Na+/NH 4 + co-transport in isolated perfused gills of the Chinese crabEriocheir sinensis acclimated to fresh water

Summary In isolated perfused posterior gills ofE. sinensis acclimated to fresh water, NH ₄ ⁺ may be used as a counter-ion for Na⁺ active transport. This Na⁺/NH ₄ ⁺ coupled transport can, however, only account for a small part of the Na⁺ total active influx.Chargé de Recherches du FNRS-Acknowledgments. This work has been aided by a grant crédit aux chercheurs from the FNRS and by a grant No. 2.4511.76 from the FRFC.     

A novel cannabinoid containing a 1,8-cineol moiety

Summary The synthesis of a novel cannabinoid containing a 1,8-cineol moiety (1) is described. It is much less biologically active than ¹-tetrahydrocannabinol.Acknowledgment. This work was supported by NIDA (grant No. DA-00574-01).     

Endocytosis and inositol hexakisphosphate levels inras transformants ofDictyostelium discoideum amoebae

Summary Fluid-phase pinocytosis kinetics and lysosomal enzyme secretion parameters were measured inDictyostelium discoideum amoebae constructed from strain AX3 by transformation with a multicopy plasmid carrying either a normalras gene (ras-Gly12), a mutatedras gene (ras-Thr12) or by the vector carrying the geneticin resistance gene only (pDNEO2). It was found that the pinocytosis rate and extent as well as the lysosomal enzyme secretion were slightly different in the three strains. These changes, however, were related to minor modifications of the cellular volumes. The overall concentration of inositol hexakisphosphate was similar in the three strains.This work was supported in part by a grant from the Ligue Nationale Française contre le Cancer (n^o 880258) to MS, and by a grant from the Fonds National Suisse de la Recherche Scientifique (No. 3.623-087) to CR.     

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.).     

Influence of 2-methyl-2-(p-1,2,3,4-tetrahydro-1-naphthylphenoxy)propionic acid on the oxidation of cholesterol by rat liver mitochondria

Zusammenfassung Es wird gezeigt, dass bei männlichen Wistar-Ratten im 3-Wochen-Diätexperiment mit Zusatz von 0,3% 2-Methyl-2-(p-1,2,3,4-Tetrahydro-1-naphthylphenoxy)-Propionsäure (Su-13437) die Oxydation von 26-¹⁴C-Cholesterin zu¹⁴CO₂ durch Lebermitochondrien (bezogen auf mg/N) ähnlich wie bei den Kontrollen war. Bei den Versuchstieren war jedoch bei Abwesenheit von Cytosol im System die Oxydation durch Lebermitochondrien erhöht.

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Acknowledgment. This work was supported, in part, by a grant No. HE-03299 and a Research Career Award No. 4-K6-HE-0734 from the National Heart Institute, N.I.H. We are indebted to Dr. W. I.Taylor, CIBA Pharmaceutical Co., Summit, N.J., for the generous gift of Su-13,437.     

Drug modification of silver-induced sodium transport across toad skin

Summary Stimulation of active Na⁺ transport in the toad skin by antidiuretic hormone (ADH) and p-chloromecuribenzoate (P-CMB) was blunted by the presence of silver (Ag⁺). Amiloride inhibited active Na⁺ transport, equivalently, whether Ag⁺ was present or not.This work was supported by the Nephrology Training grant from the National Institute of Arthritis and Metabolic Diseases (1-TO1-AM-05697-02 and –03) and by Whitehall Foundation grant No. 78-156 ck-1 DSR.     

Phosphoglucomutase polymorphism in the rainbow trout,Salmo gairdneri

Zusammenfassung Es wird aufgrund von Stärke-Gel-Zymogrammanalysen der Phosphoglukomutase in 72 Forellen (Salmo gairdneri) die Existenz eines polymorphen und zweier nicht variierender Gene ermittelt. Der Polymorphismus beruht auf 2 Allelen mit übereinstimmenden Frequenzen im Hardy-Weinberg-Gleichgewicht.

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Supported in part by a grant No. CA-05138 from the National Cancer Institute, U.S. Public Health Service and in part by Animal Resources grant No. FR00433.     

Inhibition of steroidΔ 4 reductase by heparin: Studies with desoxycorticosterone,progesterone, androstenedione and testosterone

Zusammenfassung Heparin hemmt die Reduktion der Doppelbindung in 4-Stellung des Rings A einer Reihe von C-11-desoxy, ⁴-4-keto-Steroiden in der Rattenleber. Es scheint, dass Heparin mit NADPH um das Steroid-reduktase-Apoenzym konkurriert.

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This work was supported by grant No. AM-09151 from The National Institutes of Health, U.S.P.H.S.     

Experiments on the mechanism of the inhibition of mitochondrial Ca2+ transport by La3+ and ruthenium red

Summary The effects of La³⁺ and ruthenium red on the energy-linked uptake of Ca²⁺ mediated by a synthetic neutral Ca²⁺ ionophore have been investigated in rat liver mitochondria. The results indicate that unspecific surface charge effects do not play a major role in the mechanism of inhibition of mitochondrial Ca²⁺ transport by La³⁺ and ruthenium red.Acknowledgments. The authors are indebted to Prof. W. Simon, ETH Zurich, for having provided samples of the synthetic neutral Ca²⁺ ligand, and to M. Mattenberger for the valuable technical assistence. The work was supported by a grant of the Swiss Nationalfonds (grant No. 3.1720.75).     

Late DNA replication in the sex chromosomes ofDidelphis virginiana

Zusammenfassung Autoradiographisch wurde die späte DNS-Synthese derX- undY-Chromosomen vonDidelphis virginiana (Virginia Opossum) in Knochenmarkzellen untersucht. Die weiblichen Tiere zeigen typische späte Reduplikationsmuster in einemX, die männlichen das späte Reduplikationsmuster inX undY und inY allein.

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This study was supported in part by research grant No. AM-02504 and training grant No. Tl-AM-5277, National Institutes of Health. Dr.Reiss was a predoctoral trainee, National Institute of Arthritis and Metabolic Diseases, U.S. Public Health Service.     

Presence of calcium ions as a requisite for the in vitro stimulation of TSH-release by hypothalamic TRF

Résumé L'incubation in vitro de fragments d'hypophyse (rat) dans le liquide de Krebs-Ringer sans calcium (Ca⁺⁺) inhibe l'action du facteur hypothalamique TRF (TSH-releasing factor) qui normalement stimule la sécrétion de l'hormone thyréotrope (TSH). La ré-introduction de l'ion Ca⁺⁺ (2.54 mM) rétablit la réponse (sécrétion de TSH) au facteur TRF.

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Supported by USPHS research grants Nos. AM 08290.04, HD 02577.01, training grant No. GM 956.04; also No. FR 00254 to Common Research Computer Facility, Texas Medical Center. We are pleased to acknowledge the excellent assistance of Mrs.Nancy Pace in the assays involved here.     

Effect of benzimidazole on nicotinamide adenine dinucleotide phosphate phosphomonosterase activity in wheat leaves

Summary Nicotinamide adenine dinucleotide phosphate phosphomonoesterase was isolated and partially purified from wheat (Triticum aestivum L. var. Selkirk) leaves. The enzyme hadK _NADP value of 1.4×10^–4 M and a pH optimum of 5.9.In vitro activity of this enzyme was unaffected by precursors of NAD (nicotinamide and nicotinic acid) or cytokinis (kinetin and benzimidazole). However, when detached wheat leaves were treated with solutions of these compounds, the precursors lowered the specific activity while the cytokinins enhanced the activity. It is suggested that spatial separation and compartmentation of the enzyme and its substrate NADP account for the similar effect of benzimidazole on both.This work was supported by a grant No. A2698 from the National Research Council, Canada.     

Characterization of the estrogen receptors in the uterine and blood eosinophil leukocytes

Summary Estrogen receptors are found in the rat uterine and in the eosinophil-rich human blood leukocyte 24,000g fractions, but not in the low-eosinophil count human blood leukocyte 24,000g fraction. The total number of binding sites per blood eosinophil leukocyte is 7,400 sites per cell, and theK _d =5.6×10^–10 M.Acknowledgments. This work was supported in part by funds from the Unité de Recherches sur le Métabolisme Moléculaire et la Physio-Pathologie des Stéroïdes de l'INSERM, Hôpital de Bicetre, France, and by grant No. 2015 from the Oficina Técnica de Desarrollo Científico y Creación Artística of the University of Chile.     

The visual response of the purple shore crab,Hemigrapsus nudus,to ionizing and non-ionizing radiations

Zusammenfassung Im Krabbenauge vonHemigrapsus nudus entstehen elektroretinographische Reaktionen (ERG) mit sichtbarem Licht und Röntgenstrahlung, die andeuten, dass dieselben Rhodopsin-Erregunsprozesse mit beiden Strahlungsarten stattfinden. Nach⁹⁰Sr--Strahlung wird angenommen, dass Cerenkov-Effekt- und induzierte Fluoreszenz-Lichterzeugung die-ERG-Reaktion deutlich beeinflussen.

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This research was conducted under a grant from the Environmental Control Administration, CPEHS, U.S. Public Health Service No. EC00119.

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Public Health Service Radiological Health Fellowship No. 97996-06-69.     

Kynurenine localization in the egg ofDrosophila melanogaster

Zusammenfassung Papierchromatographische und fluoreszensmikroskopische Untesuchungen von Ovarien der Wildtypen und der Vermilion- und Cinnabar-Mutanten vonDrosophila zeigen, dass sich Kynurenin (der Hauptbestandteil der fluoreszierenden Komponente des Eies) in den proteinhaltigen Dotterschollen des reifenden und des reifen Eies befindet.

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Supported in part by NIH grant No. GM 14891 and a grant from the Research Foundation of the State University of New York.     

Effects of propafenone on TEA-induced action potentials in vascular smooth muscle of canine coronary arteries

Summary The Ca⁺⁺-dependent, TEA-induced action potential is blocked by propafenone in a dose-dependent manner. Such results suggests that in coronary arterial smooth muscle one mechanism of action of propafenone is to inhibit Ca⁺⁺ inward current.This research was supported by a grant from the Tennessee Affiliate of the American Heart Association and VA grant No. 1A (74)111-430100). The authors wish to thank Dr Gerhard Pfennigsdorf for supplying us with propafenone. We also wish to thank Ms Penny Williams for her technical assistance.     

A cannabinoid with cardiovascular activity but no overt behavioral effects

Summary Abnormal-⁸-tetrahydrocannabidiol (ABN-⁸-THC) failed to elicit central nervous system and cardiovascular effects in laboratory animals. Abnormal-cannabidiol (ABN-CBD) was also devoid of overt behavioral effects but produced marked hypotension with only slight bradycardia in anesthesized dogs.Acknowledgment. This work was supported by NIDA (grant No. DA-00574-01 and DA-00490) and Virginia Heart Society (grant No. RR-05697)     

On the interaction of hypoxanthine with adenine

Résumé Une conversion non-enzymatique d'hypoxanthine en adénine fut proposée sur la base d'observations spectrophotométriques obtenues de solutions contenant adénine et hypoxanthine dans 1–5M de phosphate d'ammonium. Les résultats fournis par les expériences sur la radioactivité ne confirme pas la conclusion émise parBowne ² que hypoxanthine et adénine agissent l'une sur l'autre en solution concentrée de phosphate d'ammonium pour former de l'adénine.

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This work was supported by United States Public Health Service Grants No. AM-08897, No. AM-10126, and No. 2A-5124; a grant from The Arthritis Foundation (Northern California Chapter); and from the Committee on Research, University of California School of Medicine (San Francisco).     

Cell fusion as a mechanism for the origin of polyploid cells in vitro

Zusammenfassung In Kulturen vonPeromyscus maniculatus und inMuntiacus muntjak wurden Tetraploidzellen gefunden, die als Produkte von Zellfusionen aufgefasst werden. Es wird angenommen, dass die ursprünglichen diploiden Elemente sich im Zeitpunkt der Fusion in verschiedenen Phasen des Zellzyklus befunden haben.

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Supported in part by NIH fellowship No. 1-F02-CA-42, 531-02 from the National Cancer Institute, USPHS grant No. GM-15361, and Grant No. E 286 from the American Cancer Society.