Baroreceptor and sympathetic responses to acebutolol, a beta 1-adrenoceptor-blocking agent, in rabbits.

Baroreceptor activity was increased after i.v. infusion of acebutolol in rabbits with an intact circulation, and in rabbits with a total cardiopulmonary by-pass. In rabbits with an intact circulation, renal nerve activity was reduced.     

Adrenalectomy,ovarian HCG-binding and the onset of female puberty in the rat

Summary The delay of puberty onset in female rats adrenalectomized before the 25th day of age is due neither to changes in the number of ovarian HCG-receptors nor to an altered hormone affinity of these receptors. It is assumed that glucocorticoids act on an intracellular level, in the ovarian cells, possibly by alterations of cyclic AMP-dependent phosphodiesterase activity.This work was supported in part by the Deutsche Forschungsgemeinschaft (SFB 46). Purified HCG was a gift of Schering AG, Berlin-West. We thank Mrs Margarete Lindig for assistance and Mrs Ursula Frigewski for secretarial help.     

14-3-2 protein in rat brain synapses

Summary The distribution of the 14-3-2 protein in rat brain synapses was studied by immuno electron microscopy. The protein was localized to the postsynaptic web and to the postsynaptic membrane, but was also prominent both in the presynaptic membrane and in the presynaptic densities. No significant activity was observed in the synaptic vesicles.Acknowledgments. Our sincere thanks to Mrs Ulla Svedin, Eng., for skilled technical assistance. This work was supported by grants from the Swedish Medical Research Council, the Medical Faculty of Göteborg, Tore Nilson's Foundation for Medical Research and by the Swedish-Italian Group of Neurobiology. A. G. received financial support from Consiglio Nazionale delle Ricerche (CNR, ROME).     

Relation between stimulus intensity and neutrophil chemotactic response

Summary The effect of chemotactic peptides which lack chemokinetic activity has been investigated. The neutrophil response is proportional to the logarithm of the stimulus intensity, or alternatively a power function with an exponent of 0.3. Equal responses are obtained for equal ratios between the peptide concentration in the lower compartment and the threshold concentration. The significance of Weber-Fechner's law in leucocyte chemotaxis is discussed.We thank Miss B. Zanolari, Mrs M. Marti, Mrs Hauck and Mr Dietz for excellent technical assistance. This work was supported by the Swiss National Foundation for Scientific Research.     

Solubilization of human red cell membranes by lysolecithins of various chain lengths

Summary Red cells and membranes prepared from them were treated with graded amounts of palmitoyl, myristoyl and lauroyl lysolecithins. There was no release of phospholipids from the intact red cells in the absence of hemolysis. The solubilization pattern of lipid and protein from the red cell membranes by lysolecithins varies with their chain length.The skillful technical assistance of Mrs Isca Levy is gratefully acknowledged.     

Impaired proximal tubular transport functions in anaesthetized splanchnicotomized dogs

Summary The maximal tubular transport of inorganic phosphate,d-glucose and para-aminohippuric acid, respectively, was depressed on the denervated side in unilaterally splanchnicotomized, anaesthetized dogs. It is concluded that renal sympathetic activity might in general regulate proximal tubular transport functions.The authors are indebted to Mrs V. Vajda, Mr A. Karai, Mrs K. Kéry, Mrs B. Asztalos, Mr S. Szécsi and Mr J. Vártok for their valuable technical assistance.     

The importance of the terminal hemi-acetal group for the ionophoric properties of nigericin

Summary Opening of the terminal hemi-acetal in dihydronigericin drastically reduces the ionophoric properties of nigericin and dehydroxymethylnigericin with 6 intact heterocycles. This is shown by 2 complementary methods, first with a liquid membrane electrode system, secondly by testing their ionophoric activities in rat liver mitochondria.Acknowledgments. The authors are indebted to Mrs G. Kergomard for her invaluable assistance in the isolement of nigericin and to Prof. A. Kergomard for his encouragements.     

Adrenergic neuroplasticity is maintained in the nutritional rehabilitated adult rat

Summary This work examined the capacity of intact catecholaminergic axons to grow, in response to lesions, in the brain of adult rats following nutritional rehabilitation. The partially deafferented epithalamic habenula was used as a model to study neuronal plasticity. Noradrenergic neurons appear to maintain their plasticity in rats recovered from their postnatal undernutrition.Supported by a BRSG-UTMSH grant.Supported by a NIH grant.Acknowledgments. Thanks are due to Mrs Malka Gottesfeld for her invaluable assistance.     

Age-dependent change in the ability of protein synthesis,by rat liver microsomes-significance of 2 associated factors

Summary An activator and an inhibitor of polypeptide synthesis were isolated from microsomes of rat liver. The young rat contained a higher level of the activator but a lower level of the inhibitor than the aged rat. The significantly higher ratio of the specific activity of the activator to inhibitor in the young microsomes helps explain the higher capacity for protein synthesis of these microsomes as compared to the microsomes of the aged animal.The author thanks Mrs. M. Guillier for her technical help in this work.     

Antikörperproduktion mit isolierter Bakterienzellwand und mit Protoplasten

Summary The cell wall of an aerobic bacillus isolated with trypsin treatment produces in rabbits a polysaccharide antibody which is responsible for the majority of the serological reactions of the cell surface.After digestion of the cell wall polysaccharide with lysozym, intact, naked protoplasts can be obtained in isotonic saccharose solution. This produces in rabbits an antiserum which contains no polysaccharide antibody and which reacts not only with the protoplasts but also with a thermolabile protein of the bacterial surface.     

Failure of calcium to stimulate Na,K-ATPase in the presence of EDTA

Summary The effect of calcium on Na, K-ATPase activity of rat brain homogenates and its modification by the chelating agent EDTA has been investigated. In the absence of EDTA, free calcium (approximately 10^–6mol/l) stimulates Na,K-ATPase activity; in the presence of EDTA the same concentration of free calcium is without effect on the enzyme. In the absence of EDTA the stimulation by calcium of Na,-K-ATPase activity is enhanced by the additional presence of calmodulin but in the presence of EDTA, even when calmodulin is added to excess, calcium still fails to stimulate the enzyme. The possibility that EDTA interferes with an interaction between a calcium-calmodulin complex and Na,K-ATPase is discussed.The expert technical assistance of Mrs Paula Jarvie is gratefully acknowledged. Thanks are due also to Professor Philip Kuchel for assistance with the calculations to determine the concentrations of metal-ligand complexes in the experimental media.     

Effect of actinomycin D on the quail oocyte nucleolus during meiotic prophase I

Summary Actinomycine D alters profoundly the distribution of the nucleolar constituents in the quail oocyte at prophase I of meiosis. As a consequence of nucleolar segregation the normally existing relations between the nucleolus fibrillar centers and the microchromosomes are ruptured. The relations between the fibrillar center and the dense fibrills which surround it remain intact, suggesting that they constitute together a functional unit.With the technical assistance of Mrs A. Calisti.     

Demonstration of the presence of M-creatine kinase in mammalian myogenic cell lines

Summary Unequivocal identification of M-CK in cell extracts from fused cells of myogenic cell lines is difficult due to almost identical behaviour of the M-CK and a contaminating enzyme activity in electrophoresis. If CK dimers present in cell extracts were subjected to dissociation and reassociation in the presence of exogenous B-CK subunits, the formation of easily identifiable MB-CK was demonstrated, indicating the presence of M-CK in the myogenic rat cell lines.Acknowledgments. We are grateful to Mrs M. Siegrist and Dr D. Turner for communication of preliminary results and helpful discussions, Mrs E.R. Perriard for skillful technical help. Supported by a grant of the Muscular Dystrophy Association Inc. to H.M.E.     

Effect of ambient cold on urine concentration by the intact and denervated dog kidney

Summary In dogs transferred from room temperature to a low temperature of 1±(SD) 3.5°C, the plasma norepinephrine (NE) level increased significantly. Urine concentration decreased in the cold, in the intact and similarly in the chronically denervated kidney. After return to a warm environment urine concentration improved in both kidneys while plasma NE remained elevated. The data speak against an essential role of the renal nerves in the adaptation of renal function to ambient cold.Acknowledgments. We are greatly indebted to Dr J. Kurkus and Dr R. Gellert who performed the operations of surgical bladder division, and to Mrs W. Radziszewska for determination of plasma norepinephrine. The study was supported within the national research problem No. 10.4.     

Liver enzyme induction by the anion exchanger resin,Dowex 1×2, in the rat

Summary Peroral treatment of rats with the anion exchanger resin, Dowex 1×2, for 8 days leads to liver enlargement and increase of alkaline and acid phosphatases, glucose-6-phosphate dehydrogenase, malic enzyme, catalase, and the enzymes of microsomal drug metabolism in the liver. The sequestration of bile acids by this treatment mimics the biochemical effects of clofibrate- and phenobarbital-like drugs in the liver.Acknowledgment. The authors want to thank Mrs Fey, Mrs Kremer and Mr Weinrauch for their skilful technical assistance.     

Alterations ofβ-adrenoceptor-density and cAMP-synthesis in rat-erythrocytes after stress erythropoiesis

Summary During the maturation of red blood cells from rats after stress erythropoiesis, adenyl cyclase activity and -adrenoceptor density (pmoles/mg protein) decrease at distinctly different rates suggesting a different turnover of these membrane units.Acknowledgments. This work was supported by the Deutsche Forschungsgemeinschaft. The skillful technical assistance of Mrs I. Groth and Mrs C. Kiele is gratefully acknowledged. The liquid scintillation spectrometer was a gift from the Dr Robert-Pfleger-Stiftung.     

Potentiation of ocular response to adrenaline by 3,3-dimethyl-1-[3-methylaminopropyl]-1-phenylphthalan (Lu 3-010) and a thiophthalan analogue (Lu 5-003): Blockers of catecholamine uptake

Résumé Concernant la durée de l'effet du traitement, le composé Lu 3-010 en combinaison avec l'adrenaline est semblable à la protriptyline, et il est plus actif que Lu 5-003 en ce qui concerne la potentiation de la reaction oculaire provoquée par l'adrenaline. Administrés séparement, les composés Lu 3-010 et Lu 5-003 ont des effets semblables, tandis que la protriptyline est le composé le plus actif. L'accroissement de l'efficacité de ces composés résulte probablement de leur abilité à bloquer le mécanisme de l'incorporation de la catecholamine.

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The author acknowledges the technical assistance of Mrs.S. Schaal, Mrs.C. Wood, MissB. Kawchak and Mrs.B. Sumner. The Lu compounds were gifts from H. Lundbeck and Co. Ltd.     

Drug action on adenylate kinase activity in cerebrospinal fluid of arteriosclerotic patients

Summary A manifest presence of adenylate kinase activity in cerebrospinal fluid was found in patients with cerebral arteriosclerosis. This activity was significantly higher during treatment with co-dergocrine (Hydergin^®) compared with the two periods before and after treatment.Acknowledgment. We are obliged to Mrs M. Hedström, for skilful technical assistance. This study was supported by a grant from the Södermanland Country Council. The study plan was approved by the Ethical Committy of Medical Faculty at the University of Uppsala.     

Immunological blocking of exogenous and endogenous secretin in the dog

Summary In mongrel dogs with chronic gastric and duodenal fistula the biological activity of secretin on exocrine pancreatic secretion could be blocked by preincubating the secretin injected with rabbit antisecretin antibody. In addition, the activity of endogenous secretin released by acid was markedly reduced by application of antibody. Since no such effect was observed after testmeal stimulation, secretin is most probably not released in a significant amount by the liquid meal used in this experiment.This work was supported by grant No. 3.816-0.76 of the Swiss National Foundation for Scientific Research.We express our thanks to Miss G. van Hees, Mrs L. Jecker and Dr F. Meyer for their excellent technical assistance, Dr W. W. Rittmann for the surgical support, Dr G.A. Stalder for general advice, Dres R. Studer and D. Gillessen for providing secretin Roche, and Mrs C. Frei for secretarial work.     

Tolerance to,and symmetrical cross-tolerance between,cannabionol and 295-1295-1295-1

Summary Tolerance to, and symmetrical cross-tolerance between, cannabinol and ⁹-tetrahydrocannabinnol (THC) occurs in rabbits which uniquely exhibit behavioral convulsions with THC.This research was supported by funds (grant No.DA01448) and cannabinoids from the National Institute on Drug Abuse.