Hepatic and cerebral coenzyme a contents after intravenous injection of coenzyme a in rats

Summary Hepatic CoA concentrations and contents were significantly higher in rats having received i.v. CoA injections than in control rats. Maximum hepatic CoA concentrations were found 0.5–1 h after injection. In rat brain, no increase in CoA concentration was detected after i. v. injection of CoA.Acknowledgments. We thank MissV. Godly and MissA. M. Reber for excellent technical assistance. This work was supported by grants from F. Hoffmann-La Roche & Co., AG, Basel.     

Neurochemical correlates of alloxan diabetes: I. Ribonucleic acid and protein levels of amphibian brain

Summary The levels of RNA and protein were higher in the brain of alloxan-administered frogs. It is possible that alloxan is responsible for the protein changes in the brain as the protein levels were higher 48 h after alloxan injection than after 96 h. Acknowledgment. I am grateful to the late Prof.K. Pampapathi Rao for encouragement and facilities.     

Einige Bemerkungen zur Form und zum Relief der Schädelausgüsse vonPithecanthropus und vonSinanthropus

Summary The general morphological and the fissural character ofDubois' andKoenigswalds Pithecanthropi andBlack's Sinanthropus (E) strongly suggest that thePithecanthropus brain had more anthropoid features than theSinanthropus brain.     

Further studies on the effect of 6-hydroxydopamine in retinal development

Summary Neonatal albino rats treated with 6-hydroxydopamine revealed depletion of rhodopsin and monoamine oxidase in their retinas.Acknowledgments. The author wishes to dedicate this paper to his family for their continuous support and to ProfessorsA. K. S. Ho andD. B. Meyer for their understanding and friendship.     

Graft-versus-host reaction and lymphoid organs in normally fed and protein-deprived rats

Summary Lymph node graft-versus-host reaction (GVHR) induced by parental splenic lymphocytes inoculated into hind foot pads of F-1 hybrid rats is correlated with the state of the thymus and the spleen of the recipients. This may explain the depression of the reaction after protracted protein deprivation. Furthermore, GVHR provokes mainly in normal rats a reduction of thymus and spleen possibly due to a T-cell transfer to the grafted area.I thank Mrs.M. Cl. Gonzalez and Mr.D. Soulas (C.N.R.S.) for their skilled technical assistance.     

Intraspezifische Unterschiede der relativen Hirngrösse beim Löwen (Panthera leo L.)

Summary Different stages of brain evolution expressed by the allometric relation of³ brain capacity and basal length of the skull are shown to be existent in the speciesPanthera leo. Whereas Asiatic lions obviously have the same level of brain size as leopards (Panthera pardus), African lions have higher brain capacities. A third level seems to be represented by the upper pleistocene American lion,Panthera leo atrox. These results permit us to reject some conceptions ofHerre andRöhrs ¹³ concerning the quantitative expression of mammalian brain evolution.     

Increased membrane-bound polyribosome fraction in the brains of rats with hereditary diabetes insipidus

Summary Rats homozygous for hypothalamic diabetes insipidus were found to have a significantly higher concentration of membrane-bound polyribosomes thant their heterozygous littermates. There was no difference in the concentration of free polyribosomes.     

Proestrous gonadotropin levels in thyroparathyroidectomized female rats

Summary Intact and TPTx animals showed the expected afternoon increase in serum LH, FSH and prolactin levels. But the afternoon increase in serum LH levels in TPTx rats was less than that observed for intact animals (p<0.01). Neither serum prolactin nor FSH levels were altered by TPTx.The excellent technical and secretarial assistance ofS. Hemelt andD. Landman is gratefully acknowledged.     

Structure-activity relationships of cyclic acetylcholine analogues of the piperidinol and thiacyclohexanol series

Summary The hydrochlorides and methiodides of 1-methyl-3- and 4-acetoxypiperidine and their sulphonium analogues are cholinergic agonists. They are substrates for acetylcholinesterase. The sulphonium compounds have a 78(-524)-fold higher activity than its nitrogen analogues.We thank the German Research Association for support of this work, and MissChristiane Roth for her valuable assistance in carrying out the investigations.     

Neurochemical correlates of alloxan diabetes: Protein and ribonucleic acid levels in the different regions of the rat brain

Summary The levels of protein and ribonucleic acid in the cerebrum, cerebellum, optic lobes and medulla oblongata of normal and alloxan-diabetic rats were measured. In general, the protein content and levels of ribonucleic acid in the broad compartments of the brain of rat decreased during diabetes.Acknowledgment. The authors thank Dr.A. R. Kasturi Bai, Head of the Department of Zoology, Bangalore University, for providing facilities during the study.     

Production d'anticorps 7 S et 19 S chez des Rats d'âge différent

Summary Antibodies produced following injections of a proteinic antigen emulsified in Freund's adjuvant were studied by the passive hemagglutination test in some lots of WCF rats, varying in age. It is shown by treating sera with mercaptoethanol that older animals produce less 7 S antibodies than younger ones, and that, despite this difference, rats remain able to elaborate seric antibodies at relatively high rates during their senescence period.

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Service du DocteurH. Kaufmann.     

Konstante Stromwirkung und « funktionelle Polarität »

Summary Scheminzky found that the effect produced by passing a constant current through a frog depended on the direction of the current. While a descending current (directed from heat to foot) produced paralysis, an ascending current produced convulsions.Scheminzky believed that it was impossible to explain this phenomenon in any other way than by a functional polarity, involving a special microstructure in the cells of the spinal cord.—We found that the observed effect is in no way connected with the direction of the current, and that, on the contrary, it depends exclusively upon the electrical charge applied to the upper centres. The cathode on the spinal cord produces convulsions while the anode does not. The effects remain unchanged if the second electrode is removed from the spinal cord and applied to some spot outside the central nervous system. If, following extirpation of a small segment of the spinal cord, one electrode is placed on the head and the second electrode is applied to the cut surface of the lower part of the spinal cord, a perfect reversal of theScheminzky phenomenon can be obtained.TheScheminzky phenomenon is thus reduced to the well-known stimulating effect of the cathode and the paralysing effect of the anode. The question why a current passing in one direction (descending) should produce the anodic effect, while a current passing in the opposite direction (ascending) should produce the cathodic effect, can easily be explained by another well-known fact, i.e. the dependance of the lower spinal centres upon the higher ones. If the brain and upper centres are nearer to the anode (descending current), their anelectrotonic elimination has a paralysing effect, while their catelectrotonic excitation with an ascending current produces convulsions.     

Altersbedingte Abnahme von Kreatinphosphat und Änderungen der Adeninnukleotide in der Skelettmuskulatur von Ratten

Summary The content of phosphocreatine and of the adenin nucleotides, ATP, ADP and AMP in the white skeletal muscle of rats of different ages has been determined.There is an age-dependent relation between the quantity of phosphocreatine and the ratio of ATP/ADP. Young rats contain relatively much phosphocreatine (up to 57%) and a high ATP/ADP ratio (mean 6.7) while old rats show less phosphocreatine (40.8%) and also a low ATP/ADP ratio (mean 2.2).

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M. Ermini dankt der Schweizerischen Akademie der Medizinischen Wissenschaften für eine Verlängerung seines Stipendiums undI. Szelenyi dankt für ein USA Forschungs-Stipendium an das Institut für experimentelle Gerontologie in Basel. Herrn Prof.F. Verzár sind wir für die Leitung dieser und weiterer Arbeiten zu Dank verbunden.     

Metabolism of the neuromodulator d-serine

Over the past years, accumulating evidence has indicated that d-serine is the endogenous ligand for the glycine-modulatory binding site on the NR1 subunit of N-methyl-d-aspartate receptors in various brain areas. d-Serine is synthesized in glial cells and neurons by the pyridoxal-5′ phosphate-dependent enzyme serine racemase, and it is released upon activation of glutamate receptors. The cellular concentration of this novel messenger is regulated by both serine racemase isomerization and elimination reactions, as well as by its selective degradation catalyzed by the flavin adenine dinucleotide-containing flavoenzyme d-amino acid oxidase. Here, we present an overview of the current knowledge of the metabolism of d-serine in human brain at the molecular and cellular levels, with a specific emphasis on the brain localization and regulatory pathways of d-serine, serine racemase, and d-amino acid oxidase. Furthermore, we discuss how d-serine is involved with specific pathological conditions related to N-methyl-d-aspartate receptors over- or down-regulation.     

Gastric mucus effusion elicited by oral copper compounds: Potential anti-ulcer activity

Summary In rats, both Cu(I) and Cu(II) show an irritancy profile not shared with Cu^o or Zn(II) or Ni(II). The gastric response to Cu(II), i.e. copius fluid and mucus secretion, can protect the stomach from the acute ulcerative effects of aspirin or physical stress administered subsequently.to whom all enquiries should be addressed, Supported by grants from the National Health and Medical Research Council (Austr.) and University of Tasmania Research Commitee.Acknowledgments: ProfessorsW. R. Walker (Newcastle, Austr.) andL. Field (Nashville, Tenn.) for gifts of Cu(I) and Zn complexes;Dr. J. R. J. Sorenson (Cincinnatti, Ohio) for illuminating discussion; Drs.D. D. Perrin (Canberra) andR. P. Agarwal (Washington D. C.) for providing stability constants and much helpful advice.     

Untersuchungen über die alkylierende Wirkung von14C-Methylnitrosoharnstoff und 1-14C-Äthylnitrosoharnstoff

Summary Alkylation of RNA from brain, liver and kidney in rats after application of¹⁴C-methylnitrosourea and 1-¹⁴C-ethylnitrosourea was investigated. After administration of¹⁴C-methylnitrosourea the amount of 7-methylguanine in the RNA of brain and liver is about the same. Analogic experiments using 1-¹⁴C-ethylnitrosourea showed no alkylation of the RNA in the organs investigated. This leads to the conclusion that there is no direct correlation between the alkylation of RNA and organotropic carcinogenic activity of the compounds studied.

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Herrn Professor Dr.O. Eichler zum 70. Geburtstag gewidmet.     

The behavior of the homozygous and heterozygous sub-types of rats which are genetically-selected for diabetes insipidus: A comparison with Long Evans and Wistar stocks

Several aspects of spontaneous and conditioned behavior (food and water intake, locomotion and emotionality, passive and active avoidance acquisition and retention) of standard (albino and pigmented) rats, and rats heterozygous (HEDI) and homozygous (HODI) for diabetes insipidus, are reviewed. As would be expected, HODI rats have been repeatedly found to consume far more fluid than either HEDI or control rats. Pigmented rats appear to be more active than albinos. HODI rats exhibit less marked emotional responses than do control rats, among which the pigmented ones exhibit the highest emotionality. Light aversion is more evident in albino than in pigmented rats. No differences are found among HEDI, HODI and normal Long Evans rats. It is quite difficult to provide a clear-cut statement concerning inter-strain differences in passive avoidance behavior, possibly because of the variety of techniques employed. In any case, HODI rats do not perform worse than normal controls do. In one-way active avoidance paradigms, pigmented rats perform better than albinos, and the performance of HODI rats does not differ from that of controls. In two-way avoidance paradigms, albinos appear to outperform pigmented rats. Once again, there are no obvious differences between HODI and control animals.In addition to indicating that HODI rats may actually be less emotional than the other groups of rats reviewed here, the studies described once again fail to confirm the previously alleged functions of vasopressin in memory consolidation.     

High and low affinity transport ofL-arginine in rat brain synaptosomes

The uptake ofL-arginine into purified rat brain synaptosomes was investigated with respect to time and various concentrations ofL-[³H] arginine. Specific uptake was found to be linear with time for up to 5 min of incubation at 37°C. Electrolytes, including sodium chloride, potassium chloride, magnesium chloride and calcium chloride, inhibited uptake of 3 ML-arginine, and the inhibitory effect increased with increased electrolyte concentration under constant osmolarity. It was found thatL-arginine was transported into synaptosomes by two uptake components — a high affinity component (3.5 M) and a low affinity component (100 M). These two components were similar to the Ly⁺ system because of their extreme sensitivity to inhibition byL-lysine andL-ornithine but were distinguishable from each other by kinetic analysis of the uptake data and by their relative sensitivity to inhibition by several amino acids.     

The behavior of the homozygous and heterozygous sub-types of rats which are genetically-selected for diabetes insipidus: a comparison with Long Evans and Wistar stocks

Several aspects of spontaneous and conditioned behavior (food and water intake, locomotion and emotionality, passive and active avoidance acquisition and retention) of standard (albino and pigmented) rats, and rats heterozygous (HEDI) and homozygous (HODI) for diabetes insipidus, are reviewed. As would be expected, HODI rats have been repeatedly found to consume far more fluid than either HEDI or control rats. Pigmented rats appear to be more active than albinos. HODI rats exhibit less marked emotional responses than do control rats, among which the pigmented ones exhibit the highest emotionality. Light aversion is more evident in albino than in pigmented rats. No differences are found among HEDI, HODI and normal Long Evans rats. It is quite difficult to provide a clear-cut statement concerning inter-strain differences in passive avoidance behavior, possibly because of the variety of techniques employed. In any case, HODI rats do not perform worse than normal controls do. In one-way active avoidance paradigms, pigmented rats perform better than albinos, and the performance of HODI rats does not differ from that of controls. In two-way avoidance paradigms, albinos appear to outperform pigmented rats. Once again, there are no obvious differences between HODI and control animals. In addition to indicating that HODI rats may actually be less emotional than the other groups of rats reviewed here, the studies described once again fail to confirm the previously alleged functions of vasopressin in memory consolidation.     

Electrocardiographic and behavioral effects ofl-DOPA in the guinea-pig

Conclusions The effects ofl-DOPA administered per os on conditioning, spontaneous behavior and the electrocardiogram of the guinea-pig are reported and compared.l-DOPA is able to inhibit the conditioned behavior in doses per os without any effect on spontaneous behavior or motility. Moreoverl-DOPA in doses up to 15 times higher than the average therapeutic daily dose pro kg used in man (TDD), does not alter the ECG of the guinea-pig. We did not observe ECG changes even after a total dose pro kg 60 times higher than TDD, which induced behavioral alterations in the 4 treated animals and one death.The present results may indicate psychotropic properties forl-DOPA and do confirm the low toxicity and cardiotoxicity of the drug, when supplied in a pure preparation of quality 12.

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Zusammenfassung Verabreicht manl-Dopa (1000 mg/kg per os) an Meerschweinchen, so kann dadurch das konditionierte Verhalten gehemmt werden, während das Spontanverhalten und die Motilität unverändert bleiben. Es sind keine Modifikationen des Elektrokardiogramms festzustellen, selbst dann nicht, wenn die 60fache mittlere therapeutische Tagesdosis gegeben wird.