Adenosine promoted accumulation of adenosine 3′,5′-monophosphate in rabbit vagus nerve

Summary Desheathed rabbit vagus nerve has been found to form cyclic AMP when incubated with adenosine. This accumulation of cyclic AMP is inhibited by theophylline but not by antiadrenergic agents, anticholinergic agents or local anaesthetics. Depolarizing media are not able to promote cyclic AMP accumulation in this preparation.Acknowledgment. We gratefully acknowledge Mr.G. Jones for valuable discussion, MrsM. Moosmayer and Mr.S. Ferrara for expert technical assistance and Swiss National Science Foundation for grant support (Nr. 3.478.0.75).     

Particle aggregates in plasma and intracellular membranes of toad bladder (granular cell)

Summary Freeze-fracture of granular cells of toad urinary bladder (Bufo marinus) reveals the presence, hitherto undescribed, of intramembranous particle aggregates in intracytoplasmic structures (tubules, vacuoles and vesicles) both in resting and vasopressin-stimulated epithelia.This work was supported by grants No. 3.553.75, 3.120.77 and 3.1300.73 from the Swiss National Science Foundation.The authors are indebted to Mrs Marthe Sidler-Ansermet, Miss Jacqueline Rial and Mr Michel Bernard for valuable technical assistance.     

Disparate Na+-requirement of taurocholate and indocyanine green uptake by isolated hepatocytes

Summary Uptake of both taurocholate and indocyanine green (ICG) by isolated rat hepatocytes was saturable and obeyed Michaelis-Menten kinetics. Only uptake of taurocholate exhibited Na⁺-dependence, a phenomenon compatible with active membrane transport. These findings suggest that the mechanisms responsible for hepatocellular uptake of bile acids and anionic dyes differ fundamentally.This work was supported by the Swiss National Science Foundation.The authors thank Mr Th. Weber for technical assistance.     

Membrane damage by coelomic fluid fromHolothuria polii (Echinodermata)

Summary Rabbit erythrocyte membranes lyzed byHolothuria polii coelomic fluid, observed under the electron microscope, present lesions consisting of irregular holes which are heterogeneous in size (ranging from 50 Å to 250 Å) and ultrastructurally different from the ring-like structure produced by human complement. The protein pattern associated with the lyzed membrane was also examined.Acknowledgments. I wish to thank Mr F. Veuthey for his excellent technical assistance. I express also my appreciation to Prof. N. Parrinello for advice and discussion. This work was supported partly by grant 3.083-0.84 from the Swiss National Science Foudation and partly (60%) by grant 1984 from Ministero Pubblica Istruzione, Italy.     

Actinomycin-resistant antiviral activity associated with preparations containing chicken interferon

Summary Crude and purified preparations containing chicken interferon show a 2fold antiviral activity. One is inhibited by actinomycin and leads to total inhibition if interferon is added to cells before actinomycin, the other is insensitive to actinomycin and leads to partial inhibition if interferon is added simultaneously with or after actinomycin.Work supported by the Swiss National Foundation, grant 3.399.70.The authors wish to thank Miss E. Browse, Miss U. Kohler and Mr U. Rohrer for excellent technical assistance.     

Yolk protein differences between species ofDrosophila

Summary 1–3 major proteins considered as vitellins or yolk proteins are detected in mature eggs from differentDrosophila species by gel electrophoresis on gradient slab gels. Qualitative and quantiative differences are found even between closely related species. In heteroplastic transplantations, no correlation was found between the similarity or dissimilarity of the protein pattern on the one hand, and success of failure of egg development and vitellogenesis on the other hand.We thank Mr B. Barandun for excellent technical assistance. This investigation was supported by the Swiss National Science Foundation, grant No. 3.792.76.     

The effect of Valium® anaesthesia on the radiosensitivity of the skin of the mouse foot

Summary Valium^® anaesthesia significantly reduces the effect of large single doses of X-rays on the mouse foot skin as compared with Nembutal^® anaesthesia. The radioprotective action of Valium may be attributed to a direct effect on the cells of the skin.Supported by the Swiss National Science Foundation (Grant no. 3.682-0.75).Acknowledgments. The authors wish to thank Miss F.T. Josuran, Miss U. Schärer and Mr P.P. Binz for their excellent technical assistance with the experiments.     

1,2-di-n-butylhydrazine dihydrochloride carcinogenesis in mice

Summary A solution of 0.0625% 1,2-di-n-butylhydrazine dihydrochloride (1,2-DBH) was given continuously in the drinking water of 6-week-old randomly bred albino Swiss mice for the remainder of their lives. The treatment gave rise to tumors of the lungs, lymphoreticular tissue and kidneys.     

Pancreatic polypeptide: A possible role in the regulation of food intake in the mouse. Hypothesis

Summary Pancreatic polypeptide (PP) is a recently identified hormone produced by pancreatic endocrine cells. The islets of genetically obese mice (ob/ob, C57 BL/6J), which are suspected to lack a circulating satiety factor, contain relatively few of the PP-producing cells. Administration of bovine pancreatic polypeptide (bPP) reduces food intake and suppresses body weight gain in the hyperphagic obese mice. It is postulated that PP participates in the regulation of food intake in a manner as yet undefined.This work was supported by grant No. 3.553.75 from Swiss National Science Foundation. We thank Mrs M. Eissler and Mr R. Cuche for their valuable help.     

An actin-destabilizing factor is present in human plasma

Summary Plasma and serum of humans or experimental animals contain a factor which destabilizes F-actin. The factor has no DNAse or thrombin activity and after incubation with F-actin does not modify the position of the actin band on a SDS polyacrylamide gel. Hence it probably depolymerizes F-actin.Acknowledgment. This work was supported by the Swiss National Science Foundation, grant No.3.692-0.76. We thank Drs M. Crippa and C.A. Bouvier for measuring the DNAse and thrombin activities. The technical help of Mrs M. Redard and A. De Almeida and the photographic work of Mr J.-C. Rumbeli and Mr E. Denkinger are gratefully acknowledged.     

Cytogenetic analysis of bone marrow cells and spermatogonia of male mice after in vivo treatment with arsenic

Summary Male Swiss Albino mice were injected i.p. with an As₂O₃ solution (0; 4; 8 and 12 mg As/kg) and sacrificed 12, 24, 36 and 48 h after injection. Neither chromatid nor chromosome aberrations were observed in bone marrow cells and spermatogonia.Acknowledgments. We thank Mr L. De Langhe for skillfull technical help. We acknowledge this work was supported by a grant of the Ministery of Public Health.     

Relation between stimulus intensity and neutrophil chemotactic response

Summary The effect of chemotactic peptides which lack chemokinetic activity has been investigated. The neutrophil response is proportional to the logarithm of the stimulus intensity, or alternatively a power function with an exponent of 0.3. Equal responses are obtained for equal ratios between the peptide concentration in the lower compartment and the threshold concentration. The significance of Weber-Fechner's law in leucocyte chemotaxis is discussed.We thank Miss B. Zanolari, Mrs M. Marti, Mrs Hauck and Mr Dietz for excellent technical assistance. This work was supported by the Swiss National Foundation for Scientific Research.     

Na,K-ATPase in the salivary gland of the ixodid tickAmblyomma hebraeum (Koch) and its relation to the process of fluid secretion

Summary Total and ouabain-sensitive ATPase activities were determined in the salivary glands of ticks throughout the feeding cycle. Activities were very low in unfed specimens. In the glands of feeding females, the activities rose until a maximum was reached for both ATPase components at approximately 200 mg. The activities remain low in males throughout the feeding period. These findings are discussed in relation to the fluid secretory process of the salivary glands.Generously supported by the Swiss National Fund for Scientific Research, request No. 3.3460.74 We are also very grateful to Mr.H. Bouvard, Ciba-Geigy Ltd., Les Barges, Vouvrey, VS, for supplying us with ticks.     

The delta sleep inducing peptide (DSIP). Comparative properties of the original and synthetic nonapeptide

Summary Both the original and the synthetic nonapeptide Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu enhance, in recipient rabbits, spindle and delta EEG activity as in orthodox slow wave sleep.Acknowledgment. This work was supported by grants from the Swiss National Foundation for Scientific Research (No. 3.871.72, 3.527.75,3.443.074, 3.780.076), Fonds für Lehre und Forschung der Universität Basel, Merck Sharp and Dohme (USA), Ciba-Stiftung Basel, Hoffmann La Roche Ltd Basel, Sandoz Ltd Basel. We received valuable help from Dr S. Roncari, Dr B. Wilson and Dr C. D. Bennett for chemical research, and from Prof. A. Cerletti, Dr H. J. Tobler and Mr J. J. Regez (Division of Application and Research Development, Sandoz Ltd) for data processing.     

Chemotaxis is not a special case of haptotaxis

Summary Serum peptides containing classical anaphylatoxin (CAT) produce marked chemotactic orientation of human neutrophil granulocytes without modifying cell attachment to the substratum. Furthermore gradients of adhesion produced with gammaglobulins fail to induce morphological orientation of neutrophils. The results suggest that chemotaxis is not a special case of haptotaxis.The excellent technical assistance of Miss M. Schuster, Mrs A. Damschen and Mr M. Arnold is gratefully acknowledged. This work was supported by the Swiss National Science Foundation and the Sandoz-Stiftung zur Förderung der Medizinisch-Biologischen Forschung.     

The effect of nicotine on ethanol-induced gastric ulcers in rats

Summary Nicotine, in concentrations of 5 and 25 g/ml drinking water, given ad libitum for 10 days, dose-dependently increased lesion formation and worsened ethanol-induced ulceration in rat stomachs. Daily fluid intake and b.wt gain were not adversely affected by nicotine pretreatment.The authors are grateful to Mr C.T. Luk for his skilled technical assistance.     

Comparative studies on the covalent binding of the carcinogen benzo(a)pyrene to DNA in various model systems

Summary The covalent binding of tritiated benzo(a) pyrene (BP) to DNA has been determined in rat liver in vivo, in rat liver perfused in situ, after incubation of BP with liver single cells, with liver homogenate, with liver microsomes and DNA, with fibroblasts from a rat granuloma pouch, and with 2 cell lines. Liver single cells were found to be a valuable compromise between the most sensitive system (microsomal incubation of BP with DNA) and the biologically most relevant system (in vivo).Presented in part at the 10th Annual Meeting of the Union of Swiss Societies of Experimental Biology, Experientia34, 925 (1978), abstract.Acknowledgment. We thank Dr G. Kistler, Institute of Anatomy, University of Zurich, for generously supplying the SIRC and VERO cell lines, and Mr P. Manser for the preparation of the granuloma pouch fibroblasts.     

Patterns of membrane organization in toad bladder epithelium: A freeze-fracture study

Summary Two cell-types of toad bladder epithelium show uncommon plasma membrane organization in freeze-fractured specimens. One type, the granular cell, contains a plasma membrane in which the A-face is poorly particulate luminally while the B-face discloses multiple large particles at this site. In contrast, the lateral and basal portions of the granular-cell membrane are typical in that more particles occupy the A-face than the B-face. In the other cell-type, which is mitochondriarich, the plasma membrane, luminally, laterally, and basally, contains rod-shaped and a few glubular particles in the A-face. We suggest that these two peculiar membrane organizations by considered in the localization of both vasopressin and aldosterone action in toad bladder.Some of these results were presented in abstract form at the 6th annual meeting of the Swiss Societies for Experimental Biology, Lausanne, 11–12, May 1974²¹ The authors are indebted to Mrs.Marthe Sidler-Ansermet, Mrs.Gorana Perrelet, MissMariella Ravazzola and Mr.Michel Bernard for valuable assistance.This work was supported in part by grants No. 3.0311.73, 3.8081.72, 3.553.75 and 3.1300.73 from Fonds National Suisse de la Recherche Scientifique, Bern, Switzerland, and by a grant-in-aid from Hoechst-Pharmaceuticals (Frankfurt-Hoechst, W. Germany).     

Preparation of isolated cells from rat heart

Summary Suspensions of isolated cells from rat heart were prepared and the data for viability and yield are given. Glucose uptake by the cells was mediated by a carrier system.The technical assistance of Mr.E. T. Potter, Mr.K. D. Patel and Mr.M. Griffin is gratefully acknowledged.     

Structure of two biologically active sesquiterpenoid amino-quinones from the marine spongeDysidea avara

Summary The structures of 2 minor constituents of the marine spongeDysidea avara, which induce developmental aberrations in sea-urchin eggs, are described. The structures were confirmed also by a simple synthesis from avarol (1).Acknowledgments. The authors wish to thank Mr A. Crispino for his skillfull laboratory technical assistance. Thanks are also due to Mr C. Di Pinto (NMR) and Mr A. Milone (MS).