Der erythrocytäre Magnesiumstoffwechsel bei intakter und kälteinhibierter Glykolyse

Summary Continuation of glycolysis in human erythrocytes by incubation of heparinized whole blood at 37°C is followed by a decrease in the Mg-content of red cells. On inhibition of glycolysis by cold (4°C), the Mg-content of erythrocytes remains unaltered or, often, slightly increases. These actions are in clear contrast to the behaviour of potassium ions under the same conditions.     

Increased erythrocyte permeability to Li and Na in the spontaneously hypertensive rat

Summary Red blood cells incubated in a physiological medium in which Li replaces Na (LiPSS) gain Li in exchange for Na and K. The rate of Li uptake is modestly but significantly increased in the spontaneously hypertensie rat (SHR) at 37°C and at 22°C. The slow rate of Na gain and K loss during cooling at 2°C was about doubled in unmodified whole blood samples from the SHR.This work was carried out with the aid of a grant from the British Columbia Heart Foundation.     

Ein Beitrag zur irreversiblen Temperaturinaktivierung der Gewebsatmung

Summary (1) Tissue slices of the liver and pieces of the skin of summer-frogs were incubated at 47.5°C for 30–150 min. Their respiration was measured during this incubation period and thereafter at a temperature of 37.5°C.(2) As a sign of an irreversible inactivation of the enzymes, the average respiration was inhibited. However, after certain periods of incubation at 47.5°C, over-shoot phenomena in the O₂-uptake at the temperature of 37.5°C were seen.     

The generation of toxic activity fromTrypanosoma congolense

Summary Trypanosoma congolense organisms, on incubation at 20°C for 91/2h, were found to generate phospholipaselike activity which was capable of mediating lysis of both nucleated cells and erythrocytes as well as an acute inflammatory response on intradermal inoculation.Acknowledgments. This investigation was supported by the International Development Research Centre.     

Einfluss von angiotensin auf das argentaffine system des meerschweinchens

Summary The duodenum of guinea-pigs were dissected immediately after death and incubated for 10 min at 37 °C in a solution of Krebs-Ringer-Bicarbonate buffer, in which Hypertensin (CIBA) was added. The result was that the argentaffine cells were more numerous after the incubation period, as compared with the controls. The 2 controls were pieces placed into the solutions of Formalin and blank Krebs-Ringer-Bicarbonate buffer.     

Kalium-Austausch zwischen Plasma und Erythrozyten beim Karzinom

Summary The erythrocytes of mice inoculated with Ehrlich-ascites-tumor growing in the solid form interchange their potassium ions with those of the plasma at a more rapid rate than the erythrocytes of controls. This difference is also observed when the erythrocytes of tumor mice are incubated in normal plasma.When normal erythrocytes are incubated in plasma of tumor mice, an accelerated potassium interchange is also observed.

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Der Dank des Verfassers gilt Herrn Prof.G. v. Hevesy für sein förderndes Interesse und der Riksföreningen mot caucer für die Unterstützung dieser Untersuchungen.     

Effect of temperature on in vitro proliferative activity of human umbilical vein endothelial cells

Human umbilical vein endothelial cells, skin fibroblasts, and retinal pigment epithelial cells are cultivated in medium supplemented with 15 to 20% serum in our laboratory. The effects of various incubation temperatures on the proliferation of these cells was examined. Our study shows that the mitogenic response of the endothelial cells to a change of temperature differed markedly from that of the fibroblasts and epithelial cells. Cultivation of human umbilical vein endothelial at 37°C required seeding densities as high as 1–2×10⁴ cells/cm², and yet resulted in a low growth rate and premature senescence. However, under the same culture conditions, but at 33°C, the proliferative capacity of these endothelial cells was potentiated. The results were striking; at 33°C the cells grew actively and the life span was extended. The number of cumulative population doublings increased fourfold compared with that for the same cells cultivated at 37°C. The inoculum size could be reduced, since at 33°C the endothelial cells were able to replicate at seeding densities as low as 20 cells/cm². The cells serially subcultured at 33°C retained morphological features and specific immunological markers of endothelial cells.     

Amin-transport hypothalamischer Vesikel

Summary Noradrenaline storing vesicles were isolated from the pig hypothalamus and incubated at 0° and 37 °C. In the presence of ATP the uptake of noradrenaline is activated by Mg⁺⁺ but not by Ca⁺⁺. At 37 °C the passive transport of noradrenaline is practically accomplished within 1 min, the active one within 6 min.

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Ausgeführt mit Unterstützung der Deutschen Forschungsgemeinschaft.     

Die Wirkung von Desoxycorticosteron auf den aktiven Kationenaustausch an Rattenblutzellen

Summary Cold-stored blood cells of rats, which were depleted of potassium and had gained an equivalent amount of sodium instead, were incubated with 500 mg% glucose at 37°C in serum. Under these conditions an extrusion of sodium from and a re-entry of potassium into the cells could be observed. Desoxycorticosterone, when added in a concentration of 1 mg per ml, was able to slow down the rate of this exchange to three fifths of the rate of untreated cells. With blood of adrenalectomised rats, the same effect of DOC was observed, although the rate without DOC was somewhat lower than in the blood of normal animals. There was no statistically significant difference between the DOC-effect in blood of normal and adrenalectomised rats.     

A new cell line (XTY) from a tumor ofXenopus laevis

A new cell line (XTY) was derived from a tumor of a femaleXenopus laevis. This cell line has been proliferating in standard amphibian culture medium for more than 4 years (470 generations) and has a doubling time of 75.5 h at 25°C. The cells aggregate into large groups, and their stellate morphology and the expression of desmin demonstrated by immunocytochemistry suggest that their origin is not epithelial.     

Hemoglobin binding capacity of heat incubated sera of different haptoglobin subtypes

Summary Sera of haptoglobin subtypes Hp 1F-1F and Hp 1S-1S incubated at 56°C show a different degree of reduction in the hemoglobin binding capacity. The difference is small but significant.     

Glycerin prevents the ‘heat-death’ of ehrlich ascites tumor cells

Summary When heated to 45°C for 20 min Ehrlich ascites tumor and NK-lymphoma cells are irreversibly damaged, so that they lose transplantability. The presence of 7–8% glycerol during heat treatment protects EAT cells completely and NK-lymphoma cells partly against this injury.     

Die Hämagglutination des Influenzavirus A2-Hongkong

Summary A₂-Hongkong influenza virus does not agglutinate the erythrocytes of the cow, the calf, the horse, the pony and the spiny mouse at room temperature, while the A₂-Asia influenza virus causes agglutination. At a temperature of 4 °C A₂-Hongkong was able to agglutinate the erythrocytes of all species examined except those of the spiny mouse. Whether the A₂-Hongkong virus does or does not agglutinate the erythrocytes of the chicken, the donkey, the goat, the spiny mouse and the horse at room temperature could depend on the speed of elution.     

Noradrenalin-Freisetzung aus dem Hypothalamus in vitro

Summary Rat hypothalami were isolated and incubated at 37 °C in Ringer solution. Both calcium and acetylcholine enhance the release of noradrenaline. The effect of acetylcholine is dependent on the presence of calcium ions.

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Durchgeführt mit. Unterstützung der Deutschen Forschungsgemeinschaft.     

Chronic sensory denervation reduces thrombin-stimulated endothelin release from aortic endothelial cells

The long-term (trophic) influence of perivascular nerves on the endothelium was investigated by measuring changes in thrombin-stimulated release of the potent vasoconstrictor, endothelin, after selective chronic denervation. Rat pups were treated with either guanethidine or capsaicin to destroy sympathetic or sensory nerves, respectively. The abdominal aortas from the rats at three months of age (5 pooled per experiment) were incubated with 4U thrombin/ml in medium for 24 h at 37°C, and the amount of endothelin released from the preparation determined by immunoassay. After neonatal sensory denervation there was a significant reduction in the thrombinstimulated release of endothelin compared to the controls (0.012±0.012 (4) compared to 0.063±0.012 (6), pmol/cm²/24 h, p<0.02). There was no change in endothelin release after sympathetic denervation. In summary, sensory nerves play a trophic role in the expression of endothelin in endothelial cells of the intima.     

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.     

Periodate oxidation of lymphocyte membrane glycoconjugates]

Mouse spleen cells free of erythrocytes were suspended in PBS at a concentration of 2 X 10(7) cells/ml and mixed with an equal volume of sodium periodate in PBS for 10 min. at 4 degrees C to give a final concentration of periodate ranging from 10(-4) M to 5 X 10(-3) M. The cells were then washed and suspended (60 X 10(6) ml) in PBS containing 3H-labelled sodium borohydrate and incubated for 30 min, at 23 degrees C. Following this, the cells were washed and the pellets treated with H2SO4 0.1 N for 60 min. at 80 degrees C. Compounds liberated by such treatment, were identified by chromatography as derivates of sialic acid. The data provide direct evidence that the mitogenic effect of sodium periodate is associated to the oxidation of the sialic acid residues on the lymphocyte membrane.     

Photoperiod-induced changes in temperature-metabolism curve,shivering threshold and body temperature in the pigeon

Summary A short photphase combined with cold-acclimation changed the shivering threshold of the pigeon from 21 to 14 °C. The change of critical temperature was also found in the temperature-metabolism curve. A long photophase both alone and combined with warm-acclimation induced a reduction of body temperature to a lower level (about 2°C) at all ambient temperatures, ranging from 5 40°C.     

Persistence of added retinoids in organ culture media during induction of mucous metaplasia and glandular morphogenesis in hamster cheek pouches

Summary The retinoid concentration (determined colorimetrically) did not change significantly in retinyl acetatesupplemented (6 g/ml) Eagle's Minimal Essential Medium containing 10% fetal calf serum when stored at –20 or 4°C over 7 days. After the medium was incubated at 37°C for 48 h, 37–49% of the retinoid remained, whether or not tissue (neonatal Syrian hamster cheek pouch) was present, and irrespective of explant age. The normal retinoid level in the tissue was approximately 0.25 g per gram. Therefore, neonatal hamster cheek pouches, incubated in medium with the addition of 6 g of retinyl acetate per ml of medium and undergoing mucous metaplasia and some mucous gland morphogenesis, were continually being exposed to retinoid levels which, though gradually decreasing, remained well above their normal physiological level.     

The growth of Atlantic salmon (Salmo salar L.) myosatellite cells in culture at two different temperatures

Temperature is known to affect fish growth, and in Atlantic salmon there is an influence on muscle cellularity. Primary muscle cell culture makes it possible to investigate direct effects of temperature on myogenic cells. Salmon myosatellite cells were cultured for the first time in this study. The cells were cultured at either 5°C or 11°C. Increased temperature led to an increase in differentiation rate and especially hypertrophic growth (Q₁₀=4.0). No nuclear proliferation was evident in the satellite cell population isolated at either temperature. This may be due to the presence of different subpopulations of myogenic cells at different developmental ages or the presence of indirect factors in vivo.