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1.
Summary GABA (6×10–6 M) binding to synaptosome-enriched fractions of cat CNS exhibited a clear rostro-caudal gradient, whereas glycine (6×10–6 M) binding was greatest to particles of cerebellar cortex, and this was followed by medulla caudate nucleus cerebral cortex pons > corona radiata. Strychnine-SO4 (10–3 or 10–4 M) inhibited the binding of GABA and glycine in all brain regions studied; at 10–5 M this drug inhibited the binding of both GABA and glycine only to particles of the cerebral cortex.This study was supported by Centro Nacional Ramón y Cajal and Fundación Juan March. P. M. was a summer student from Eastern Nazarene College, Wollaston, Mass., USA.  相似文献   

2.
Summary Therapeutic concentrations of digitoxigenin (10–7–3× 10–7 g/ml), producing positive inotropic effects, did not alter resting and action potentials of electrically driven guinea-pig auricles. However, toxic concentrations of digitoxigenin (5 × 10–7–10–8 g/ml), producing arrhythmias and contracture of the myocardium, had a marked influence upon resting and action potentials and conduction velocity.  相似文献   

3.
Zusammenfassung Die Synthese von (—)-1(7)-Tetrahydrocannabinol (THC) auf (—)-1(6) wird beschrieben. Das Hauptprodukt der oxidativen Zerstörung von (—)-1-THC ist Cannabinol. Beschleunigte Versuche der Luftoxidation von (—)-1-THC und (—)-1(6)-THC haben gezeigt, dass das letztere beständiger ist. Dieser Unterschied kann mit der Reaktivität des C3-benzylisch-allylischen Wasserstoffes in (—)-1-THC erklärt werden.  相似文献   

4.
Summary The free enrgies of transfer (G t 0 ) of H+, Cl, Br, I and SCN ions from water to 10, 20, 30 and 40% dioxanewater mixtures have been studied from potentiometric measurements. For anions the G t 0 values are in the order Cl>Br>SCN>I.  相似文献   

5.
Summary Probenecid (100–750 g·ml–1) was found to inhibit cardiac contraction force in untreated and digoxin-treated (100 g·ml–1) isolated right guinea-pig atrium in vitro by a reversible process, without influencing beating frequency. At low concentrations (1.5–60 g·ml–1),14C-probenecid was accumulated into right atrium by an oxygen-dependent process. Correlation between uptake and negative inotropic action of probenecid could not be found.  相似文献   

6.
Zusammenfassung (–)-8-Tetrahydrocannabinol ist einer der Aktivstoffe in Marihuana (Cannabis sativa L.). Inkubation dieser Verbindung mit der überstehenden Zentrifugationsfraktion (9000g) aus männlicher Hundeleber ergab zwei Hauptmetaboliten, welche durch Massenspektrometrie und Kernresonanzspektroskopie identifiziert wurden. Den beiden Verbindungen werden die Strukturen des 1-Hydroxy-8-tetrahydrocannabinols und des 3-Hydroxy-8-tetrahydrocannabinols zugeordnet.  相似文献   

7.
Summary Hexoprenaline potentiated the14C-aminopyrine uptake (a reliable index of H+ generation) of isolated rat gastric cells stimulated by 10–6–10–4 mol/l carbachol, and inhibited that in response to 10–4 mol/l histamine without and in the presence of propranolol. It is concluded that hexoprenaline acts as a partial agonist on parietal cell H2-receptors and that -adrenoceptor activation may functionally modualte gastric acid secretion.Acknowledgments. S. Maliski, Institute of Rheumatology, Warszawa, held a fellowship of the Alexander v. Humboldt-Foundation. The study was supported by the Deutsche Forschungsgemeinschaft. The skilful technical assistance of Mrs R. Maier and Mr R. Beer is gratefully acknowledged.  相似文献   

8.
Summary The addition of insulin (10 U) to a suspension of isolated hepatocytes in Krebs-Ringer bicarbonate solution. causes an increase in the negative electrophoretic mobility of the cells from –1.68 m sec–1 V–1 cm to 2.26 m sec–1 V–1 cm. This observation supports the findings by other workers that the binding of insulin to its receptor leads to a marked change in the membrane.Acknowledgment. We wish to thank the Medical Research Council for the provision of the microelectrophoresis apparatus and initial running costs of the project.  相似文献   

9.
Enterocytes isolated from rat jejunum were tested for the existence of a Cl/HCO 3 exchange, previously evidenced in basolateral membrane vesicles but not in brush border. Cells were found to retain functional integrity and transport capabilities long enough to allow Cl fluxes to be measured. Both efflux and uptake experiments indicate that a Cl/HCO 3 antiport, inhibited by 4,4-diisothiocyanostilbene-2-2-disulfonic acid (DIDS), is functional under resting conditions.  相似文献   

10.
Zusammenfassung Es wird gezeigt, dass 3–5-cAMP (10–3 M) und Theophyllin (10–4 M) die Permeabilität derjenigen Lysosmen-Membranen steigern, die aus Rattenleberzellen in bezug auf saure Phosphatase and in bezug auf -Glucuronidase-Enzyme präpariert wurden.  相似文献   

11.
We show that -immunoglobulin (IgG) binds calmodulin (CaM) in a Ca2+-independent manner, with Kd value of (1.7±0.5)×10–7M. A single IgG molecule maximally bound 10 CaM molecules. The binding is to the heavy chain or Fab portion, but not the Fc portion, of the IgG molecules. Ca2+ greatly diminished the interaction between IgG and CaM, with IC50=8–9M. These data give a novel insight into protein-protein interactions.  相似文献   

12.
Summary 2, 4-dichlorophenol (DCP), 2, 4-dinitrophenol (DNP) and 2, 4-dinitro-o-cresol (DNC) applied at a concentration of 1.10–7 to 1.10–3 M, produce a dramatic increase in IAA-oxidase activity in young cells ofLens root. IAA destruction by breis from root tissues was inhibited by Mn++ ion at low concentrations of DCP (1·10 to 1.10–7 M), but was enhanced by Mn++ ion at higher (1.10–5 to 1.10–3 M) DCP levels.

Ce travail a pu être entreprise grâce à l'appui duFonds national suisse pour la Recherche scientifique.  相似文献   

13.
Summary A new synthetic phenyl-ethyl-amine derivative, the 2-[N- (3, 4-methylen-dioxyphenylethyl)-methylaminomethyl]-tetrahydrofuran, No. 11 081, exhibits a strong protective effect against cardiac fibrillation and arrhythmias produced by various experimental methods: against fibrillation due to aconitine 3 × 10–8 on the isolated cat's heart, it is active in a concentration of 10–6–2 × 10–6. Against cardiac arrhythmias produced in the cat by adrenaline + CHCl3 or cyclopropane, it shows a protective effect by 5–10 mg/kg i.v. and even perorally by 50 mg/kg. In these tests, the antifibrillatory activity of the new compound seems to be roughly the same as that of -fagarine, and higher than that of procaine.

9e communication sur les dérivés des alcoylène-imines; 8e communication, cf. Exper.10, 261 (1954).  相似文献   

14.
Riassunto Sono state calcolate le costanti di dissociazione dei complessi fra la RNA-polimerasi II e la metil--amanitina, la -amanitina e la metil-aldoamanitina. La K d è risultata essere 3.6×10–9 M per la metil--amanitina e 3.2×10–9 M per la -amanitina. La metil-aldoamanitina non si lega all'enzima.  相似文献   

15.
Summary (–)-8-Hydroxymethyl-1-tetrahydrocannabinol (THC)1, a novel analog of 1, is shown to be as active as 1 and twice as active as 1 in the dog ataxia test.Acknowledgment. This work was supported by NIDA (Grant Nos. DA-00574-01 and DA-00490).  相似文献   

16.
Riassunto È stata studiata con metodi istochimici la distribuzione della 5-3-idrossisteroide deidrogenasi ( 5-3-HSDH) e delle 17-idrossisteroide deidrogenasi (17-HSDH), DPN- e TPN-dipendenti, nell'ovario di gallina ovulante. Mentre la 5-3-HSDH è presente in tutti i tessuti a secrezione steroide dell'ovario, la 17-HSDH è localizzata solo nelle cellule della granulosa.  相似文献   

17.
Mean plasma insulin concentration was reduced and mean plasma glucose concentration increased following the administration of N-nitro-L-arginine methyl ester (L-NAME; 100 mol kg–1 i.a.) in conscious calves given continuous infusions of exogenous glucose (30–60 mol min–1 kg–1 i.v.). It is concluded that the rise in plasma insulin concentration which occurs in these animals in response to glucose is mediated, at least in part, by a nitric oxide-related factor (NOx).  相似文献   

18.
Résumé Nous avons observé que le iodoacétate en concentrations de 1·10–4, 5 · 10–5 et 1 · 10–5 M et préalablement incubé à 37 °C, a une influence de l'ordre de 61, 50 et 44% respectivement sur la totalité du pouvoir antigénique de l'insuline de buf. L'effet inhibitif est proportionnel à la durée d'incubation et l'on ne constate pas de différences lorsque les concentrations de l'hormone se trouvent entre 100 et 300U/ml.  相似文献   

19.
Zusammenfassung Es wurde der Hemmungseffekt von Colcemid und Vincristin auf die Méiose bei Mäuseeiern in vitro und in vivo untersucht. Die in vitro wirksame minimale Konzentration für Vincristin wurde bei 4×10–7 g/ml, für Colcemid bei 4×10–3 g/ml gefunden. Die in vivo wirksame Minimaldosis von Vincristin war 1 g/g. Körpergewicht, von Colcemid 10 g/g Körpergewicht.

Part of this data was presented in abstract in Clinical Research, vol. XV, No. 2, April 1967, p. 268.  相似文献   

20.
Waste water purification is characterized by intensive mineralization and nitrification processes. Because of the high O2 demand, temporarily anaerobic conditions may be produced, and denitrification by nitrifying organisms as well as heterotropic denitrification may contribute to N2O release. In situ measurements (1993–1994) suggest that N2O is released from activated sludge in a domestic waste water treatment plant at an average rate of 1040 g m–2h–1 with a range between zero and 6198 g m–2h–1. The production of N2O seems to be related to the concentration of NO 2 and NO 3 as well as to the pH. In the waste water about 75–200 g N2O l–1 is dissolved. This N2O is released after discharge into the receiving waters. The N2O is produced essentially by nitrification rather than by heterotropic denitrification. On a long-term scale the increasing use of mechanical-biological waste water purification plants world-wide may add increasingly to the anthropogenic production of N2O, although the present amount of N2O produced is negligible compared to its global terrestrial production.  相似文献   

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