Capsaicin has been known to produce a hypothermia in the adult animal, probably by its action on the warm-detectors responsible for thermoregulation. The effect of capsaicin on the body temperature was studied in the new-born rats aged 6 hours to 5 days old. Under ether anesthesia, a stainless-steel guide cannula (0.5mm, o.d.) was subacutely implanted into the brain, aimed more or less at the preoptic area and anterior hypothalamus (PO/AH) . The animals were held in a prone position on a sponge rubber mat in a‘neutral’ enviroment where the animal could maintain the rectal temperature (T_re) at 36-37°C. The subcutaneous injection of capsaicin (5-10μg) produced a sudden fall in T_re (1-2°C) . With repeated injections of increasing doses, the hypothermia diminished progressively and finally the animal became completely unresponsive to a large amount (1mg) of the drug (desensitization) . Direct injection of capsaicin (5μg) into PO/AH also produced a prompt fall in T_re even in 1 dayold rats and the repeated injection resulted in the diminished responses. The injection outside PO/AH or the injection of solvent alone had no effect. Since the PO/AH warm-sensitive neurons in the new-born rat specifically respond to capsaicin, it is suggested that the capsaicin-induced hypothermia is brought about, at least in part, by its action on the PO/AH warm-sensitive neurons. These results indicate that the neonatal PO/AH warm-sensitive neurons attain some degree of maturity to respond to capsaicin, to lower the body temperature and to be desensitized by capsaicin.

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How does the LPS-pyrogen act on the nervous system was analyzed by the Limulus test (pyrogen test) for endotoxin in blood plasma. A cell lysate prepared from amoebocytes of Limulus polyphemus is an extremely sensitive indicator for the presence of endotoxin (LPS-pyrogen) . The state or grade of gelation reaction characteristic of a quantity of endotoxin in plasma is dependent on the concentration of clottable protein in the amoebocyte lysate and endotoxin in the assay mixture. In intact rabbits, gelation reaction for endotoxin in blood plasma during fever induced by LPS-pyrogen injected intravenously was gradually diminished in the time course, though higher temperature in rectum was still kept. And the simultaneous detection of endotoxin in the liquor in central nervous system, the result of the gelation reaction was almost negative. On the contrary, gelation reaction tested in liquor during high fever induced by the lateral ventricular as well as by the subdural administration of LPS-pyrogen was strong positive, but was almost negative in blood plasma. These results suggest that LPS-pyrogen has a strong effect directly on the central thermoregulatory mechanism if it is administered in central nervous system, but LPS-pyrogen itself does not pass through the blood brain barrier. The first and the second peak of the biphasic response to intravenous or intraventricular administration of LPS-pyrogen might be mediated by both exogenous and endogenous pyrogen which were discussed from the results in the present investigation.

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血圧受容器反射と化学受容器反射の中枢性相互関連については多くの報告がある。しかし, 温度刺激に対する地域性血管反応およびその基礎をなす地域性交感神経系反応が詳しく検討されているにもかかわらず, 血圧受容器調節と体温調節の中枢性相互関連についての報告は少ない。今回の実験シリーズは, 循環と体温の調節機構の中枢性相互関連を明らかにすることを目的として行った。
方法: 無麻酔ウサギの腎交感神経活動性 (RSらNA) は, あらかじめ埋め込んだ電極を用いて記録した。直接記録のほかに, 2秒毎に積分した値を記録して, RSNAの指標として用いた。あらかじめ埋めこんだ大動脈または下大静脈バルーンを用いて平均動脈圧 (MBP) を安静時MBPより, 5, 10, 20mmHg上昇または下降させた。直腸温, 耳朶温を同時に記録した。
常温環境 (25℃) , 冷環境 (15℃) , 温環境 (35℃) でRSNA血圧応答曲線を, MBP変化時のRSNAの応答より作製した。冷環境では耳皮膚血管は収縮しているがふるえのない状態, 温環境では, 耳皮膚血管は拡張しているが著明な呼吸数増加 (熱あえぎ) のない状態で実験した。異った環境でのRSNA血圧応答曲線の比較には, 応答曲線の助変数, RNSA Range, median BP, reflex gainを計算して, 各環境間について有意差を検定した。
結果と考案: 物理的体温調節の血管性調節域の範囲内, すなわちふるえや熱あえぎのない域内では, 温環境の安静時MBPは, 冷環境におけるより低いが, 安静時MBPにおけるRSNAには有意差を認めなかった。RSNA血圧応答曲線の3つの助変数は, すべて温環境の方が, 冷環境より有意に低い。このことから, RNSAの応答に対して, 血圧変化に関する入力と, 温度に関する入力との間に中枢性相互関連が存在するものと推定される。この中枢性相互関連では, 冷入力は促進的に, 温入力は抑制的に働く。
高温環境において熱あえぎがある場合にも, RSNAに対して, 両入力の間の中枢性相互関連が存在する。しかしその方向は, 熱あえぎのない温環境とは逆となる。このことは, 高温環境において応答曲線の3つの助変数すべてが, 冷環境より増加することから推定される。

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温熱性発汗の発現時点の部位差に体位が関与するとの想定のもとに, 主として立位, 椅座位, 仰臥位について, ヨード・でん粉紙法と連続発汗記録法を用いて4～8部位の発汗の発現過程を調べた。暑熱負荷には室温38℃, 気湿40%の人工気候室に被検者を入れる方法と26℃から0.2℃/minの速度で室温を上げて行く方法をとった。
立位・椅座位では各部位の発汗はほぼ同時か, せいぜい数分以内に相前後して発現することが多かったのに対し, 仰臥位では上半身の発汗発現がいちじるしく遅延した。さらに側臥位では下になった側の半身の発汗発現が大幅におくれ, また両側側胸部を圧迫した状態では上半身, 片側側胸部の圧迫では同側の上半身の発汗発現が遅延した。これらの結果より, 発汗発現の部位差には体位が決定的な影響を及ぼし, これは圧一発汗反射にもとつくものであると結論される。また, 圧迫部位の高さにより, 反射的に発汗発現抑制の起こる区域に多少のずれが認められ, この反射が脊髄レベルを介して起こることを示唆する。
暑熱環境下の皮膚温は部位によって大差なく, これが発汗発現の部位差に有意な影響を与えることは考えられないが, 部分温浴で局所皮膚温を大きく変化させると発汗発現時点にかなりの変動をもたらした。
発汗能が低い部位ではそれが高い部位より発汗発現が多少おくれる傾向があるが, 顕著ではなかった。

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A model with regard to wet heat loss from skin surface was made taken the effect of humidity on thermal sensation into consideration. The present model is consisted of two control regions an—environmental region where the rate of moisture exceeds the maximum environmental capacity to accept evaporated moisture and an environmental region where the rate of moisture is less than the environmental capacity. We call the former region I and the latter region II.
In region I, by applying and developing wettedness model by Gagge et al with regard to skin evaporation, the evaporative heat loss in this region is given by the following equation.
H_e=κh_c (Ψ_sX_ss-X_a) W
where, H_e: wet heat loss from skin surface
κ: modified Lewis relation
h_c: convective heat transfer coefficient for the human body
Ψ_s: percentage humidity at skin surface
X_ss: saturated humidity ratio at skin temperature
X_a: humidity ratio in ambient air
W: wettedness by Gagge et al
Although percentage humidity Ψ_sfor the boundary layer at skin surface is always unity in wettedness model, that in the present model is assumed to be not always unity and to have close relationship to environment humidity. As a consequence of surveying from clothing worn, air movement and so forth, we obtained a relation between percentage humidity at skin surface and that in ambient air.
In region II, man's ability to squeeze out the moisture is assumed to have a certain limit. A moisture control center regulates the quantity of moisture and wet heat loss is given by the following equation.
H_e=G⋅L
where, G: quantity of moisture (insensible perspiration and sweat secretion, at comfort condition, only insensible perspiration)
L: latent heat
Heat balance between man and his environment is expressed by considering four main heat loss terms in a steady state—radiation, convection, evaporation and respiration. Based on the rational heat balance equation derived, a comfort chart was proposed as an index of comfortable sensation and for enviromental assessment and the proposed comfort line was compared with experimental data and theoretically derived comfort lines by earlier workers.

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自転車エルゴメーターによる運動時 (24.5W～98.0W) の体温を, 発汗のおこらない条件下で測定した。
1.環境温26℃, 10分間の運動時に, 手掌, 前腕, 胸の皮膚温は運動強度 (49.0～98.0W) に比例して低下した。熱産生量が大となるにつれて, 皮膚温低下域は末梢から体幹へ拡大した。
2.環境温10℃, 1時間の運動時では, 直腸温は運動強度 (49.0～98.0W) に比例した上昇を示したが, 平均皮膚温は安静時とほぼ同じである。運動終了後皮膚温は一過性に上昇した。
これらの知見は運動時の熱産生量の増加にともなっておこる体温調節性の皮膚血管拡張が, 非温熱性要因による血管収縮によって相殺される可能性を示唆する。

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本土生育者の男子大学生 (M群) , 沖繩生育者の本土移住期間が2～3年の男子大学生 (O_I群) および沖繩生育者の夏季の沖繩への帰省直後 (O_II群) の寒冷血管反応および寒冷曝露時の生理的反応を測定して次のような結果を得た。
1) O_I群の寒冷血管反応はM群と比較して反応発現に時間が有意に長く, 反応発現温度および平均皮膚温がやや高かった。O_II群の反応は他の群と比べて反応発現時間が著しく遅延し, 反応発現温度および平均皮膚温が高かった。即ち沖繩生育者の反応の特徴は寒冷血管反応の発現が遅いことにある。抗凍傷指数はM群, O_I群, O_II群の順に小さくなっており, 沖繩生育者は本土生育者より指の耐寒性が劣っていることおよび沖繩の亜熱帯季候は指数を減少させることが判った。
2) 寒冷曝露時の平均皮膚温の下降度はO_II群が最も小さく, M群が最も大きかった。平均皮膚温の絶対値はM群が最も低く, O_II群が最も高く, 寒冷環境下の放熱量の増加を防ぐ能力はO_II群が最も劣り, M群が最も秀れていた。
3) 安静時代謝量はM群がO_I群, O_II群より大きく, 寒冷曝露後30分値ではO_II群の代謝量の増加はM群, O_I群より有意に大きく, 60分値ではM群の代謝量の増加は, O_I, O_II群より可なり小さかった。O_II群では30分値の代謝量の増加は30分値のそれより大きくふるえが発現しやすい。沖繩生育者の本土移住者の耐寒性は本土生育者のそれよりわずかに劣っているが, 沖繩に帰省するときは著しく耐寒性の低下がみられる。

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Interested in the influences of wind on human body under exercise, the present authors had prepared a handmade wind tunnel with air conditionning and studied some physiological reactions under wind.
Five healthy male subjects (aged 22-24 yrs.) were loaded with a bicycle ergometer work at the rate of 600 kpm/min for 30 minutes, under three different wind velocities (no wind: W₀, 3.8m/sec: W₁ and 5.7 m/sec: W₂), with an air conditionning of temperature: 24°C, relative humidity: 60%.
Following results were obtained:
1) Heart rate decreased by wind (at W₀: 128, W₁: 121 and W₂: 120 beats/min) ; but oxygen intake remained constant (1.5-1.6l/min) .
2) Mean skin temperature kept a certain level rather lower under wind and the change of rectal temperature was not observed.
3) Total sweat rate and local sweat rate showed a decrease by wind, but Na and Cl concentrations in sweat did not change, though there were individual differences.
4) Heat Tolerance Index (HTI) decreased under wind.
5) Under wind, the heat loss by evaporation and convection decreased double and that by radiation decreased to about 1/3 compared with the no wind conditions.

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Electrocardiographic changes in thirty men of 16th Japanese Antarctic Expedition (JARE-16) were studied during the wintering at Syowa Station from February 1975 to January 1976. They were men in good health with average age of 31.0 and a range of 24 to 45. Electrocardiograms were recorded before, after and one year at Syowa Station (February, May and July 1975) . Heart rates, QRS voltage of the precordial leads (SV1+RV5) and electrical axis of the QRS were analysed. Body weights, skinfold thicknesses and blood pressures were measured and hematological examinateions were performed.
Long term changes in physical work capacity in 21 men of 17th JARE were studied during the wintering from February 1976 to January 1977. All were in good health with an average age of 32 years and a range of 24 to 54. Physical examinations and physical performance tests were done in March, June, September and December 1976.
1) Sinus bradycardia was observed in two subjects and first degree A-V block in one subject before, during and after the wintering. Supraventricular and ventricular premature contractions were detected respectively in one subject only in May 1975. Premature contractions might be induced by excessive taking of coffee, alcohol and tobacco during all-night vigil. ECG's recorded in February and July 1975 did not show significant changes in QRS axis, but the heart rates were decreased from 70 to 65.5 (beats/min.) and the QRS voltage (SV₁+RV₅) from 29.7 to 26.8 (mm) . There were no correlations between the decrease in heart rates or QRS voltage (SV₁+RV₅) and the changes of body weights, blood pressures, skinfold thicknesses and hematological data.
2) Pulmonary function (forced vital capacity), body weights and high jump tests were not significantly altered throughout the year. Harvard score, dynamic muscle endurance, grasping power and agility test score increased significantly in September and December. Skinfold thicknesses increased from March to September but decreased in December. Heart rates after Harvard step tests dereased in September and in December. Physical work loads were mild in the winter and heavy in the summer.
These data may be explained on the basis that immobility in the winter season during the wintering might cause deterioration of physical work capacity and induce the electro-cardiographic changes.

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The effects of bioisolation on leucocyte counts, serum immunoglobulin concentrations and normal microbial flora were studied at two Japanese Antarctic Survey bases, Syowa Station and Mizuho Camp, during 17th Japanese Antarctic Research Expedition from 1975 to 1977.
Thirteen wintering members were divided into two groups; one was composed of six men who wintered at Syowa Station (Syowa group) and the other was composed of seven men at Mizuho Camp (Mizuho group) . The following results were obtained;
1. Microbiological observation revealed the facts that the drinking water of Syowa Station was highly polluted but that of Mizuho Camp was relatively sterile.
2. In Syowa group, total aerobic microorganisms, especially bacillus spp., in feces were increased significantly in number during early period of wintering, while in Mizuho group, those were decreased significantly after wintering. Pharyngeal microbial flora did not change significantly.
3. In Syowa group, leucocyte counts and serum immunoglobulin concentrations of Ig G and Ig A were increased significantly during early period of wintering. In Mizuho group, leucocyte counts did not change significantly, but Ig G waa decreased significantly after wintering.
Above results suggest that 1) the changes of microbiological environment alter the composition of normal human microbial flora, 2) those altered microbial flora, especially aerobic microorganisms, can change the host's immunological status, and 3) the changes of leucocyte counts and immunoglobulin concentrations may be resulted from altered intestinal microbial flora.

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Circadian rhythms of locomotor activity and plasma corticosterone were determined simultaneously in individual rats which were injected intracerebroventricularly with 6-hydroxy-dopamine (6-OHDA), a specific depletor of catecholamines. Under light-dark cycles (LD), 6-OHDA treated rats showed essentially normal circadian rhythms of both functions. Under 200 1ux continunous light (LL) the locomotor activity in the drug-treated rats ran freely with a period slightly longer than 24.0 hr, free-running parameters such as level, amplitude and period of the locomotor activity being the same with those of control rats. The circadian rhythm of plasma corticosterone in control rats also ran freely under LL, resulting in a reversal of their phase after 12 days exposure to LL. However, the rhythm disappeared in 6-OHDA treated rats under LL. These results suggest that the brain catecholaminergic components are indispensable for the circadian rhythm of plasma corticosterone to freerun normally under LL, but are dispensable under LD. A pausible model consisting of two oscillators is proposed to explain these findings.

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Previously I reported that Congo red clearance from the blood of rats was faster in the dark period than in the light, and further, it was faster in the younger animals than the older. In the present study using Salmonella enteritidis instead of Congo red, the relationship was completely reversed; the clearance from the blood was faster in the light period and in the older age group than in the dark and in the younger group.
The difference of the clearance rate between Congo red and S. enteritidis is supposed to be due to the different physicochemical nature of surface of particles of chemical substance and living organism.

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The effect of constant illumination (LL) on circadian sleep rhythm and sexual cycle were studied in female albino rats (Sprague-Dawley, SD), hooded rats (Long-Evans, LE) and SD rats born and reared in LL. Cortical EEGs and dorsal neck EMG were used to monitor slow wave sleep (SWS), paradoxical sleep (PS) and alertness. The sums of the duration of each SWS and PS were expressed for each two hours. The bihourly distributions of SWS and PS in each animal were illustrated as graphs of circadian sleep rhythm. All experiments were performed under constant temperature (24±0.5°C) and humidity (45-55%) .
1. The strain differences between LE and SD were observed in circadian sleep rhythm under control lighting schedule (LD) . The circadian sleep rhythm in SD rats showed the sexual differentiation and the changes during sexual cycle. While in LE rats, any differences of sleep rhythm were not observed between both sexes or during sexual cycle.
2. The long term LL exposure (40-50 days) of SD rats caused the persistent estrus (PE), disrupted the circadian sleep rhythm and resulted the ultradian sleep rhythm of 4-6 hours periods. After the long term LL exposure of more than 6 months, SD rats returned to LD schedule. One month after returning to LD schedule, 3 out of 8 rats recovered the regular sexual cycle and showed the regular circadian sleep rhythm similar to control. While, the other rats showed PE or irregular sexual cycle and indicated the regular SWS rhythm, but the phase of PS rhythm in these rats was dissociated from that of SWS rhythm. On the other hand, LL exposure of LE rats also caused PE, but delayed more 30 days than SD rats. Furthermore, the electrodes implantation for these PE-LE rats recovered the sexual cycle and maintained over 50 days. The sleep rhythm in LL exposed LE rats indicated ultradian rhythm, but still maintained the circadian freerunning rhythm.
3. In the SD rats born and reared in LL, the completion of PE delayed more 20 days than control rats. The sleep rhythm in these rats showed the circadian freerunning rhythm and the changes during sexual cycle.
From these results, it is suggested that LE rats are less effective to LL exposure than SD rats and SD rats born and reared in LL may have the inheritable circadian freerunning hrythm. But, it is the future problem to elucidate the mechanism of these phenomena.

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Seasonal distribution of births of 9, 868 schizophrenic patients and 1, 795 manic-depressive patients in Tokyo born during the period 1841-1960 and treated at two hospitals during the period 1879-1976 was investigated by year of birth and sex.
Both schizophrenic and manic-depressive birth distributions showed deviations from the control. How the distributions deviated was different by year of birth and sex of the patients. The deviations per se, could be seen in both male and female patients.
Considering the fact that birth seasonality of psychotic patients varied by period of birth and sometimes by sex, it is suspected that those“endogenous”mental diseases may be prepared by plural exogenous seasonal epidemic factors which act on fetal or neonatal stages and some of which may interact with sex difference.

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