Die α-Glycerophosphat-Oxydation des Heuschreckenbrustmuskels (Locusta migratoria)

Summary The conditions were studied for the glycerophosphate oxidation by homogenate from locust flight muscle, and the O₂-consumption was measured. Maximal oxidation rates were found with 0.087m glycerophosphate, 8 × 10^–6 m cytochromec, 7 × 10^–6 m DPN and pH 7.5. The production of dihydroxyacetone phosphate is followed by further oxidation steps, as could be shown by estimation of the different fractions of acid-soluble phosphate. Comparative studies were made on different insects and vertebrates. The rate of succinate oxidation by insect muscle was found to be ten times higher than that of vertebrate muscle. The relation of glycerophosphate oxidation to succinate oxidation is quite different in insects and vertebrates, but no difference could be detected between the two types of muscle metabolism of insects: the carbohydrate and the fatutilizing type.

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Mit Unterstützung der Deutschen Forschungsgemeinschaft.     

Modulation of carcinoembryonic antigen release by HT-29 colon carcinoma line in the presence of different agents

Summary In this study we followed the effects of various differentiating agents on the expression of carcinoembryonic antigen (CEA) released into the medium by a colon carcinoma cell line HT-29. Butyric acid 1 mM markedly increased the level of CEA (12-fold in comparison to control levels). 12-O-tetradecanoyl-phorbol-13-acetate (TPA) 50 ng/ml and 5-azacytidine 4×10^–6M increased the amount of CEA, 2- and 1.5-fold respectively. On the other hand retinoic acid 10^–5M, N methyl-formamide 1% and N,N hexamethylene bisacetamide 2.5 mM decreased CEA 2-, 4- and 3-fold respectively. Our results emphasize that various differentiating agents affect CEA levels differently. Thus changes in CEA levels appear not to be reliable as a marker of a more differentiated phenotype.     

Adenosine uptake in pyrimidine 5′-nucleotidase deficient human erythrocytes via a high affinity transport system

Summary Using a pulse-labeling technique,¹⁴C-adenosine uptake into pyrimidine 5-nucleotidase (P5N) deficient erythrocytes (RBC) was found to be impaired. The Lineweaver-Burk plot showed K_m values of 2.0×10^–3 mM and 0.2 ×10^–3 mM for normal RBC and P5N deficient RBC, respectively. These results indicate that P5N is one of regulators of the adenosine transport system and/or is associated with adenosine carrier protein.     

Parameters affecting the maximum cell concentration ofTetrahymena

Summary In cultures with efficient aeration a maximum cell concentration (MCC) of 6×10⁵ cells/ml (defined medium) and 5.5×10⁶ cells/ml (broth) can be reached. By culturing within Millicells with excess supply of medium and efficient removal of waste products a physical limit for MCC of about 13×10⁶ cells/ml is reached.     

VIP and histamine H2 receptor activity in human fetal gastric glands

Summary Vasoactive intestinal peptide (VIP, EC₅₀=6.4×10^–10 M) and histamine (EC₅₀=3×10^–6 M) activated the cyclic AMP generating system in gastric glands isolated from two human fetuses at 23 weeks gestation. Histamine antagonism by the H₂ receptor blockers cimetidine (Ki=0.35×10^–6 M) and ranitidine (ki=0.51×10^–7 M) clearly characterized the histaminic activation as being of the H₂ type. It is suggested that these two vasoactive hormones may operate as neurocrine/paracrine regulators of the differentiation and/or function of the human gastric mucosa in utero.     

A histochemical demonstration of the Na++K+-ATPase activity in the thyroid and the effect of cyclic adenosine monophosphate (c-AMP)

Summary With a suitable modification of the Farquhar and Palade technique the Na⁺+K⁺-ATPase activity in guineapig thyroid is demonstrated. The addition of c-AMP (5×10^–6 M or 1.5×10^–5 M) to the incubation media produced an apparent intensification of the Na⁺+K⁺-ATPase activity in the thyroid.This work was supported by a grant from ZMNU of Serbia.     

Age and evolution of bacteria

Summary Age and evolution of bacteria can be estimated, including facts and hypotheses belonging to morphology, biochemistry, paleontology, ecology and pathogenicity. The corresponding dates are summarized in the following.About 3.5×10⁹ years: Origin of heterotrophic eobiontes.—About 3.0×10⁹ years: The increasing lack of prebiogenic substances is due to the evolution of the respiratory pathway, that is due to the evolution of the photoautotrophy and now released O₂ is due to the evolution of strictly aerobic cells. There is, simultaneously, a transition of spheres to long forms, development of an amoebalike motility, the evolution of spirochetes and the substitution of cholesterol for cardiolipin in the more evolved cells (i.e. strictly aerobic cells etc.).—About 2.0×1.0×10⁹ years: Evolution of the eucyte by symbiosis of a great, primitive, anaerobic, cholesterol-containing cell with a little, strictly aerobic, cardiolipin-containing cell, with a spirochete and in some extent also with photoautotrophic cell.—About 1.0×10⁹ years (maximum: 1.8–1.5×10⁹ years, minimum: 7×10⁸ years): Evolution of metazoa and begin of cell differentiation.—About 2.0–1.0×10⁹ years: Evolution of the bacterial murein sacculus and then development of flagella mediated motility.—About 6×10⁸ years (maximum:1.0×10⁹ years, minimum: 4.5×10⁸ years): Evolution of the gram-negative cell wall.—About 4.0×10⁸ years: Evolution of the gram-positive cell wall.—About 5.0×10⁸ years: Gram-negative, strictly anaerobic bacteria become the first enteric bacteria in coelenterates. About 4.0×10⁸ years: gram-negative, microaerophilic bacteria become Enterobacteriaceae in vertebrates in addition to the strictly anaerobic organisms.—About 3.0–2.0×10⁸ years: Consolidation of the Salmonella in reptiles.—About 2.0–1.5×10⁸ years: Consolidation of Escherichia and other coliform species in mammals.—About 10⁶ years: Evolution of typically human pathogenic organisms, transmitted in homogeneous-homonomous infection ways, i.e. N. gonorrhoeae, S. typhi, T. pallidum, etc.Dedicated to Prof. H. Habs, Bonn, to his 75th anniversary on 11 September 1977.Acknowledgment. I thank Prof. F. Müller, Hamburg, and Prof. P. Sitte, Freiburg i. Br., for stimulating discussions.     

Lack of effect of dihydroergotamine on endothelial and smooth muscle cell proliferation and endothelial cell prostanoid production

Summary The most important effect of dihydroergotamine is venoconstriction, but certain metabolic effects and changes in vessel prostanoid activity have also been suggested. In this study endothelial cell production of 6-keto PGF₁ and TxB₂ was quantitated in vitro. No evidence of altered prostanoid production was noted after incubation with dihydroergotamine (exposure ranging from 5×10^–3 to 5×10^–7 g/l). Similarly, no effect of dihydroergotamine on the growth rates of endothelial cells or smooth muscle cells in vitro was documented.     

Net ATP synthesis by running the red cell calcium pump backwards

Summary Ca²⁺ loaded inside-out vesicles from human red blood cells, yielding Ca²⁺ into a Ca²⁺ free medium with 4 mM EGTA, 2 mM ADP and 10 mM phosphate, produced an excess of 14.9 pmoles · min^–1 · (mg protein)^–1 of ATP compared to controls in which the transmembrane Ca²⁺ gradient was abolished by the ionophore A 23 187.We are obliged to Dr H. Fey and Miss H. Pfister (Veterinarybacteriological Institute Bern) and Dr H. Porzig (Pharmacological Institute Bern) for help and advice.     

Drug interactions in intestinal absorption of3H-digitoxin in rats

Summary The absorption of³H-digitoxin from perfused rat small intestine was inhibited by probenecid (1.0×10^–2 M), ethacrynic acid (0.5×10^–3 M), and mersalyl (8.0×10^–3 M) indicating that digitoxin absorption is at least partly an active process.     

The uptake of iodinated protein by spleen cells of guinea-pigs in vitro

Zusammenfassung 6×10^–10 g bis 10^–4 g J 125 Rinderserum-Albumin (BSA) bzw. 1,0×10^–7 bis 1,0×10^–6 g J 125 Rinderserum--Globulin (BGG) werden 3 × 10⁷ Milzzellen normaler Meerschweinchen in vitro angeboten. Unabhängig von der Höhe des Angebotes beträgt die Menge des aufgenommenen BSA 1%, die des aufgenommenen BGG 10% des Angebotes. Durch 4C Inkubations-temperatur wird die Aufnahme z.T. behindert. Die Aufnahme findet nach wenigen Sekunden Inkubationszeit statt und ist nach etwa 2–3 min abgeschlossen.

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The work was supported by a grant of the Stiftung Volkswagenwerk and of the Deutsche Forschungsgemeinschaft.     

Caclium causes the biphasic dose-response curve for pancreatic amylase secretion

Summary High concentrations of bethanechol (10^–4 to 10^–3 M) were effective stimulants of amylase secretion from the mouse pancreas if incubations are performed in low [ca²⁺] (0.1 mM) solutions but not if normal Krebs solution (2.56 mM Ca²⁺) was used. This inhibitory effect of Ca²⁺ at high secretagogue concentrations did not appear to be mediated through the microtubules or microfilaments.     

Inhibition sélective des «vraies» et «pseudo»-cholinestérases du rectus de grenouille

Summary The hydrolysis of acetylcholine chloride (0.01M) by frog's rectus extracts, is inhibited by low concentrations of 3318 CT (CI-50 3.2×10^–7) and high concentrations of D.F.P. (CI-50 1.3×10^–5). Inversely, the hydrolysis of butyrylcholine perchlorate is inhibited by low concentrations of D.F.P. (CI-50 3×10^–9) and high concentrations of 3318 CT (CI-50 3×10^–4). Both are inhibited by similar concentrations of neostigmine (CI-50 1.1×10^–7 and 1.5×10^–7). Frog's rectus thus contains true and pseudo-cholinesterases. The inhibitions produced by D.F.P. added to the muscle itself (and not the extract) correlates well with the potentiation of the corresponding ester. Sensitization to AcCh and to BuCh appears to be specifically related to the inhibition of Ac ChE for the former ester, of XChE for the second one.     

Role of calcium in the histamine release induced by D-galactosamine from rat mast cells

Summary Rat peritoneal mast cells were isolated and purified by differential centrifugation in Ficoll. Cells pooled from three to four rats were suspended at approximately 10⁶ cells/ml in a buffered salt solution and incubated for 1 h at 37°C in 300 l volumes in the absence or presence (9×10^–4 M) of calcium chloride. Addition of D-galactosamine hydrochloride (DGM; 2.8×10^–4 M) caused (in addition to basal release) a mean ±SEM percent histamine release of 15.7±5.2 in the presence of Ca⁺⁺ and 19±4.9 in the absence of Ca⁺⁺ (p>0.05). It is suggested that D-galactosamine does not require extracellular Ca⁺⁺ for the release of histamine from the rat mast cell.A preliminary analysis of these results was presented at the International Symposium on calcium entry blockers and tissue protection, Rome, 15–16 March 1984.     

Effect of NPV of the armywormMythimna (Pseudaletia) separata on the silkwormBombyx mori

Summary Nuclear polyhedrosis virus (NPV) material of the armywormMythimna (Pseudaletia) separata was administered in the form of PIBs and free virus rods to the larvae of silkwormBombyx mori. Routes used for administration were topical, intrahaemocoelic and oral. The larvae were treated with following concentrations: 10×10⁵ PIBs/L, 10×10⁶ PIBs/L, 10×10⁷ PIBs/L, 10×10⁸ PIBs/L. In all the 3 experiments, the larvae showed neither any signs and symptoms, nor mortality due to polyhedrosis. Thus it appears that the NPV ofM. (P.) separata is safe for the silkwormB. mori.Acknowledgments. We are grateful to the Karnatak University, Dharwad, for awarding UGC Junior Fellowship to S.G.D. and for financial assistance made available to S.B.M. We thank Professor M. Appaswamy Rao, Department of Zoology, for providing the necessary facilities. Our thanks are also due to Mr B. Chavannawar for supplying mulberry leaves and to the Government Silk Farm, Hindalaga, Belgaum, for providing silkworm eggs.     

Inhibition of Mn++-catalyzed autoxidation of adrenaline by ascorbic acid

Zusammenfassung Die Autoxydation von Adrenalin in Anwesenheit von Mn⁺⁺ wurde quantitativ untersucht. Es ergab sich, dass die durch 0,1 mM Mn⁺⁺ bewirkte vollständige Oxidation von Adrenalin durch 5 × 10^–5 g/ml Ascorbinsäure verhindert werden konnte.     

Catecholamines in bovine semen

Summary In seminal plasma 5×10^–6 M noradrenaline was found to induced head-to-head association in bull spermatozoa. The sum of noradrenaline and adrenaline in freshly collected semen was 10 ng/ml (5.2×10^–8M), i.e., about 100 times lower than previously reported.     

Growth stimulating effects of the bromophenol,lanosol, on red algae in axenic culture

Zusammenfassung Wachstumstimulation von 2,3-Dibromo-4,5-Dihydroxybenzylalkohol (Lanosol) in Konzentrationen von 4×10^–5–4×10^–6 wurde in axenischen Kulturen der RotalgenGoniotrichum alsidii undPolysiphonia urceolata festgestellt. Während das Disulfatdikaliumsalz nicht toxisch und von niedrigerer Aktivität war, hatte 2×10^–4 M Lanosol eine Hemmwirkung aufPolysiphonia.     

Effect of enkephalins in the presence of the antibiotic bacitracin in the longitudinal muscle strip preparation from guinea-pig ileum

Summary The antibiotic bacitracin (5×10^–5–4×10^–4 M) increases the inhibition of the contractile response caused by both enkephalin release and direct application of Met-enkephalin 5×10^–7 M in the longitudinal muscle strip preparation from guinea-pig ileum. This effect is attributed to an inhibition of enkephalin degrading peptidases by bacitracin.     

Bactericidal activity againstPseudomonas aeruginosa is acquired by cultured human monocyte-derived macrophages after uptake of myeloperoxidase

Myeloperoxidase (MPO) is an enzyme located within polymorphonuclear neutrophils capable of producting cytotoxic oxidant species that are particularly active against bacteria with polysaccharide capsules.Pseudomonas aeruginosa (10⁶ bacteria per 1 ml) are killed within 1 h in vitro by a MPO/H₂O₂/Cl^– system (48 mU=132 ng of MPO). The question arose as to whether human macrophages would acquire cytotoxic activity when loaded with this enzyme. Monocytes were therefore isolated from human blood and cultured for up to ten days to induce maturation to macrophages. These cells lost endogenous MPO within five days while H₂O₂ production in response to stimulation by phorbol myristate acetate (10^–6M) decreased to 23% within ten days. On the other hand, their capacity to take up exogenous MPO increased fourfold from day three to day ten. Human macrophages cultured from eight days (when both H₂O₂ production and MPO uptake were sufficient) were therefore used to study the effects of MPO uptake on cytocidal activity againstPseudomonas aeruginosa. After a 1 h MPO loading period, macrophages (5×10⁵ cells per ml) were incubated in the presence of bacteria (0.5 to 2×10⁶ bacteria per ml) for 2 h at 37°C. At a bacteria/macrophage ratio of 1, only 34.8±7.0% of bacteria survived (compared to killing by non-loaded macrophages), while 74.4±9.3% survived at a ratio of 4. From these results, we conclude that loading macrophages with exogenous MPO could enhance their microbicidal activity, suggesting a potentially useful therapeutic application.