岡山医学会 Acta Medica Okayama 0030-1558 80 7-8 1968 ジステンパーウイルス感染培養細胞の有絲分裂像について 875 880 EN Jutaro Tawara The present paper will report about the mitotic phases of the cells infected with canine distemper virus. Namely, FL cells and MDCK cells which have formed inclusion bodies after inoculation of canine distemper virus showed normal mitosis and inclusion bodies were transfered to the dauther cells. Mitosis was observed only in the monounclear cells and not in the multinucleated giant cells infected with this virus. No potential conflict of interest relevant to this article was reported.

岡山医学会 Acta Medica Okayama 0030-1558 80 7-8 1968 憂うつ病の身体症状 内分泌を中心として 867 873 EN Mutsutoshi Kohsaka Takashi Nagao Shigeru Kikui 1) 憂うつ病の身体的徴候を特に内分泌所見を中心として考察した. 2) 憂うつ状態では尿の17-KS分劃が減少し,血清の17-OHCS分劃の増加が見られる.憂うつ症にTestosterone系のものを与えると症状が改善したり,又ACTH注射やCortisol投与で悪化する事実から,憂うつ状態の成立には性腺系ホルモンの減少が関係していると考えられる. 3) 憂うつ病になる者には性腺系ホルモン代謝に潜在的な弱点があるのではなかろうかと思われる. No potential conflict of interest relevant to this article was reported.

岡山医学会 Acta Medica Okayama 0030-1558 80 7-8 1968 Adenovirus 12型に関する研究 第Ⅲ編 年令別ハムスターに於ける Adenovirus 12型の増殖性について 861 865 EN Kozo Fujita Since the discovery that adenovirus type 12 inoculated into newborn hamsters develop tumor in a high percentage of the animals, other types 18, 7 and 31 were also found to induce tumors to a lesser extent. In the elucitaion of the mechanism of carcinogenesis due to virus the study of changes in virus growth appears to be most important. For this reason, adeno-virus type 12 was inoculated to hamsters ranging in age from newborn to 14, 45 and 65 days old. These animals were sacrificed at diffe ent time intervals after the inoculation, and the kidney, liver, peritoneum and lung were removed, and examined for virus. For the detection of virus in these organs, the method of s'ant agar culture was employed as it was found to be simple and easy to manipulated, as reported previously. As a result it was found that: 1. In the inoculation of this virus to newborn hamsters, the virus could be isolated from various organs up to l1 days after the inoculation. In this instance, the virus was found to be most active in the organs 1-7 days after the inoculaticn, indicating some proliferation of the virus. 2. With the hamsters 14 days old, it was possible to isolate the virus for 3 days after the inoculation. 3. In the case of animals 45 and 65 days old, the virus disappeared within 24 days of the inoculation. 4. In the inoculation of the virus to newborns, the tumor growth was noted at autopsy 30 days later, while no tumor could be observed in those animals over 14 days old. No potential conflict of interest relevant to this article was reported.

岡山医学会 Acta Medica Okayama 0030-1558 80 7-8 1968 Adenovirus 12型に関する研究 第Ⅱ編 Adenovirus 12型の寒天斜面組織培養法及び単層組織培養法による増殖について 857 860 EN Kozo Fujita No potential conflict of interest relevant to this article was reported.

岡山医学会 Acta Medica Okayama 0030-1558 80 7-8 1968 Adenovirus 12型に関する研究 第Ⅰ編 Adenovirus 12型の3種の組織培養法による増殖性について 849 855 EN Kozo Fujita It is known that adenovirus type 12 nduces tumor in a high proportion of young hamsters, and also other types of adenoviruses do so to some extent. In the study of this virus the problems are posed the survival of the virus inoculated in animals, the presence or absence of the virus in the tumor developed by the virus, and the isolation of virus from man. It is, therefore, necessary to find out some appropriate methods to detect even a minute quantity of virus. With this view in mind, the authors conducted a series of experiments by the following three methods of successive tissue cultures using monolayer HeLa cells in culture infected with adenovirus 12 for the period of 7 days for each generation to see which of the three methods is most suitable. The results of this study are briefly summarized as follows 1. The tissue culture conducted for generations of HeLa cells with freezing-thawing techniques: The cells growing in monolayer in the test tubes were infected with adenovirus type 12 and cultured for 7 days as one generation. At the termination of each culture period the medium was changed with 1ml of fresh one. The first generation cells were frozen and thawed, cent-rifuged, and then the supernatant was placed into new monolayer HeLa cells. Subsequently, tissue culture was continued for generation after generation. In the doses of 1, and 10(-1) TCID(50) of virus used, 3 generations were needed to confirm proliferation of virus on the ground of cellular degeneration, and in the doses of 10(-2), 2×10(-3), and 10(-3) TCID(50), 4 generations were needed. 2. Virus culture through successive generations of infected cells: As in the preceding experiments the infected HeLa cells were cultured for 7 days, and after dispersing the cells in monolayer with trypsin solution, this first generation was divided into two equal parts, each of which was placed in the test tubes and cultured. Successive cultures were conducted in similar manner. The growth rate of virus in this series proved to be about the same as in the foregoing experiments. 3. Virus culture on slant agar: As in the preceding experiments the infected HeLa cells cultured for 7 days were dispersed with trypsin solution. This cell suspension of the first generation was centrifuged and the sediment, divided into about five equal masses of cells, was placed on slanted surface of agar, and cultured. Then one half the amount of the cells growing on the agar for 7 days was cultured again on the agar. The other half of the sediment was frozen-thawed with 1ml of the medium, centrifuged, and the supernatant was placed in the new monolayer to determine the proliferation of the virus. This method also gave the results not so different from those by the two preceding methods. From these results it is concluded that the tissue culture conducted on the slant agar is the most suitable method for the detection of virus growth because it is easy to manipulate and simple to maintain successive generations. No potential conflict of interest relevant to this article was reported.

岡山医学会 Acta Medica Okayama 0030-1558 80 7-8 1968 担癌マウスにおける下垂体前葉・副腎皮質の組織学的研究 第Ⅱ編 副腎皮質組織について 841 848 EN Akira Yamagata The author made cytological observations of the adrenal cortex in mice with leukemia or mammary cancer. The results of this experiment were as follows: 1. Adrenal glands of mice were, in general, hypotrophic and sudanophilic droplets which were also Schiff-positive or Schultze-positive increased markedly in number in zona fasciculata et glomerulosa. 2. In mice with mammary cancer, adrenal glands were hypertrophic and sudanophilic droplets which were also Schiff-positive or Schultze-positive decreased relatively in number in zona fasciculata et glomerulosa. 3. The foregoing evidence indicates that the adrenal cortex in leukemia mice is hypofunctional and in mammary cancer hyperfunctional. No potential conflict of interest relevant to this article was reported.

岡山医学会 Acta Medica Okayama 0030-1558 80 7-8 1968 担癌マウスにおける下垂体前葉・副腎皮質の組織学的研究 第Ｉ編 脳下垂体前葉組織について 835 840 EN Akira Yamagata In the cytological observations of the hypophysis in mice with leukemia or mammary cancer, the author made the classification and calculation of epithelical cells of mouse anterior hypophysis. The results of this experiment were as follows: 1. In the pituitary of mice with leukemia, acidophilic cells decreased in number, while the basophilic particularly chromophobic ones increased in number. 2. In the pituitary of mice with mammary cancer, acidophilic and basophilic cells decreased in number, while the chromophobic ones increased in number. 3. From these findings it is assumed that the hypophyseal function of mice with leukemia or mammary cancer is hormone-unbalanced. No potential conflict of interest relevant to this article was reported.

岡山医学会 Acta Medica Okayama 0030-1558 80 7-8 1968 農薬Drin剤の循環器系機能に及ぼす作用 第3編 Drin剤の犬血圧に及ぼす作用及びDrin剤中毒家兎の心電図学的研究 815 834 EN Kojiro Hyodo By examining the blood pressure in dogs and electrocardiogram in rabbits treated with drin compounds, the author obtained the following results: 1. Drin compounds, when injected intravenously in dogs, cause a transitory lowering of blood pressure. But when generalized convulsions occur, blood pressure rises and becomes markedly labile. 2. Administration of atropine does not inhibit the effect of drin compounds on blood pressure. 3. Simultaneous administration of dieldrin and adrenaline inhibits blood pressure lowering effect of dieldrin. 4. Ganglion blocking agents such as chlorpromazine and tetraethylammonium do not inhibit the effect of dieldrin on bood pressure. 5. Administration of drin compounds slows the heart rate in rabbits. 6. In rabbits given drin compounds, electrocardiograms often demonstrate depressed ST segments and low to inverted T waves. 7. In rabbits given a large amount of drin compounds, electrocardiograms may show left bundle branch block, atrial fibrillation, ventricular premature beat and multifocal idioventricular rhythm. 8. In rabbits treated with a small dosage of drin compounds for a prolonged period, electrocardiograms show no significant changes. No potential conflict of interest relevant to this article was reported.

岡山医学会 Acta Medica Okayama 0030-1558 80 7-8 1968 農薬ドリン剤の循環器系機能に及ぼす作用 第2編 ドリン剤の蛙心に及ぼす作用 803 813 EN Kojiro Hyodo By studying the action of drin compounds on isolated frog heart (Straub-Fuhner's method), the author obtained the following results: 1. In the case of dun compounds at a low concentration there occurs a slight decrease in the amplitude of heart beats. 2. At a high concentration, atrioventricular block and low amplitude are obserbed. Such changes are more prominent at a higher concentration, which eventually leads to diastolic cardiac arrest. 3. Premedicaticn of atropine does not reduce the suppressive action of dieldrin. 4. When atropine is given to the heart after exposure to dieldrin, an increase in the amplitude and continuance of heart beats may be seen. 5. Application of adrenaline previous to dieldrin, does not influence the decrease in the amplitude of heart beats. 6. When adrenaline is applied just prior to the cardiac arrest by dieldrin, heart beats are maintained with an increase of their amplitude. 7. It is concluded that drin compounds are not cholinesterase blockers such as alkylphosphates. No potential conflict of interest relevant to this article was reported.

岡山医学会 Acta Medica Okayama 0030-1558 80 7-8 1968 農薬ドリン剤の循環器系機能に及ぼす作用 第1編 ドリン剤の末梢血管に対する作用 785 801 EN Kojiro Hyodo By studying the action of drin compounds on the peripheral blood vessels (Krakow-Pissemiski's method) of the rabbit ear, the author obtained the following results: 1. All the drin compounds (dieldrin, aldrin and endrin) induce a transitory dilatation of the extirpated peripheral blood vessels. But at high concentrations vasoconstriction is observed. 2. Atropine does not counteract the vasodilation by dieldrin. 3. With respect to the dilatation of peripheral blood vessels adrenaline acts antagonistically in contrast to the additive effect of acetylcholine. 4. Drin compounds act antagonistically against the vasoconstriction by barium chloride. It is considered that the mechanism of vasodilatation by these compounds is based on their direct action on the contractible muscle cells of the vessel walls No potential conflict of interest relevant to this article was reported.

岡山医学会 Acta Medica Okayama 0030-1558 80 7-8 1968 サポニンの細網内皮に及ぼす影響に関する研究補遺 第1篇 サポニン中毒家兎における肝および骨髄類洞内皮の再生 765 774 EN Taizo Nakamura It was reconfirmed that a sublethal dose of saponin produces disintegration of the sinusoids in the liver and bone marrow of rabbits. After destruction of the sinusoids, restitution of endothelial cells of the sinusoidal walls was studied. It was revealed that the endothelial walls of newly formed sinusoids are constituted of reticular cells which come from the regenerating haematopoietic areas. Although stellate cells of Kupffer in the liver and splenic macrophages undergo extensive proliferation during the earlier pariod of restitution after saponin poisoning, there is no evidence to indicate that these cells paticipate in the reconstruction of sinusoids in the liver and bone marrow, paticularly the latter. No potential conflict of interest relevant to this article was reported.

岡山医学会 Acta Medica Okayama 0030-1558 80 7-8 1968 胃潰瘍症の血液成分の変化に関する研究 743 763 EN Kimiyasu Sato There have been many reports on the alterations in the blood constituents levels of patients with stomach ulcer. Some reporters stated anemia, hypoproteinemia, hypoalbuminemia, decreased serum cholinesterase activity and serum iron in the cases of stomach ulcer; but other noticed that levels of blood constituents in patient with stomach ulcer were amost within normal range. An investigation of the difference between the levels of the blood constituents of the normal and of the stomach ulcer cases was attempted. One hundred and fifty one cases of normal, 286 cases of stomach ulcer and 266 cases of stomach cancer were examined. The measured blood constitueuts were RBC, hemoglobin concentration, hematocrit, WBC and blood group. The serum constituents such as cholinesterase, alkaline phosphatase, cholesterol, glutamic pyruvic transaminase, phenol turbidity test, amylase, non-protein nitrogen, sugar, iron, copper, protein and its fractions, mucoprotein and its fractions and lipoprotein were also determined. The significant changes were statistically discussed. Decreases of RBC, hemoglobin concentration, Ht, serum cholinesterase activity, serum iron, serum albumin, A/G ratio and mucoprotein-albumin, and increases of WBC, serum GFT activity, serum amylase activity, serum NPN and globulin fraction of serum protein were noticed in the cases of stomach ulcer. It is supposed that anemia and decreased serum iron are due to the continuous bleeding from ulcer, hypoalbuminemia and decreased serum cholinesterase activity and increased GPT activity are to general deterioration by maluntrition and liver damage accompanied with stomach ulcer. Increase of serum amylase activity and serum NPN may be the sequences of pancreatic and renal involvements, the latter might be followed by the ulcer hemorrhage and dehydration. The blood constituents levels in the cases with stomach ulcer which needed the operation showed more advanced anemia and hypocholinesterasemia than in the whole ulcer cases. In the cases with large ulcer, decreased cholinesterase activity and increased NPN were prominent. The comparison of blood levels in the stomach cancer with in the stomach ulcer revealed that decreased RBC, hemoglobin concentration, serum cholinesterase activity, serum iron, gamma-globulin fraction and mucoprotein-albumin and increased alkaline phosphatase activity were significant in the group of stomach ulcer. The blood constituents levels in stomach ulcer group were situated between normal and stomach center group in regard to anemia, general deterioration and liver damage; but in the cases of large ulcer, some constituents such as serum cholinesterase, serum amylase and serum NPN were in worse condition than in the stomach cancer cases. Relationship between stomach ulcer and liver function disturbance was significantly observed in blood spectrum. Anemia, malnutrition and accompanied gastritis with stomach ulcer may induce secondary chronic liver damage, but severe liver disorder occurs rarely in the cases with stomach ulcer. No potential conflict of interest relevant to this article was reported.

岡山医学会 Acta Medica Okayama 0030-1558 80 7-8 1968 胃ポリープ症の臨床検査成績についての検討（特に血液成分の変化に関して） 721 742 EN Michio Kobori No potential conflict of interest relevant to this article was reported.

岡山医学会 Acta Medica Okayama 0030-1558 80 7-8 1968 蛋白同化ステロイドのコレステロール代謝に及ぼす影響 第2編 脱コレステロールの機構 709 720 EN Akemitsu Ishii In order to elucidate the mechanism operating during the hypocholesterolemic action after the administration of anabolic steroids, cholesterol and bile acids were determined in the serum, bile and liver. About 100 male dogs of 10kg body weight were used at the experimental animals. The animals were divided into 3 groups: The first group was normal healthy dogs, the second was the dogs blocked the reticuloendthelial system with china ink, and the third was the dogs given carbon tetrachloride. Pyridoxal phosphate was given simultaneously to the dogs in about a half of the test animals. The results obtained were as follows; a) A reduction of serum cholesterol was observed in the healthy dogs by the administra tion of the anabolic steroido, the increased uptake of cholesterol into the liver as well as increased synthesis of trihydroxy cholanic acid and dihydroxy cholanic acid from cholesterol followed with increased excretion into bile were thought to be responsible for the reduction of serum cholesterol. b) The anabolic steroid had no hypocholesterolemic action when liver cell wasdamaged or reticulo-endothel system was blocked. c) The shift of cholesterol from blood the liver is related to liver cell and reticuloendothel system. d) Pyridoxal phosphate used with anabolic steroid resulted in no excretion of trihydroxy cholalic acid and dihydroxy oholalic acid in bile, be it seen when only the latter was administered. Pyridoxal phosphate is competitive to anabolic steroid. e) Pyridopal phosphate used with anabolic steroid had no such effect when the liver cell was damaged or reticulo-endothel system was blocked. No potential conflict of interest relevant to this article was reported.

岡山医学会 Acta Medica Okayama 0030-1558 80 7-8 1968 蛋白同化ステロイドのコレステロール代謝に及ぼす影響 第1編 脱コレステロールの場 701 707 EN Akemitsu Ishii Anabolic steroids such as H.M.D., 19 N.P.P. were given to 23 patientents with stomach diseases, then the change of cholesterol level and liver function test was investigated to assess the effect of the anabolic steroids on the cholesterol metabolism Simultaneously pyridoxal phcsphate was given to 5 patients and the effects was analyzed. The results obtained were as follows; a) Administration of the anabolic steroids showed no significant in serum protain level, A/G ratio, the serum flocculation tests. The level of serum bilirubin was unchanged. But the Bromsulphalein retention rate and transaminase activities were increased, the serum level of cholesterol was strikingly decreased. Alkaline phosphatase was slightly decreased though it occured within normal range. b) Administration of the anabolic steroids with pyridoxal phosphate resulted in the no appreciable change in cholesterol level. The increase of transaminase activities was not observed. This phenomenon was interpreted as an conpetitive action was operating between the mechanism in which cholesterol level reduce in one side and the transaminase activities increase in the other. c) In the experiment of the dogs given H.M.D., a reduction of the serum cholesterol level was observed. The gradient was in proparation to the time after the administration. The highest level was in the partial vein, the next was in the hepatic artery, and the lowest was in the hepatic vein. From the results obtained here, is was concluded that hypocholesterolemic action occurs in the liver when the anabolic steroids were given to the patients. No potential conflict of interest relevant to this article was reported.

岡山医学会 Acta Medica Okayama 0030-1558 80 7-8 1968 移植動物癌腫瘍抗原に関する研究 第2編 Ehrlich腹水癌腫瘍リボゾーム蛋白の抗原性について 691 700 EN Yasuo Tadatomo Antigenicity of ribosomal protein in Ehrlich ascites tumor and the biochemical characters were studied. The cytotoxic activity of immunized male dd-mice serum globulin was proved by cell culture test. Ribosomal protein was moved electrophoretically to basic side than that of serum γ-globulin, and the protein concentraticn was adequate for maximal antigenicity 1 mg per mouse. The antitumor activity of immunized εerum globulin was most elevated at 25 th day after immunization, and that of lymph nodes and spleen were at 10 th day. The antitumor activity of immunized serum globulin was mainly existed in γ-globulin fraction, but also contained in α-and β-globulin fraction. No potential conflict of interest relevant to this article was reported.

岡山医学会 Acta Medica Okayama 0030-1558 80 7-8 1968 移植動物癌腫瘍抗原に関する研究 第1編 Ehrlich腹水癌腫瘍組織低密度リポプロテインの抗原性について 677 689 EN Yasuo Tadatomo Antigenicity of insoluble lipoprotein (low density lipoprotein) in Ehrlich ascites tumor and its biochemical characters were studied. The cytotoxic effect of immunized male dd-mice serum globulin was examined by cell culture technique. The insoluble lipoprotein used as antigen was moved electrophoretically similar with serum β-lipoprotein, and the maximal antigenicity was obtained by administration of 1 mg protein concentration per mouse as antigen. The cytotoxic effect was mainly existedin γ-globulin fraction. The antitumor activity was most elevated at 25 th day after immunization with low density lipoprotein, and the effect was decreased gradually after 30 th day. The globulin fraction in lymph nodes and spleen was showed the highest cytotoxic activity at 10 th day after immunization. No potential conflict of interest relevant to this article was reported.

岡山医学会 Acta Medica Okayama 0030-1558 80 7-8 1968 小脳の酵素組織化学―特にプルキンエ細胞のα-グリセロ燐酸脱水酵素と「固定の問題」をめぐつて― 665 676 EN Iwao Tokunaga (1) ダイコクネズミ及びヒト,ネコの小脳について,乳酸脱水素酵素(LDH),コハク酸脱水素酵素(SDH),α-グリセロ燐酸脱水素酵素(α-GPDH)活性を組織化学的に検索した. SDH,α-GPDHの検出にあたつてはintermediatorとしてmenadione (MD)を反応液に添加した. 新鮮凍結クリオスタット切片にて,LDHは顆粒層の“gloneruli cerebellosi”に相当して最も強く,分子層ではformazan顆粒はびまん性に形成されて反応は顆粒層よりやや弱くPurkinje細胞(P-細胞)は核を除いて細胞体に強度～中等度の活性を示し,白質には活性はほとんど証明されなかつた. SDHは全体としてLDHの反応態度に似た像を示し,顆粒層に最も強く,ついでP-細胞層,分子層の順で活性が認められ,白質にはほとんど証明されなかつた. α-GPDH反応は,顆粒層,分子層においてはLDH, SDHとほぼ同じであるが,P-細胞層にはformazanの形成がほとんどなく,あたかも顆粒層と分子層の間に空隙がある様な像を示した.白質には活性はほとんど証明されなかつた,これらの所見は,これまでの報告にほぼ一致するものである. (2) 上記酵素活性の検出にあたり,新鮮凍結クリオスタット切片とともに,同一材料について組織塊をまず10%冷フォルマリンで固定した後に作製した凍結切片をあわせて使用した. SDH,α-GPDH, LDHともに反応は全般に減弱されるが,LDHの反応の減弱の度合は他の2者にくらべて少ないようであつた. ここで注目すべきことは,非固定切片のP-細胞層において,α-GPDHの活性がほとんど認められなかつたにもかかわらず固定切片のP-細胞には反応が認められ,しかもformazan形成は他の部よりもむしろ強度であつた点である.この事実は酵素組織化学における方法の選定や結果の判定にあたつては常に慎重な配慮が要求されることを示す現象であるとみなされ,この点に着目し特に固定の問題をめぐつて諸種の条件を実験的に設定してしらべた. (3) フォルマリン固定切片における反応には, i) 固定時間の長さによる著明な差異がみられない. ii) pHの変化による影響が少ない. iii) 特異的抑制剤による影響がみられない. iv) MDの存在が不可欠である. v) SH-基の関与がある. vi) Nitro-BTの組織への吸着性の増強が関連している. ということを認めた. このことからフォルマリン固定切片に見られる反応は,Nitro-BTの組織蛋白との結合性を前提とて,SH-groupとMDとが関与している非酵素的作用の結果であることを推論した. (4) 小脳組織でP-細胞が他の細胞要素と異なり,非固定切片においてα-GPDH活性をほとんど示さないこと,およびフォルマリン固定によりP-細胞に非酵素的なNitro-BT還元が著明にあらわれることは,P-細胞の細胞化学的特異性の一面を示すものであろう. No potential conflict of interest relevant to this article was reported.

岡山医学会 Acta Medica Okayama 0030-1558 80 7-8 1968 脳におけるコルチコイド代謝 647 663 EN Shigeru Kikui By the clinical studies on steroid hormones in endogenous mental diseases so far carried out, we have found that it is the steroids belonging to 17-KS rather than 17-OHCS which are associated with the mental excitation. In view of this, we attempted a study about the brain metabolism on testosterone which is an important precursor of 17-KS with a strong biological activity. The materials used were the brain of Donryu rats and human beings. Each of these brain tissues was homogenized in ten-fold volumes of 1/15M phosphate buffer solution. Then, taking 2ml of the brain phosphate buffer homogenate or 2ml each of 1/15M phosphate buffer suspension of the supernatant containing nuclear, mitochondrial or microsomal fraction, prepared from 1g rat brain, the incubation was conducted in the air at 37℃ for 60 minutes after adding 0.1μc [4C(14)] testosterone, 0.2 mg cold testosterone, 0.5 mg each of NAD and NADP as cofactor, and 10 mg nicotinamide. Then, metabolites were extracted, applied on the florisil column, and 2% methanol-chloroform fraction was collected and dried. For the control groups the brain tissues inactivated by heating were employed. Each of the specimens thus obtained was applied on the Silicagel-G thin layer chromatography (TLC), and metabolites were isolated and identified by the 2% NGS gas chromatography. After the TLC-autoradiography the portions that coincided with the radioactive spots was taken and each of these chromatograms was applied to the liquid scintillation counter and the percentage of the conversion of metabolites was calculated from respective radioactivity. 1) Both from the rat brain and the human brain on the TLC (chloroform-acetone-methanol, 90:7:3, developed for 15 cm) there are seen four principal spots, and designating these spots as I, II, III and IV starting from the original point of application, the spot II is testosterone, proving that 90-95% or more of testosterone added has not been metabolized. 2) The spots I and III are minor metabolites, of which I is the substance like ll-OH-Etio-cholanolone. and III is an unknown substance. The conversion rate of each is only about 0.2%, proving to be of no significant value. 3) The spot IV is a major metabolite, and on the further TLC (chloroform-acetone, 85:15, developed for 55 cm) it separated itself into two spots, each of which has been identified to be Δ(4)-androstene-3, 17-dione and dihydrotestosterone. The conversion rate of the two together is 2.46% with the rat brain and 2.29±0.73% with the human brain in average, and without addition of co factors it is decreased to 1.80% and O.5% respectively. 4) The activity of the enzymes responsible for the major metabolite formation, namely, 17β-hydroxysteroid dehydrogenase and 5α-reductase, is detectable in every fraction of the rat brain, but it is highest in the telencephalon mitochondrial and fairly high in the supernatant fraction, and the conversion rate from testosterone is about 0.5% in each case. After all, since the brain is not a metabolic organ nor a target organ, the metabolism of testosterone is extremely low, nonetheless, looking it from the aspect of its potency, we cannot rule out its significance. A further problem which we have to solve will be the role played by the hormones responsible for mental excitation, by investigating the correlation of the brain site to the metabolism of steroids including testosterone. No potential conflict of interest relevant to this article was reported.