Influence of prostaglandins E1 and E2 on coagulation of rat blood

Zusammenfassung Die Prostaglandine E₁ (PGE₁) und E₂ (PGE₂) haben keinen Einfluss auf die Gerinnung von Rattenblut. Im Gegensatz zu früheren Postulationen können die Ca-Ionen im Plasma nicht von PGE₁ ersetzt werden. PGE₁ beeinflusst die maximale Amplitude des Thrombelastogramms in vitro nach Zugabe von 0.3–6 g/ml, während PGE₂ diesen Effekt nicht aufweist.     

Influence of ionizing radiation on protein production by HeLa cells in culture

Zusammenfassung Bei der Züchtung von HeLa-Krebszellen in tritiumhaltiger Nährlösung während 48 h wurde festgestellt, dass die Mitoserate durch viel kleinere Strahlendosen nachweisbar herabgesetzt wird als die radiochemisch gemessene Rate der Proteinsynthese.     

Inhibitory effect of cytembena (sodium-cis-beta-methoxybenzoyl-beta-bromoacrylate) on the cell kinetics of HeLa cells in culture

The inhibiting effect of Cytembena on HeLa cell kinetics has been demonstrated and analyzed. The percentage of cycling cells decreases, according to the concentration, between 7.5 and 2.5 x 10(-5) M. Estimation of DNA by cell flow cytophotometry shows an important shift in the distribution of cycling cells with a relative decrease of G1 cells and a very important accumulation of G2 cells. According to our experimental conditions, the blocking up in G2 is irreversible only at 7.5 x 10(-5) M.     

Antagonistic action of E and F series prostaglandins upon mineralocorticoid production by the human adrenal

Summary At long time intervals, the E and F prostaglandins exert antagonistic effects on aldosterone production in vitro. At short intervals the E prostaglandins tend to mimic the inhibitory effect of the PGF series.     

The effects of some tetracycline derivates on Ehrlich ascites carcinoma and HeLa cells in vitro

Zusammenfassung In-vitro-Nachweis der Hemmung der Proteo- und Nukleosynthese in den EAC-Zellen, sowie des Wachstums der HeLa-Zellen mit folgenden Derivaten des Tetrazyklins: Anhydrotetrazyklin, 4, 12-Anhydrodedimethylaminotetrazyklin und 12-Deoxydedimethylaminotetrazyklin.     

Age-related differences in the urinary excretion of prostaglandin F2 alpha catabolites in the rat

Tritium-labeled PGF2 alpha was administered i.v. into rats of varying ages (2, 4, 6 weeks and adult). Urine was collected and assayed for radioactive products by thin-layer-chromatography. Results showed a distinctly different urinary profile between the 2-week-old and the adult rat. While the urinary pattern from the 2-week-old rat gave a single less polar product than PGF2 alpha, the pattern from the adult rat gave products more polar than PGF2 alpha. Urine from the 4- and 6-week-old rats gave a mixture of these types of products. These results indicate that some prostaglandin catabolic pathway (likely the omega-oxidative system) is activated in vivo within the 4-6 week postnatal period in the rat.     

Stimulation of gastric secretion by prostaglandin F2 alpha in rats.

In rats with chronic gastric fistulas, prostaglandin F2 alpha stimulated the gastric acid secretion in graded doses of 50, 100, 200 and 400 microgram/kg b.wt, while higher doses above 1 mg/kg b.wt tended to inhibit significantly. The gastric antisecretory effect of prostaglandin E1 could not be altered or modified by subsequent treatment of prostaglandin F2 alpha, while the latter alone without any prior treatment of the former, stimulated output of gastric juice, HCl and pepsin without significantly affecting the concentration of these components.     

Correlation between the susceptibility of E. coli to phagocytosis and their ability to invade HeLa cells in vitro

Summary The susceptibility of several strains of E. coli to phagocytic killing by polymorphonuclear leucocytes and the ability of the same strains to invade HeLa cells were studied. It was found that only the strains resistant to killing by leucocytes were able to penetrate and multiply within HeLa cells.Acknowledgments. We thank Dr Bianca Pani who supplied us with HeLa cells. Supported by grant No. 75.00695.04 from the National Research Council of Italy (CNR).     

A postsynaptic alpha 2-receptor: the alpha-adrenergic receptor of hamster white fat cells

The effects of selected alpha-agonists and alpha-antagonists on theophylline-induces lipolysis were investigate in isolated hamster white fat cells, alpha 2-Agonists (tramazoline, clonidine) inhibited theophylline-induced lipolysis while in alpha 1-agonist (methoxamine) was without any effect. The inhibitory effect of alpha 2-agonists was suppressed by yohimbine (alpha 2-antagonist), whereas alpha 1-antagonists were inefficient. This result implies that the alpha-adrenergic receptor of hamster fat cells is of the alpha 2-type, although postsynaptically.     

Effect of sodium butyrate in combination with prostaglandin E1 and inhibitors of cyclic nucleotide phosphodiesterase on human amelanotic melanoma cells in culture

Summary Sodium butyrate and cyclic AMP-stimulating agents (prostaglandin E₁, papaverine, theophylline, and RO20-1724) caused reductions in the cell number (primarily due to reduction in cell division) when added individually to human melanoma cells in culture. However, the combination of sodium butyrate with one of the cyclic AMP-stimulating agents produced a marked reduction in cell number (primarily due to cell death).Supported in part by BRSG grant RR-05357 awarded by Biomedical Research Support Grant Program, Division of Research Resources, National Institutes of Health. We thank Marianne Gaschler for her technical help.     

Effects of prednisolone and butyrate on agglutinability of HeLa cells by concanavalin A

Cellular and Molecular Life Sciences - Agglutinability by concanavalin A was measured with HeLa65 cells grown with prednisolone or sodium butyrate, 2 compounds that increase the activity of the...