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1.
The Ca2+ ionophore ionomycin induced cytosolic [Ca2+]i elevation as well as strong activation of Cl efflux in mouse mammary epithelial cell lines expressing wild-type or mutated (deletion of phenylalaline 508) cystic fibrosis transmembrane conductance regulator (CFTR) or vector. Ionomycin-induced Cl efflux was abolished by the intracellular Ca2+ chelator 1,2-bis(2-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid, whereas both activators and inhibitors of phospholipase A2 had no effect, indicating the involvement of Ca2+-dependent Cl- channels. Stimulation of arachidonic acid release by ionomycin and phorbol ester was not significantly different between wild-type or mutated cell lines, whereas vector-transfected cells exhibited a significant higher release, which was shown to be due to larger amount of immunoreactive cytosolic phospholipase A2. These results indicate that phospholipase A2 activity of C127 cells was not influenced by the presence of wild-type or mutated CFTR. Received 27 April 1999; received after revision 11 June 1999; accepted 23 July 1999  相似文献   

2.
The composition of the Dufour gland of the antC. scutellaris has been reinvestigated by gas chromatography/mass spectrometry. The major components of the gland are (2E,5E,12Z)-4-oxoheneicosa-2,5,12-trien-1-ol acetate (1a) its 14 and 16 double bond isomers (1b and1c), and the corresponding (Z,Z)-dienes5a and5b, all containing an acetylated C21 chain. The previously proposed structures1d, 1e, and5c, which are based on an homologous acetylated C23 chain, correspond to minor derivatives present in the gland. Traces of acetylated C19 homologs, tentatively identified as1g-1i, have also been found. The Dufour gland contents of the two other EuropeanCrematogaster species have also been studied.C. auberti is very similar toC. scutellaris in producing mainly1a, 1b and1c, together with the same higher and lower homologs, but it lacks the dienic derivatives5, whereasC. sordidula contains essentially the acetylated C19 compounds1g, 1h, and1i, accompanied by acetylated C17 homologs.  相似文献   

3.
Summary Isolated rat hearts were subjected to hypoxic perfusion on a recirculating Langendorff apparatus. Following a 30-min-period of aerobic stabilization the hearts were perfused for 30 min with media equilibrated with 84% N2, 12% O2 and 4% CO2. At the end of the hypoxic period myocardial concentrations of cyclic AMP and cyclic GMP were determined by radioimmunoassay. Exposure to hypoxia resulted in a significant increase in cyclic AMP (p<0.01) and a decrease in cyclic GMP (p<0.05) as compared to hearts perfused for 60 min with media gassed with 96% O2, 4% CO2.Acknowledgment. We gratefully acknowledge the excellent technical assistance provided by Mrs Inger O. Boggs and Miss Patricia C. Hannigan. This work was supported in part by U. S. Public Health Service grant HL 14661 from the National Heart and Lung Institute, and by a grant from the Central Ohio Heart Chapter.  相似文献   

4.
Summary (1 R) [1-3H,2H1] 3-Phenylpropanol, the key intermediate in the synthesis of (4 R) [4-3H,2H1] D, L-homoserine and of the (4 S)-isomer, is obtained from (1 S) [1-2H1] 3-phenylpropanol and (1 RS) [1-3H] ethanol upon incubation with yeast alcohol dehydrogenase and NAD+; under similar conditions 2-phenylethanol undergoes very small exchange with [1-2H2] ethanol.  相似文献   

5.
Zur Stereochemie der Propandioldehydrase-Reaktion   总被引:2,自引:0,他引:2  
Summary Propanedioldehydrase is shown to convert both (+)-(S)-2-2H-propanediol,3, and (–)-(R)-1-2H2-propanediol,5, to specimens of deuterated propion-aldehyde, for which the (S)-configuration has been established. Thus, in the propanedioldehydrase reaction migration of hydrogen atoms from C–1 to C–2 always occurs with inversion of configuration.  相似文献   

6.
A highly potent attractant of zoospores ofAphanomyces cochlioides, a causal fungus of the root rot disease of spinach (Spinacia oleracea), was isolated from spinach roots, and its structure was determined by spectroscopic evidence and chemical synthesis as cochliophilin A (5-hydroxy-6,7-methylenedioxyflavone,1). A chromosorb particle prepared by soaking in solution of1 showed a potent attracting activity toward the zoospores using concentrations of1 above 10–9 or 10–10 M.  相似文献   

7.
Summary For the first time we have isolated a major psychoactive cannabinoid, (3R, 4R)- 1(6)-tetrahydrocannabinol3 from callus cultures ofCannabis sativa L.3 was obtained as an artefact of the actually formed (3R, 4R)- 1-tetrahydrocannabinol-3- and/or 5-carboxylic acids1 and2 by subjecting the culture material to a decarboxylation step prior to extraction. No attempt was made to isolated acids1 and2. The identity of3 was confirmed by comparison with an authentic sample of (3R, 4R)- 1-tetrahydrocannabinol. Culture conditions, isolation procedure and identification of the cannabinoid are described.Acknowledgment. The authors are greatly indebted to Dr W. Heller and Dr G. Schroeder-Frey for deriving the callus cultures from seedlings ofC. sativa and to Prof. N. Amrhein for valuable gifts of culture media and growth regulators.  相似文献   

8.
Besides the known sarmentogenin 3-O--D-allopyranoside (1) and digitoxigenin-3-O-[-D-xylopyranosyl-(14)-2, 3-di-O-acetyl--D-allopyranoside] (4), four new cardiac glycosides (2, 3, 5 and6) have been isolated from the defensive glands of adults ofChrysolina fuliginosa. The structures of the new compounds were determined by1H NMR at 600 MHz and FABMS. Compounds1–6, present in the adults ofC. fuliginosa, have also been identified in the eggs.  相似文献   

9.
Summary N, N, N, trimethyllysine and an unidentified methylated amino acid which co-electrophoresed and cochromatographed with the hydrolysis product of S-adenosyl-L-methionine, occur in fetal canine cardiac myosin and are isotopically labeled in vitro with S-adenosyl-L-(methyl3H) methionine between the 10th and the 12th day of culture.  相似文献   

10.
Summary From the plantCentaurium cachanlahuen, swertiaperenine1, swercherine2, decusatine4, oleanolic acid5 and the xanthone 1,8-dihydroxy-2,3,4,6-tetramethoxy-9H-xanthone3 were isolated and characterized.  相似文献   

11.
Summary The solid phase synthesis of three invertebrate vasopressin-oxytocin homologs: AVP-like factor, F1 1, ([Leu2, Thr4] AVT)2 isolated from subesophageal and thoracic ganglia ofLocusta migratoria 3, Arg-conopressin-S4. ([Ile2, Arg4] AVT), Lys-conopressin-G4 ([Phe2, Arg4] LVT), both isolated from the venom of fish-hunting marine snails of the genusConus and six of their analogues is reported. These analogues are: [Arg4] AVT, [Ile2] AVT, [Leu2] AVT, [Phe2, Arg4] AVT, [Arg4] LVT and [Ile2, Arg4] LVT. All peptides were tested for antidiuretic and vasopressor activities.  相似文献   

12.
Zusammenfassung Durch Messungen in 10–5, 10–4 und 10–3 N benzolischen Lösungen von Zn-di-i-propylsalizylat haben wir einen beträchtlichen Einfluss von Turbulenz auf Strömungsströme feststellen können. Dieser Einfluss kann ausgedrückt werden durch einen Faktorf, der in einem unserer Experimente einen Wert vonf=66 erreichte; aus den Werten vonf kann die Dicke der diffusen Doppelschicht in der Flüssigkeit berechnet werden.  相似文献   

13.
Human umbilical vein endothelial cells (HUVECs) in primary cultures were perfused under normoxic or hypoxic conditions. These cells were stimulated twice for 3 min by increased flow (from 0.5 to 3.0 ml/min). Under hypoxic conditions the basal release of ATP was the same as under normoxic conditions, but during increased flow the release was greater (0.58±0.07>0.32±0.04 pmoles/ml/106 cells (+78%), for the first period of stimulation; 0.39±0.05>0.22±0.03 pmoles/ml/106 cells (+79%) for the second period). Further experiments with sequential increments in flow rate showed that under both normoxic and hypoxic conditions, a positive correlation existed between ATP release and the rate of flow but there was always more ATP released under hypoxic conditions regardless of the flow rate.HUVECs in secondary culture (second passage) were similarly stimulated. No differences were observed between normoxic and hypoxic conditions. In both cases, the quantity of ATP released during high flow (0.050±0.004 pmoles/ml/106 cells) was significantly smaller than the quantity of ATP released during low flow (0.09±0.01 pmoles/ml/106 cells).To conclude, since hypoxia alone did not affect ATP release, there appears to be a synergistic relationship between increased shear stress and hypoxia in the stimulation of ATP release from HUVECs. Moreover, the release of ATP under these conditions seems to be a property of highly differentiated endothelial cells.  相似文献   

14.
Summary Total synthesis of cannabispiran (1) was accomplished by a biomimetic-type cyclization of the bibenzyl2, using K3Fe(CN)6 or MoOCl4.Acknowledgment. Supported in part by the Research Institute of Pharmaceutical Sciences, School of Pharmacy, University of Mississippi.  相似文献   

15.
Summary 5,5-Diphenylglycocyamidines bearing an alkyl group in position 3 are partly rearranged to the corresponding N2-alkyl derivatives on heating with alcoholic ammonia in the presence of ammonium acetate. Prolonged heating with ammonium acetate leads to N-dealkylation both of N3- and N2-alkyl derivatives. 5,5-Diphenylglycocyamidine in turn is mono- or dialkylated at N2 on heating with the acetates of primary and secondary amines respectively. A mechanism for these reactions is proposed.

Mitteilung über Hydantoine, Thiohydantoine und Glykocyamidine.

Mitteilung:K. Lempert, Magyar Tudományos Akadémia Kémiai Tudományok Osztályának Közleményei [Ber. Ung. Akad. Wiss., Kl. Chem. Wiss.]12, 59 (1959). — Chem. Reviews59, 667 (1959).  相似文献   

16.
Summary Severala-pyrones have been synthesized and investigated for their in vitro inhibitory activity usinga-chymotrypsin (a-CT), porcine pancreatic elastase, (PPE) and human leukocyte elastase (HLE). 4-Hydroxy-6-undecyl-2H-pyran-2-one4, 4-Hydroxy-6-[(1-butyl)heptyl]-2H-pyran-2-one5 and 4-Methoxy-6-[(1-butyl)heptyl]-2H-pyran-2-one6 were found to be specific inhibitors of HLE. These compounds constitute a promising new class of HLE inhibitors.Acknowledgments. We are grateful to the Petroleum Research Fund of the American Chemical Society (Grant No. 13058-B4), the American Lung Association and the Office of Sponsored Research of Wichita State University for generous financial support of this work. This work was also supported by NHLBIGrant 5PO1HL20994 and the Council for Tobacco Research, USA-Inc. Grant 901B.  相似文献   

17.
The induction of lymphokine-activated killer (LAK) cells from natural killer (NK) lineage cells by interleukin-4 (IL-4) was studied in vitro. Activation of nude mouse spleen cells by IL-4 generated cytotoxic cells, capable of killing NK-sensitive as well as NK-resistant tumor cells. The induction of peak lytic activity was demonstrated after 3 days of culture with IL-4. Surface marker analysis indicated that the majority of precursor cells were aGM1+, Thy1, and the majority of effector cells were aGM1+, Thy1+, suggesting that IL-4 induced LAK cells from nude mouse spleen cells were similar to those from normal mouse spleen cells. The induction of nude mouse LAK cells by IL-4 was partially inhibited by anti-IL-4 or anti-interferon (IFN)-, antibody, and it was further inhibited by the combination of two antibodies, suggesting that IFN-, production was associated with LAK induction of NK lineage cells by IL-4.  相似文献   

18.
Résumé Un système de nomenclature triviale des histamines substituées est proposé. Les positions des substituants sont identifiées sans aucune ambiguité dans la formule IX. Le noyau peut être substitué en position N, 2, N. et 4, et la chaîne latérale en position N, , et .  相似文献   

19.
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   

20.
Metal complex formation by nicotianamine,a possible phytosiderophore   总被引:4,自引:0,他引:4  
Summary The acid dissociation constants of nicotianamine (1) (pK1=6.97, pK2=9.13, pK3=9.75; 0.1 M KClO4, 25°C) and the stability constants for its 11 complexes with bivalent metal ions (log KCu=18.6, log KNi=16.1, log KCo=14.8, log KZn=14.7, log KFe=12.1, log KMn=8.8, log KMg4.5; 0.1 M KClO4, 25°C) were determined using potentiometric titrations in aqueous solution. Fe(III)-nicotianamine complexes were not detected under the same experimental conditions.Part 13 in the series On the normalizing factor for the tomato mutantchloronerva, for part 12 see Ripperger et al.4.  相似文献   

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