In a closed lung-box system an equilibration process of unevenly evenly distributed pressure was studied. According to the theoretical analysis of the pressure-time curve, a method of obtaining the resistance and compliance of the lungs and thorax simultaneously from the recorded pressure curve was developed. A 100-liter airtight box was used as a capacity box and the pressure in this box was measured during a passive inhalation process, where the box pressure was increased initially to 10-30 cmH₂O. The pressure curve obeyed a simple exponential function tion of inhalation time; thus, the compliance and resistance were estimated mated from its time constant and initial box pressure values. The compliance was also calculated from the pressure observed at equilibrium. The compliances obtained at the initial transient and final equilibrium stages were referred to as the dynamic (C_d) and static (C_s) compliances, respectively. Measurements were achieved on eight normal subjects. Although the C_d values showed a large dispersion, the mean value obtained tained in a given subject agreed well with the C_s values. On the other hand, the C_s values showed a good reproducibility. Mean values for C_s and C_d were about 0.1 liter/cmH₂O. The resistance evaluated by dividing the time constant by the compliance of the lung-box system was nearly identical with that measured by the forced oscillation method. The average value was 2.4 cmH₂O/liter/sec.

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1) The effects of tetrodotoxin (TTX), procaine and acetylcholine choline (ACh) were investigated both the recording the receptor potential in gustatory cells by measuring and the integrated response of their afferent nerves in rats and frogs.
3) TTX (10^-6 g/ml) did not induce electrical responses in the gustatory cells of frog and rat or in chorda tympani nerve of rat and glossopharyngeal nerve of frog, nor did it suppress the generation of the receptor potential in response to gustatory stimuli. Procaine (0.1 or 0.5 %) also had no effect on the receptive process in the rat. However, in the frog the magnitude of the integrated response of the nerve in response to NaCl and CaCl₂ was depressed after the tongue had been soaked in TTX.
3) ACh (10^-4 g/ml) did not elicit electrical response in the gustatory cell and the nerve of the rat. In the frog, 10^-3 g/ml ACh did not produce any immediate response in gustatory cell but the magnitude of integrated response of the nerve to NaCl was modified after the tongue had been soaked in ACh for some time.
4) It was suggested that the penetration of solutions from the tongue surface might hardly occur into the space surrounding the gustatory cell bodies of the rat, while in the frog occur in some extent.

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We reported in the previous paper (FUJINO et al., 1961) the phenomenon that, after the completion of immersion in a hypertonic glycerol-Ringer, fibers of frog skeletal muscle give a selective inhibition of contraction in the presence of action potential. In the present paper, the original results on this description are presented, and several observations on the mechanism of the phenomenon are also given:(1) A quite similar phenomenon occurs when urea is substituted for glycerol, indicating that the phenomenon can be produced regardless of the kind of non-electrolyte used;(2) an inhibition of contraction due to the addition of glycerol followed by its removal is observable in crab leg muscle fiber and in frog stomach, where it occurs relatively obscurely, but it is not found in heart ventricle of frog. From the present results and other experimental observations by us, it is deduced that the phenomenon can occur widely in various kinds of muscle cell regardless of whether the transverse tubule system exists or not, two factors are considered to be essential for the appearance of the phenomenon:(1) penetrability of the substance or non-electrolyte used through ‘membrane’ system, which might be in contact with extracellular fluid and (2) osmotic pressure.

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The anterior pituitary functions of synthesizing and releasing growth hormone (GH) and prolactin were determined in vitro after exposing the rat to mild (6°C) or severe cold (1°C) for periods ranging from 4 hr to 7 days.
1) Mild or severe cold exposure for 12 hr depressed the GH synthesis function. Severe cold exposure for 12 hr stimulated the GH release function.
2) Mild cold exposure stimulated the prolactin synthesis function within 4 hr and severe cold exposure within 2 hr. Severe cold exposure for 12 hr stimulated the prolactin release function.
3) The effects of chronic cold exposure for 7 days were substantially the same as mentioned above.
4) Pituitary whole protein synthesis was depressed by mild or severe cold exposure within 12 hr, and the effects lasted for a 7-day exposure period. Whole protein hormone release did not change significantly.
5) The serum level of free fatty acids (FFA) was elevated by severe cold exposure within 4 hr and returned to the normal level by 7 days. Serum glucose and protein did not change throughout the cold exposure period.
The observed facts suggested that the cold stimulus acts directly on the hypothalamus through neural pathways and that the altered pituitary functions of synthesizing and releasing GH and prolactin play a role in metabolic readjustment to a cold environment.

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The effect of ovarian steroids on the maintenance of pregnancy in rats on an isoleucine-free diet was investigated. A combination of 0.5 μg of estrone and 4 mg of progesterone or one of these steroids only was injected into the rats for various periods until mid pregnancy. Administration of estrone with progesterone from day 3 to 13 prevented fetal loss completely, and even when injected only from day 9 to 13 about 80 % of the rats maintained pregnancy. Pregnant rats fed an inadequate diet without steroids failed to maintain pregnancy. Pregnant rats receiving deficient diets with or without steroids were sacrificed at intervals during early and mid pregnancy and the nucleic acid and protein contents of the uterus and incorporation of ¹⁴C-leucine into uterine proteins were examined. On day 7 of pregnancy, growth of conception products, total RNA, DNA, and protein in the uterus were significantly less in rats that did not receive steroids than in those that did. Incorporation of ¹⁴C-leucine into uterine proteins was the same in both groups until day 11, but on day 14 the incorporation rate rose in the group in which pregnancy was maintained and fell in the group in which it failed. These results suggest that ovarian steroids, particularly progesterone, may act on the uterus to inhibit protein degradation, at least during mid pregnancy. The total amount of estrogen receptor proteins in the uterus was maintained until quite a late stage of pregnancy in rats on an inadequate diet.

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In an attempt to clarify why the seasonal variation of basal metabolic rate (BMR) of Japanese is different from that of Caucasians (white American and Canadian), animal experiments were performed to clarify the effect of dietary composition on thyroid activity, metabolic adaptation to heat, and tolerance to cold, using groups of rats fed on different kinds of diets. Results obtained are as follows:
1) By radioisotope techniques with ^13II, it was demonstrated that the ¹³¹I uptake of thyroid gland is higher and PB¹³¹I is higher in the high-fat diet groups than in the control diet rats, while the conversion ratio and the fractional turnover rate of thyroxine are not significantly different between the two groups. Thus it is inferred that the thyroid activity is promoted by feeding rats a high-fat diet.
2) The resting oxygen consumption of rats which were reared in the control temperature.(20°C) as well as kept at 30°C for 5 weeks was higher in the high-fat diet group than in the high-carbohydrate group. The resting metabolism was reduced by heat acclimation. The reduction rate of 0₂ consumption in heat acclimation was less in the high-fat diet group than in the high-carbohydrate group.
3) Assuming that an adaptative process of the thyroid gland may be involved in the mechanism of metabolic adaptation to heat and cold and that the experimental results of metabolism in rat may be applicable to the mechanism of metabolism in man, the following explanation was presented for the difference of seasonal variations of BMR between Caucasian (white American and Canadian) and Japanese. Japanese present a seasonal variation of BMR, increasing in winter and decreasing in summer, as an outcome of metabolic adaptation to heat and cold in various seasons. In Caucasians, however, their thyroid activity is promoted by the intake of a high-fat diet. This promotion of thyroid activity may inhibit the reduction of metabolism in heat acclimatization, thus maintaining the BMR at a constant level throughout the year. Thus the appearance of climatic effect in the BMR of Japanese may be due to their habitual high-carbohydrate diet.
4) In acute exposure to air of 10°C, the high-fat diet group showed superiority in maintenance of body temperature in the cold, while the high-carbohydrate group showed a most remarkable drop of rectal temperature.

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Reflex discharges in the vagal nerve fibers elicited by tactile stimulation of the facial distribution area of the trigeminal nerve have been investigated in the urethane-chloralose anesthetized cat.
A brief light mechanical stimulation applied to an appropriate area on the dorsum of nose or to the inner surface of nasal cavity elicited reflex discharges in the superior and inferior laryngeal nerves on both sides, but not in the thoracic vagus. A similar stimulation applied to the area surrounding the nostril sometimes also elicited the reflex discharges.
The reflex discharges elicited by stimulation of the nasal skin have been attributed to a transmission of cutaneous distortion to subjacent deeper nasal structures. Therefore, the reflex has been designated as the nasolaryngeal reflex.
Electromyographic studies revealed that in the nasolaryngeal reflex motor units of adductor muscles (the cricothyroid, thyreoarytenoid and lateral cricoarytenoid) discharged single spikes following a brief light mechanical stimulation of the nose. A resultant flick closure movement of the vocal cords was observed. Concomitantly, the antagonist muscle, the posterior cricoarytenoid, showed a suppression of spontaneously appearing inspiratory discharges.

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The nature of masticatory movement and related muscle spindle afferent activity was studied on awake monkeys. The pressure acting on the molar surface of the tooth and masseter EMG may develop in two phases, i. e. an early jaw movement and a late biting. Out of 20 identified spindle afferents, 10 units in ten monkeys showed a rate increase during jaw-muscle closing and the remaining 10 units showed a decrease of the rate. Although there were two phases to the masseter contraction, no correlation was found between the two phases and the spindle afferent discharge pattern. It was concluded that during voluntary jaw closing the fusimotor activation occurred simultaneously with masseter muscle activation.

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Oxygen dissociation curves of human adult and cord blood were constructed over a wide range of pH values (5.9-8.7). The cord blood was characterized by a high oxygen affinity as compared with adult blood in the pH region above 6.3. Below that pH region the relationship was reversed.
The intracellular pH and 2, 3-diphosphoglycerate (DPG) content of red cells of these two kinds of blood were little different. Upon their incubation at 38°C, both kinds of blood showed an increase in oxygen affinity concomitant with a decrease in the DPG content. From these experiments with the two sorts of blood incubated for various lengths of time it was concluded that the higher oxygen affinity of fetal blood was due mostly to the predominant presence of hemoglobin F, which is not different in oxygen affinity from hemoglobin A but which is quite different in susceptibility to the inhibitory effect of DPG upon oxygen affinity.

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