Effects of polysorbates and Cremophor EL on vascular responses in rat aorta

The effects of Tween 20, Tween 80, and Cremophor EL, surface active agents which are used for dispersion of water-insoluble substances, on vascular responsiveness were investigated using rat aortic rings. In high concentrations all these agents produced persistent contractions in aortic rings independent of the presence of endothelium. These contractions were not influenced by inhibitors of known endogenous contractile mediators. Incubation with these agents caused a concentration-dependent inhibition of the endothelium-dependent relaxant responses to acetylcholine in intact precontracted aortic rings. Endothelium-independent relaxations produced by sodium nitroprusside were not inhibited, but rather potentiated in the presence of Tween 80 (10^–1 ml/l). On the other hand, Tween 80 inhibited the contractile effects of 5-hydroxytryptamine, phenylephrine, and bradykinin significantly. The data suggests that these substances affect both endothelial cells and vascular smooth muscle.     

Membrane lipids and electron transfer. Effects of four detergents on NADH-ferricyanide reductase and NADH-cytochrome c reductase activities of potato tuber microsomes]

The NADH-ferricyanure reductase activity of Potato microsomes is stimulated by non ionic detergents (Triton X100 and Tween80) and is partially inhibited by ionic detergents (sodium-cholate and deoxycholate). All these four detergents progressively decreased the NADH-cytochrome c reductase in the following order: sodium deoxycholate greater than Triton X100 greater than sodium cholate greater than Tween80.     

Effect of Tween 80 on lipids ofMycobacterium phlei ATCC 354

Summary Addition of Tween 80 to the growth medium brings about qualitative and quantitative changes in the lipids ofMycobacterium phlei ATCC 354. The results suggest that Tween 80 itself may be a variant in the system.Acknowledgments. K. R. D. is grateful to the Indian Council of Agricultural Research, New Delhi, for the award of Senior Research Fellowship. This study was supported in part by funds from Indian Council of Medical Research, New Delhi, and University Grants Commision, New Delhi.     

The effect of lipase activity on the fat content ofStaphylococcus aureus

Résumé Deux souches deStaphylococcus aureus, l'un positif pour Tween 80 et l'autre négatif pour Tween 80 ont la propriété de décomposer des substrates lipidiques. Tous deux peuvent libérer des esthers d'acides gras contenant 16 atomes de carbone (longs et courts). Après l'action duStaphylococcus aureus positif pour Tween 80, des esthers contenant des longs acides gras sont aussi libérés. Dans ces conditions, la quantité totale de lipide bactérien devient plus élevée. Ces deux staphyloques incorporent de la même manière les acides gras libérés.     

A rapid method for measuring the phospholipid synthetic activity of incubated lymphocytes

Summary A rapid and simple method for estimating the phospholipid synthetic activity of incubated lymphocytes by a Florisil column technique following the uptake of¹⁴C-oleic acid was established. Stimulation of phospholipid synthesis by PHA and inhibitions caused by Tween 20 or Tween 80 and heating were evaluated easily with this method.     

The effects of 4 detergents on the respiration of mitochondria isolated from rat liver]

The effects of these four detergents (two non-ionic: Titron X100 and Tween 80, two ionic: sodium cholate and sodium dedeoxycholate) upon the respiratory intensities of mitochondria and upon the ADP/0 and respiratory control ratios were observed. At low concentrations and in the absence of exogenous ADP, non ionic as well as ionic detergents provoked a threefold (or fourfold) increase of the respiratory intensities of mitochondria. At higher concentrations, the four detergents were inhibitory for mitochondrial oxidations in the order: Triton X 100 greater than DOC greater than cholate greater than Tween 80. At increasing doses, the four detergents progressively decreased the phosphorylating capacities of mitochondria.     

Effect of increasing concentrations of detergents on electron transfer in chloroplasts]

The effects of increasing concentrations of sodium cholate and deoxycholate, "Tween 80" and "Triton X 100" upon O2 evolution by intact or osmotically broken spinach chloroplasts were investigated polarographically. Except for cholate, low concentrations of any detergent increased considerably (up to four times) the rates of oxygen evolution by broken chloroplasts, without interrupting the electron flux between photosystem II and photosystem I.     

Enhancement of fibrinolysis and thrombolysis by polysorbate 80 (Tween 80®)

Zusammenfassung Polysorbate 80 (Tween 80®), eine polyhydroxyle, nicht-ionisierbare, oberflächenaktive Substanz, vermindert die Adsorption von Urokinase an Glas, erhöht deren fibrinolytische Aktivität in vitro und steigert ihre thrombolytische Wirkung in experimentell hervorgerufenen Thrombosen im Kaninchen.

---

---

This work was supported by GrantsNos. HE-05020 and HE-7804 from the National Institutes of Health, National Heart Institute. The address of Dr.Kwaan is now: Northwestern University, Department of Medicine, Chicago (Illinois, USA).     

Effects of tween 80 on the growth of the Ehrlich-Lettré ascites carcinoma

Zusammenfassung Der Einfluss von Tween 80 auf das Wachstum des Ehrlich-Lettré-Carcinoms war statistisch nicht zu sichern, wenn die Gewichtszunahme allein gemessen wurde. Individuelle Variation im Flüssigkeits- und Zellgehalt zeigten, dass oberflächenspannungsherabsetzende Substanzen das Carcinomwachstum durch Eigenschaftsänderung der Zellmembran beeinflussen können.

---

---

Supported by Grant No. CA 05172 of the National Cancer Institute, U.S.P.H.S.     

Effect of tween 80 on protein-tannic acid complex

Riassunto L'acido tannico a basse concentrazioni forma complessi solubili con il citocromo C e la metamioglobina, modificandone i relativi spettri di assorbimento nel visibile. Il Tween 80 aggiunto alle soluzioni contenenti i suddetti complessi determina la rottura del legame proteina-acido tannico e la ricomparsa dello spettro caratteristico delle proteine in esame.

---

---

This work was supported by a grant from the « Impresa Enzimologia » of the Italian Consiglio Nazionale delle Ricerche and by Grant No. FG-It-128 from the U.S. Department of Agriculture.     

Zur Austestung von Wachstumsinhibitoren für Tuberkelbazillenin vitro

Summary The addition of serum or Tween 80 to a synthetic culture medium for tubercle bacilli considerably reduces the inhibitory effect of various substances with the exception of streptomycin and promin, whose effect is less weakened, and which retain their tuberculostatic action to a considerable degree. The antagonistic effect of Tween 80 is still recognizable in small dilutions where its diffusion effect can no longer be observed.

---

---

Die Arbeit wurde durch einen Arbeitsbeschaffungskredit des Bundes ermöglicht, für dessen Gewährung wir auch an dieser Stelle danken.     

The role of vitamin E in preventing the hemolysis of kid and chick erythrocytes with Tween 20

Summary Erythrocytes of vitamin E-deficient kids and chicks were hemolyzed at concentrations of Tween 20 above 1%. In vivo or in vitro uptake of vitamin E by the erythrocytes, or the addition of dithiothreitol or 2-mercaptoethanol, prevented the hemolysis with Tween 20.     

Immunization of mice against transplantable tumor

Zusammenfassung Nach i.p. Injektionen von mit Tween 80 behandelten Ehrlich-Lettré Ascites Krebszellen immunisierten Mäusen ergab sich bei diesen eine Widerstandsfähigkeit gegenüber Transplantaten von lebensfähigen Tumorzellen, woraus geschlossen wird, dass diese Behandlung die spezifischen Antigene der Zelloberfläche freisetzt.

---

---

The research was supported by a grant from the Medical Research Council of Canada. I wish to thank Mrs.I. Gower for valuable technical assistance.     

Protective effects of vitamin E and dithiothreitol against the hemolysis of rat and goat erythrocytes induced by Tween 20 with or without ascorbic acid and azide

Summary Exrtensive in vitro hemolysis of erythrocytes, induced in vitamie E-deficient rats by 0.001% Tween 20 with ascorbic acid and azide, or in goats by 2.5% Tween 20, could be counteracted by either the inclusion of vitamin E in the cells or by the in vitro addition of 0.25–0.4 mM dithiothreitol.     

Vitamin E,catalase, manganous or cobaltous ions and dithiothreitol protect against Tween 20-induced hemolysis of vitamin E-deficient chick and kid erythrocytes

Summary The effective Tween 20 concentration at which 70% hemolysis was achieved in vitro correlated with the plasma vitamin E content of chicks (r=0.85). Addition of catalase, MnCl₂, CoCl₂ or dithiothreitol in vitro showed significant protection against the hemolysis induced by Tween 20 in vitamin E-deficient chick and kid erythrocytes.     

Lipase activity in insect flight muscle

Zusammenfassung Die Lipaseaktivität von wässerigen Extrakten der Libelle (Pentala flavescens), der Heuschrecke (Schistocerca gregaria) und der Hummel (Xylocopa sp.) wurde manometrisch festgestellt, unter Verwendung von Tributyrin als Substrat. Die höchste Lipaseaktivität wurde in der Libelle gefunden, die niedrigste in der Hummel. Der hohe Gehalt der Flugmuskulatur der Insekten an Lipase wird in Zusammenhang gebracht mit der Benutzung von Fett als Brennstoff bei dauernder Muskeltätigkeit. Die Lipaseaktivität in der Flugmuskulatur der Libelle und der Heuschrecke wird histochemisch nachgewiesen mit dem Verfahren nachGomori, unter Verwendung von «Tween 80» als Substrat.     

Antioxidant and prooxidant roles of copper in Tween 20-induced hemolysis of hamster and pig erythrocytes containing marginal vitamin E

The concentration-dependent effects of copper acting either as an antioxidant or as a prooxidant were examined in vitro using Tween 20-induced hemolysis. When cupric ion concentration was more than 10 M, free copper(II) acted as a prooxidant; both extensive hemolysis and production of unknown thiobarbituric acid-reactive substance occurred in hamster and pig erythrocytes irrespective of vitamin E status. However, when cupric ion concentration was 2–4 M in the incubation medium, copper showed a clear antioxidant activity, reducing both hemolysis and malondialdehyde production induced either by diluted peroxide-containing Tween 20 with ascorbic acid and sodium azide in vitamin E-deficient hamster erythrocytes, or by peroxide-containing Tween 20 in pig erythrocytes containing marginal amounts of vitamin E. Copper(II) is taken up by the erythrocytes, where copper(I)-complexes may contribute to the protection of cells with membrane vitamin E against oxidative radical attack.     

Lipoxygenase activity of wheat seeding chloroplasts]

Chloroplasts have been isolated from Wheat shoots by density gradient centrifugation. When added to a linoleic acid and Tween 20 suspension these chloroplasts induce an oxygen consumption. The hydroperoxides synthesized from linoleic and oxygen have been characterized by spectrophotometry and thin layer chromatography.     

Glycoprotein biosynthesis in splenic cells. Purification of a microsomal galactosyl-transferase.

One part of the microsomal galactosyl-transferase activity of splenic cells of rats can by solubilized by the action of Triton X-100 and Tween 20. Its purification on a Sephadex G-200 column and by electrophoresis on a polyacrylamide gel leads to a solution of high specific enzymic activity.     

Comparative microelectrophoresis of different sera on nitrocellulose membranes impregnated with Tween 60

Zusammenfassung Durch mikroelektrophoretische Trennungen von Serumproteinen verschiedener Tierarten wurden weitere Anwendungsmöglichkeiten der Methode an mit Tween 60 (Polyglykolsorbitolmonostearat) imprägnierten Nitrocellulose Membranen geprüft. Die verwendete einfache Mikrotechnik erwies sich als besonders geeignet, charakteristische Unterschiede der Seren zu erfassen