).
The dry-to-wet-weight ratio was not significantly different between two kinds of muscles of varying weights in both strains of rats.

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The resting and acting potentials of the extensor digitorum longus (EDL) and soleus (SOL) muscle fibers were measured with a glass-capillary microelectrode, EDL muscle fibers show, on the average, a greater resting potential magnitude and a larger action potential amplitude than those in SOL muscle fibers. The max. rates of rise and of fall is greater in the former than in the latter. The differences in the electrical properties between the EDL and SOL were found to be correlated with a greater [K] i and a smaller [Na] i in the former than in the latter.
Electrical parameters in individual muscle fibers showed an overlap between the EDL and SOL, suggesting that no clear demarcation can be made between the red and white muscle fibers. It is concluded that the red and white muscles are not essentially different from each other and that the difference is only quantitative.

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The membrane constants of the EDL and SOL muscle fibers of the rat were measured by' square pulse analysis'. The transverse resistance of the fiber membrane at 27°C is about 540Ωcm² for both muscles and the membrane capacitance is about 6μF/cm² for the EDL and 4μF/cm² for the SOL. Functional significance of the difference in the membrane capacitance between the two muscles has been discussed.

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Electrophysiological studies with the facial chemoreceptive fibers in the sea catfish (Plotosus anguillaris) showed that the chemoreceptors of the lips display a high sensitivity to dilute solutions of electrolytes having monovalent cations, as found in the palatal chemoreceptors of the carp. No appreciable responses to dilute solutions of electrolytes having polyvalent cations were observed. It was suggested that anion may play an important role in the stimulation of the chemoreceptors. The response magnitude was dependent upon the valency of the anion: the larger the valency, the greater the response. The influences of supporting electrolytes upon the chemoreceptor response were investigated. A strong depressing action of polyvalent cations was demonstrated. Studies on the effects of previous treatments with acid, alkali and dye salts yielded opposite results to those obtained by the carp, suggesting negatively charged reacting surfaces of the chemoreceptor membranes of the sea catfish. An explanation of the possible mechanism of the receptor stimulation is given in terms of an interfacial physicochemical model.

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1. Experiments were performed on 26 adult cats under chloralose anesthesia, in order to investigate whether a relationship exists between the neural mechanisms of the chloralose jerky reaction and the spino-bulbo-spinal (SBS) reflex.
2. A single tactile stimulation to the skin over the body yielded early and late responses from the spinal motor nerves and muscles.
3. The early one, which was apparently due to the segmental spinal mechanisms, was not concerned in the chloralose jerky muscular reaction.
4. The late response may be related to the chloralose jerky muscular reaction. Characteristics of the late response may be summarized as follows: a) On weak stimulation, the late response was recorded mainly from flexor motor nerves. b) The late response was obtained from the spinal ventral roots at different levels along the spinal cord. Its latency became steadily shorter as one recorded from segments closer to the brainstem. c) The conduction velocity of the descending pathway in the late response was about 30m/sec. d) After spinal transection, the late response was completely abolished. e) Pentobarbital sodium anesthesia affected the late response at dosage levels of about 3mg/kg.
5. Above noted observations were almost the same as those of the SBS reflex This suggests that some part of the neural mechanisms of the chloralose jerky muscular reaction may be the same as those of the SBS reflex.

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The induction of epinephrine shock by the intravenous infusion of epinephrine (10μg/kg/min) was characterized by an inability to maintain the initial stationary level of plasma epinephrine, leading to a progressive rise of epinephrine level up to a very high values (300-400μg/l) within a few hours. When epinephrine was infused intra-portally at the same rate, the arterial plasma ne attained a far lower initial level and neither a secondary rise nor urred during the infusion period of 4 hours. Thus the secondary lasma epinephrine level indicating the limit of epinephrine removal te of the intravenous infusion was found to be due to circumstances inish participation of the potential ability of the liver in removing le. The well documented reduction of splanchnic blood flow with a ogic dose of epinephrine has been suggested as the cause. The rise in plasma epinephrine level and the attendant shock were not with intravenous infusion at rates less than 5μg/kg/min during a usion period.
Administration of glucocorticoid markedly potentiated the epinephrine removing capacity of the liver, while adrenalectomy reduced it. This might provide a satisfactory basis for the interpretation of the protective effect of glucocorticoid against epinephrine shock.

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