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1.
Summary Considerable acetylcholinesterase (AChE) activity was detected in anAedes aegypti established cell line. The enzyme is blocked by 10–6 M eserine sulfate, displays excess substrate inhibition and slowly hydrolyzes butyrylthiocholine. A 2-fold stimulation of AChE activity was shown after 2 days exposure to 3×10–7 M -ecdysone. AChE activity found in the fresh medium is the contribution of the fetal calf serum portion. A direct relationship between levels of serum and the AChE activity in the cultured cells was demonstrated.Acknowledgment. I wish to thank Dr J. Peleg of the Israel Institute for Biological Research for providing the starting culture ofAedes aegypti cells.  相似文献   

2.
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   

3.
Summary The incorporation of leucice-14C into protein in bovine mesenteric arteries was augmented by cyclic GMP (10–3 M) and decreased by cyclic AMP (10–3 M). There was no effect of 5 AMP (10–3 M). The phosphodiesterase inhibiting drugs theophylline (10–3 M) and papaverine (5×10–5 g/ml) both decreased the leucine-14C incorporation.We are indebted to Mrs.Lena Burlin for hear assistance. Finacial support has been provided by the Swedish State Medical Research Council (No. 04X-101X-4498).  相似文献   

4.
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   

5.
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   

6.
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   

7.
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   

8.
Summary 9 (10 mg/kg, i.p.) administered to mice immediately after withdrawal from a 3-day exposure to ethanol vapor was found to intensify withdrawal reactions. No effect was seen when 9 was administered chronically during the exposure to ethanol.  相似文献   

9.
Summary Cholinesterase, hyaluronidase, chondroïtinase and -glucuronidase are not inhibited by phenylbutazone in concentrations up to 10–3 M.Phenylbutazone accelerates the oxidation of the acids of the Krebs cycle in therapeutic concentrations up to 10 mg%; in higher concentrations it acts as an inhibitor. The inhibition of the -keto acid oxidation begins at lower concentrations of phenylbutazone then for the other intermediates.  相似文献   

10.
Summary A transfilter culture of the non-leguminous plantPortulaca grandiflora var. JR andRhizobium sp. cowpea 32H1 was established. Using15N2-analysis we demonstrated that15N-containing substances produced by the bacteria passed through the membrane and15N was enriched in the plant cells.Acknowledgment. The authors wish to express their gratitude to Prof. H. Marschner and Dr G. Hentschel for the determination of the nitrogen-content of our samples by the Dumasmethod and for advice on the optic emission method. Drs J. Burton, Milwaukee, Wisc., and Tjepkema, Oregon State University, are thanked for generous gifts ofRhizobium sp. cowpea 32H1. This work was supported by the DFG.  相似文献   

11.
Summary Ring fission ofp, p-DDT was studied in the rat following a single oral dose of 0.74 mg/kg (1.04 Ci) of uniformly ring-labeled14C-DDT. Expired air was passed through a solution of ethanolamine-ethylene glycol monomethyl ether (12) to trap14CO2. A total of 1.6% of the radioactivity administered was recovered in the expired air collected continually for 10 days, indicating that while degradation of the phenyl moiety is not a major route pfp, p-DDT metabolism in the rat, it is equal to the urinary excretion. Nevertheless, these results represent the most radical change accomplished in vivo of a residual insecticide yet reported in mammals.Acknowledgment. We acknowledge the secretarial work of Ms.Elaine Smolko. This study was supported by NIH fellowship No. 1 F22 ES01723-01 and No. HL16264.  相似文献   

12.
Summary The role of interferon (IFN) in controlling chronic infections ofListeria monocytogenes (Listeria) was studied in athymic C57BL/6nu/nu mice, and by treating thymectomized C57BL/6 +/+ mice with monoclonal rat CD4 and CD8-specific monoclonal antibodies (Mab). Mice treated with a combination of the two T cell subset antibodies were similar to athymic, nude mice in being able to contol Listeria infection, keeping the titers below 3–5 log10 bacteria per organ, but they could not eliminate them completely. Treatment with antibodies to IFN of nude or CD4+ + CD8+-T cell-depleted mice suffering from chronic Listeria infection caused a marked increase of Listeria titers, in liver and spleen. This result implies a role of IFN in maintaining anti-Listeria resistance in mice lacking mature T cells.  相似文献   

13.
Summary A procedure is reported for the large scale separation ofBordetella pertussis microorganisms from liquid culture media by tangential flow filtration (cross flow filtration) using anisotropic membranes with a cut-off limit of 1×106 daltons, and microporous membranes with a pore size of 0.22 m.  相似文献   

14.
Summary Rhynchosporium secalis (Oud.) Davis produces a phytotoxic compound with a mol. wt of 275×103 which is able to induce chlorotic symptoms in both susceptible and resistant barley leaves. Collectively, the data suggest that the toxin is a glycoprotein. Mild base treatment, by elimination, indicates that threonine and serine are involved in o-glycosidic linkages with the carbohydrate moiety. Sugar residues occur in the molecule in the ratio of mannose, rhammnose, galactose, glucosamine 13.6111.Acknowledgments. We acknowledge the assistance of Mr M. McNeil and P. Albersheim in doing the sugar analyses shown in this report. Financial support for this project was provided by a BARD grant 1-31-79, the French government, and the Montana Ag. Expt. Station.  相似文献   

15.
Riassunto La 1-metil-8-carbobenzilossi-aminometil-10-ergoline (MCE) impedisce la morte dei feti in ratte gravide trattate con enteramina (5-HT). L'effetto massimo è ottenuto quando l'MCE è somministrato 3 h prima della 5-HT, ma si manifesta anche 14 giorni dopo una iniezione del composto.  相似文献   

16.
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   

17.
Résumé Après injections bi-journalières de 9-THC à des grenouilles, nous avons calculé la durée de la perte du réflexe de redressement. La tolérance au 9-THC fut évidente après la seconde injection et, après la troisième, aucun effect ne fut visible. Ceci suggère que la tolérance se développe par le 9-THC, et non par ses métabolites, puisque les grenouilles n'ont pas de système enzymatique d'hydroxylation.  相似文献   

18.
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   

19.
Zusammenfassung Die Wirkungen von Aldosteron und 9-Halogenhydrocortison-azetaten auf das Überleben und Wachstum adrenalektomierter Ratten wurden studiert. Im Na/K-Ausscheidungstest zeigten sich 9-Chlor-hydrocortison-azetat bzw. 9-Fluor-hydrocortison-azetat 35-bzw. 10mal wirksamer als DCA und wiesen 1/3 bzw. 1/10 der Wirksamkeit von Aldosteron auf.  相似文献   

20.
Summary The anthocyanidin investigated here exists below pH 4 as a cationAH 2 + (wave length of absorption maximum max=459 mµ), between pH 5 and 7 in the neutral formAH ( max=492 mµ) and above pH 8 as an anionA ( max=537 mµ). At pH 5 the freshly dissolved substance is partially converted into a colourless formBH ( max=372 mµ) and a chemical equilibrium betweenAH andBH is reached within 1 h. A kinetic study of the process of formation ofBH shows that an intermediate productZ is formed. This process can be reversed by light exposure. It can be concluded from a kinetic investigation by using flash light thatBH is transformed by the absorbing light into a new substanceL ( max 275 mµ and 225 mµ), andL changes partially intoBH, partially intoZ, which itself is transformed partially intoAH 2 + ,AH,A , partially intoBH. The reactionZ AH,AH 2 + ,A is proportional to the concentration of protons [H +], the reactionZ BH independent of [H +]. Thus a photochemical production ofAH 2 + ,AH,A fromBH is readily obtained in the presence ofH + and not obtained in the absence ofH +.  相似文献   

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