Interaction of polyamines or their precursors with the calcium-controlled secretion of peroxidase by sugarbeet cells

Summary Three polyamines tested (cadaverine, spermidine and spermine) and their 2 precursors (the amino acids arginine and ornithine) inhibit the Ca²⁺-mediated secretion of peroxidases by sugarbeet cells in suspension culture at concentrations ranging from 10^–15 to 10^–5M. In the absence of exogenous Ca²⁺, spermine added at higher concentrations mimics the activatory effect of Ca²⁺, the other polyamines being without effect.Supported by the Belgian FRFC (grant No. 2.9009.75 to T.G.) and the Swiss National Foundation for Scientific Research (grant No. 3.140-0.81 to C.P. and H.G.).     

Hepatic and cerebral coenzyme a contents after intravenous injection of coenzyme a in rats

Summary Hepatic CoA concentrations and contents were significantly higher in rats having received i.v. CoA injections than in control rats. Maximum hepatic CoA concentrations were found 0.5–1 h after injection. In rat brain, no increase in CoA concentration was detected after i. v. injection of CoA.Acknowledgments. We thank MissV. Godly and MissA. M. Reber for excellent technical assistance. This work was supported by grants from F. Hoffmann-La Roche & Co., AG, Basel.     

Reappearance of HCG-receptors in immature rat ovary after HCG-treatment is not due to receptor synthesis

Summary In 24-day-old rats the reappearance of ovarian HCG-receptors after the injection of 200 IU HCG is independent of protein synthesis. The reutilization of occupied receptors in immature female rats is due to dissociation of the receptor-hormone complex.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 and Mrs Rita Rudolph for assistance and Mr A. Schlegel for radioimmunological determinations.     

Cardioactive peptides of the CNS of the pulmonate snailLymnaea stagnalis

Summary In the pulmonate snailLymnaea stagnalis the cardioactive effects (tested on isolated auricles) of acetylcholine (ACh), 5-hydroxytryptamine (5-HT), the bivalve tetrapeptide FMRFamide, and of chromatographically separated snail brain substances have been established. Besides ACh and 5-HT, in brain extracts, small FMRFamide-like and large cardioexcitatory peptides were found.     

Microbiological assay of cyclic 3′, 5′-AMP

Zusammenfassung Es wird ein mikrobiologisches Testverfahren beschrieben, mit dem sehr geringe Mengen von zyklischem Adenosin 3, 5-monophosphat quantitativ nachgewiesen werden können.     

A view on intramembraneous particles

Summary Intramembraneous particles of the outer membrane ofEscherichia coli show complementary pits on the opposite fracture face. This complementarity characteristic has been discussed in relation to the nature of the particle and the mode of fracturing.Acknowledgment. We thank Dr Lugtenberg for his active support and critical comments and Mrs J. Leunissen-Bijvelt for her technical assistance.     

Hemmung der Azetylierungsfunktion des Coenzyms A

Summary It is demonstrated that the acetylation of sulfanilamide and of p-amino-azobenzene, in the presence of pigeon liver extract and coenzyme A, is not only inhibited by -phenyl fatty acids but also by a considerable number of other substances. The most effective inhibitors contain at least two benzene nuclei and one acidic group (phenolic hydroxyl or a carboxyl group).