The effect of CDP-choline on the formation of pulmonary surfactant was studied histologically and biochemically. The results obtained are summarized as follows:
(1) 1,2 -¹⁴C-CDP-choline (10 μCi) was injected i ntraperitoneally into adult Sprague-Dawley rats. After 1,3,6 and 15 hours, the lungs were extirpated and subjected to histological and radioautographical studies. It was revealed that, on a carbohydrate resin section of 6-7 μthickness, the radioactive granules derived from 1,2-¹⁴C-CDP-choline were found in the alveolar epithelial cells.
(2) The pregnant rats were devided into two groups. To the first group (15rats), CDP-choline (50mg/kg/day) was administered intraperitoneally every day from the 10th gestational day onwards; the second group (20rats) had no CDP-choline administered. The parent rats were decapitated and the level of phosphatidylcholine in the fetal lungs was measured, i. e., extraction of lipids, isolation of the phosphatidylcholine by chromatography on aluminum oxide and on thin layer plates followed by determination of its phosphorus content. It was found that the phosphatidylcholine content of the CDP-choline-treated group was about 45% higher between the 19th-21st gestational days and about 15% higher between the 16th-17th days than that of the control group.
(3) A part of the fetal lungs described above was also examined by light microscopy. The tissue was fixed in glutaraldehyde and osmium tetroxide and embedded in epoxy resin. Sections (1 micronthickness) were obtained using glass knives as a Porter-Blum Sorvall MT-2 ultramicrotome. The sections were stained with toluidine blue, periodic acid-Schiff (PAS), or paraphenylene diamine. These microscopic techniques were found to be more effective than electron microscopy in observing general distribution features of the granules in the alveolar wall. Compared to the control group, the CCP-choline-treated group was demonstrated to have more inclusions in Type I I cells of the alveolar epithelium. It was also shown that this tendensy was more marked after the 19th gestational day than before the 17th day.
(4) From the results of these animal experiments, the author assumes that it would have a much marked effect on a human fetus if it were applied after the 32nd gestational week it would promote the surfactant formation and would also possibly prevent or treat the respiratory distress syndrome (RDS) at this stage

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Cytogenesis of human fetal pancreas has been studied electron microscopically. In a 10 weeks fetus, hardly any indication for differentiation of the pancreatic epithelium cells has been observed. Neither α and β granules nor zymogen granules have been found in the cytoplasm, Golgi apparatus is not well developed and rough endoplasmic (rER) reticulum was scarecely observed. The cytoplasm is filled with a large member of glycogen granules and with free polyribosomes.
In a 13 weeks fetus, differentiated exocrine cells start to appear which are characterized by well developed rER in paralell lamellar array or in whorle structure, by increased amount of Golgi membrane and by a number of zymogen granules. In a 22 weeks fetus, almost all the exocrine cells have been differentiated and the cytoplasm is filled with expanded profils of rER. In some cells rER is transformed to vesicular form and a number of zymogen granules are accumulated in the apical cytoplasm, suggesting extensive synthesis and storage of the secretory proteins,
Differentiated endocrine cells also appear around 13 weeks of gestation, and α and, β granules have been found in the fetus of 13 weeks and 18 weeks, respectively.

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A study was made of the mechanism of ether, halothane and methoxyflurane functioning on the rabbit central nervous system with the following results:
1. All the drugs employed in arousal reaction following stimulation of the brain stem reticular formation, Ether and halothane acted more markedly on what was recorded from the cerebral cortex than on what was recorded from the hippocampus. Halothane inhibited arousal reaction in the cerebral cortex most markedly, followed by methoxyflurane and ether in order.
2. Against evoked muscular d ischarge in the rabbit fore and hind limbs following stimulation of the brain stem reticular formation, methoxyflurane showed the heighest threshold, followed by halothane and ether in order. Halothane and methoxyflurane showed little difference in an elevation of the threshold between the fore limbs and the hind limbs. But ether resulted in more elevation in the fore limbs than in the hind limbs.
3. Methoxyflurane little influenced the wave type of evoked muscular discharg e due to stimulation of the brain stem reticular formation. But ether and halothane tended to develop the tonic type muscular discharge.
4 Methoxyflurane inhibited evoke d muscular discharge due to stimulation of the cerebral cortex most markedly, followed by halothane and ether in order. Ether caused a change of the wave type of evoked muscular discharge from the tonic type to the TP type, while halothane and methoxyflurane showed no such obvious change.
5. Methoxyflurane inhibited evoked muscular discharge due to stim ulation of the hippocampus most markedly, followed by halothane and ether in order. Ether caused a change of the wave type of evoked muscular discharge into the phasic type, but halothane and methoxyflurane showed no such obvious change.
6. Ether markedly acted on the pyramidal truct, haloth ane and methoxyflurane acted on the pyramidal truct, but they acted more markedly on the extrapyramidal t r uct.

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腸管の輸送運動におよぼす薬物の影響を検討する際に用いられている方法には,van Liereら,Reyneら, Levqらが報告していうように,炭素末や色素などの着色物質を経口投与し,その腸管内移行を追跡する方法や,Groteら,寺田ら,MillerらあるいはLau が報告しているように,排泄される便の形状,排便量,排便回数などを観察する方法tおよびそれらの改良法があり,いずれも外科的侵襲を加えることなく経口的に投与された物質の移動を基準にして,腸管の輸送運動におよぼす薬物作用を知るために用いられ,特に濾下薬のスクリーニングあるいは効力検定に用いられている.
著者らは下剤のスクリーニングを行なつた際,これらの方法に基いて検討を行なつたが,すでに臨床的に明らかにその効果が認められている薬物についても,実験的な効果を数量的に表わすことが極めて困難であることに気付いた.元来,緩下薬は腸管の輸送運動が低下した状態を改善し,正常な機能を回復させることを目的として使用されるべきものであつて,すでに正常な輸送運動を有する腸管の機能を正常以上に充進させる作用は期待されていないはずである.
本実験ではtvan Liereらが報告し,田中らによって改良された方法を用いて,緩下作用をもつとされている薬物および緩下作用を有するか否かをスクリーニングする必要のある薬物について効力検定を行なったが,あらかじめAtropineおよびPapaverineを同時投与し,腸管輸送運動を一旦低下させ,検討すべき薬物がこの低下した機能をどの程度正常に近づけ得るかを目標として実験を行なった.

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It is well documented that the limbic system influences upon the cortical photic evoked potentials via the hypothalamus. Since the different frequency parameters of the stimulation to the limbic system produce various effects upon the cortical photi c evoked potentials, it can be predicted that the different frequency stimulation to various parts of the hypothalamus will produce different effects upon the cortical photic evoked potentials.
Fifty-five ra bbits were utilized for the purpose of this experiment. In the mammillary body, ventromedial nucleus, dorsomedial nucleus, and posterior part of the lateral hypothalamic area, the conditioning electrical stimulation with high frequenc y (100 Hz) attenuated the amplitudes of the cortical photic evoked potentials, while that of low frequency (5 Hz) facilitated them. On the contrary, the condition ing electrical stimulation to the preoptic area, suprachiasmatic and supraopt ic nuclei, field H of Forel, anterior part of the lateral hypothalamic area and the optic tract produced fixed effects upon the cortical photic evoked responses irrespective to the frequency parameters.
These facts imply that the impulses from the limbic system, mainly pass through the posterior hypothalamus where the sympathetic and parasympathetic system s are intermingled and are activated with high and low frequency impulses respectively, It is interesting to note that these bivalent reactions by different frequency parameters were neutralized between 40 to 50Hz frequencies. on the contrary, fixed eff ects upon the cortical photic evoked potentials in the anterior hypothalamus including preop tic are irrespective to the frequency parameters of the stimulation.

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