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1.
Zhong Z Kotova O Davidescu A Ehrén I Ekberg K Jörnvall H Wahren J Chibalin AV 《Cellular and molecular life sciences : CMLS》2004,61(21):2782-2790
Proinsulin-connecting peptide (C-peptide) exerts physiological effects partially via stimulation of Na+, K+-ATPase. We determined the molecular mechanism by which C-peptide stimulates Na+, K+-ATPase in primary human renal tubular cells (HRTCs). Incubation of the cells with 5 nM human C-peptide at 37°C for 10 min stimulated 86Rb+ uptake by 40% (p<0.01). The carboxy-terminal pentapeptide was found to elicit 57% of the activity of the intact molecule. In parallel with ouabain-sensitive 86Rb+ uptake, C-peptide increased subunit phosphorylation and basolateral membrane (BLM) abundance of the Na+, K+-ATPase 1 and 1 subunits. The increase in BLM abundance of the Na+, K+-ATPase 1 and 1 subunits was accompanied by depletion of 1 and 1 subunits from the endosomal compartments. C-peptide action on Na+, K+-ATPase was ERK1/2-dependent in HRTCs. C-peptide-stimulated Na+, K+-ATPase activation, phosphorylation of 1-subunit and translocation of 1 and 1 subunits to the BLM were abolished by a MEK1/2 inhibitor (20 M PD98059). C-peptide stimulation of 86Rb+ uptake was also abolished by preincubation of HRTCs with an inhibitor of PKC (1 M GF109203X). C-peptide stimulated phosphorylation of human Na+, K+-ATPase subunit on Thr-Pro amino acid motifs, which form specific ERK substrates. In conclusion, C-peptide stimulates sodium pump activity via ERK1/2-induced phosphorylation of Thr residues on the subunit of Na+, K+-ATPase.Received 15 June 2004; received after revision 14 September 2004; accepted 14 September 2004 相似文献
2.
F. V. DeFeudis P. Madtes J. Gervas-Camacho 《Cellular and molecular life sciences : CMLS》1977,33(3):340-342
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 amino acid sequence was compared among the three allelic variants (allozymes) ofsn-glycerol-3-phosphate dehydrogenase inD. virilis, which are detected by one-dimensional electrophoresis. The GPDHf variant was different from the GPDHm by only one substitution of 68-lysine for asparagine; GPDHs differed from GPDHm by substitution of 127-glycine for arginine. No electrophoretically silent substitutions were found in a total of 352 amino acid residues. 相似文献
4.
Summary Na+, K+-adenosinetriphosphatase (Na+, K+-ATPase) activity was decreased in liver plasma membranes from rats in which cholestasis had been induced by i.v. administration of sodium taurolithocholate (5 moles/100 g b. wt). Incubation of liver plasma membranes with taurolithocholate (10–1300 M) caused significant and dose dependent reductions of Na+, K+-ATPase activity at taurolithocholate concentrations above 100 M. These findings lend support to the hypothesis that cholestasis induced by monohydroxy bile acids is at least partially the result of an inhibition of hepatic Na+, K+-ATPase activity.This work was supported by the Swiss National Science Foundation.The authors thank Mr H. Sägesser and Miss B. Schütz for technical assistance. 相似文献
5.
R. Mechoulam Z. Ben Zvi S. Agurell I. M. Nilsson J. L. G. Nilsson H. Edery Y. Grunfeld 《Cellular and molecular life sciences : CMLS》1973,29(10):1193-1195
Zusammenfassung 7-Hydroxy-
6-tetrahydrocannabinol (7-Hydroxy-
6-THC), ein psychotomimetisch aktiver Metabolit des
6-THC, wird von Kaninchen in inaktive
6-THC-7 Säure metabolisiert. Die Synthese dieser Säure wird beschrieben.
The work in Jerusalem was supported by the US National Institute of Mental Health and in Stockholm by the Swedish Medical Research Council. 相似文献
The work in Jerusalem was supported by the US National Institute of Mental Health and in Stockholm by the Swedish Medical Research Council. 相似文献
6.
R. K. Razdan J. F. Howes D. B. Uliss H. C. Dalzell G. R. Handrick W. L. Dewey 《Cellular and molecular life sciences : CMLS》1976,32(4):416-417
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
7.
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
8.
Patricia M. Kralik Beng T. Ho H. R. Matthews 《Cellular and molecular life sciences : CMLS》1976,32(6):723-725
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.
J. T. A. Leuschner D. R. Wing Dr. D. J. Harvey G. A. Brent C. E. Dempsey A. Watts W. D. M. Paton 《Cellular and molecular life sciences : CMLS》1984,40(8):866-868
Summary
1-Tetrahydrocannabinol (
1-THC) has been quantified directly in erythrocyte membranes from drug-treated mice using gas chromatography/mass spectrometry. Concentrations of approximately 6 ng
1-THC/mg membrane protein (10–5 M) were found when effects of the drug on behavior were prevalent. At these concentrations the drug produced a decrease in membrane order as measured by ESR.This work was supported by grants from the Medical Research Council, the Wellcome Trust and the E. P. Abraham Cephalosporin Trust 相似文献
10.
R. R. Erttmann 《Cellular and molecular life sciences : CMLS》1978,34(12):1620-1621
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
11.
Summary The effect of norepinephrine on fatty acid synthesis (3H2O incorporation into fatty acids), on fatty acid oxidation to CO2 and on ketogenesis was studied in isolated hepatocytes of fed rats. After incubation with norepinephrine (50 M), lipogenesis was lower (5.7±1.1 nmoles3H2O incorporated into fatty acids/mg dry weight/30 min) than in controls (7.5±1.7; n=6, p<0.02). In contrast, (1-14C) palmitate conversion into total ketone bodies was increased to 10.9±1.8 nmoles/mg/30 min with norepinephrine, vs 8.5±1.6 in controls (p<0.05), and more (1-14C) palmitate was converted to14CO2 with norepinephrine than in controls (1.48±0.10 nmoles/mg/30 min vs 1.06±0.11, p<0.05). The inhibitory effect of norepinephrine on lipogenesis was abolished by addition of the 1-receptor blocker prazosin, but not by 2 or -blockers. The results demonstrate that the ketogenic effect of norepinephrine is coupled with an inhibitory effect on lipogenesis which may be explained by diminished activity of acetyl-CoA carboxylase, diminished formation of malonyl-CoA and decreased activity of carnitine palmitoyl transferase I. 相似文献
12.
Fu WX Gong SY Qian XP Li Y Zhu ML Dong XY Li Y Chen WF 《Cellular and molecular life sciences : CMLS》2004,61(15):1935-1945
Mouse platelet basic protein (CXCL7/mPBP) was cloned from thymic stromal cells and further identification
indicated that it was expressed in thymic monocytes/macrophages (Mo/Ms). Recombinant mPBP was
chemoattractive for target cells of polymorphonuclear leucocytes, peritoneal Mo/Ms and splenic lymphocytes
with distinct potencies. CXCR2 was identified to be a cognate receptor for mPBP. Mouse thymocyte subsets of
CD4-CD8- double-negative (DN),
CD4+CD8+ double-positive (DP),
CD4+CD8- single-positive (CD4SP)
and CD4-CD8+ single-positive (CD8SP) expressed cell surface
CXCR2 with different positive percentages and expression levels. mPBP was chemoattractive for thymocyte subsets
with the potency order DN>DP> CD8SP>CD4SP, consistent with the levels of CXCR2 expressed on the
respective cells. Thus, mPBP in thymus is functionally redundant with chemokine CXCL12/ SDF-1. Moreover, our
finding that thymic Mo/Ms can produce mPBP implies that they may have other functions apart from acting as
scavengers in thymus.Received 25 March 2004; received after revision 10 May 2004; accepted 8 June 2004 相似文献
13.
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
14.
Y. Kaneko Y. Imai F. Matsuzaki Y. Endo T. Oda 《Cellular and molecular life sciences : CMLS》1979,35(12):1660-1661
Summary Epidermal growth factor stimulated both [3H]thymidine uptake and proliferation of rat AH66 hepatoma cells. However, the increase in cell number was not accompanied by a proportional increase in the levels of -fetoprotein of the culture media. The effects of EGF on the cell proliferation were antagonized by N6, O2-dibutyryl cAMP. 相似文献
15.
J. Tadanier 《Cellular and molecular life sciences : CMLS》1965,21(10):563-565
Zusammenfassung Die Existenz von zwei verschiedenen isomeren Homoallylkationen in der Umlagerung von Steroid-
5-19-Methansulfonsäure-Estern zu 5, 19-cyclo-6-hydroxylierten Steroiden und deren Umlagerung zu
5(10)-B-homo-7-hydroxylierten Steroiden wurde bewiesen, und eine neue Art der Homoallylumlagerung eines
5(10)-B-homo-7-hydroxylierten Steroids zum 5, 6-Methano-9-en und zum 5, 6-Methano-10-ol wurde beobachtet.
This material was presented at theSymposium on Steroids Made Through Intramolecular Functionalization on the C 18-and C 19-Methyl Groups, at the 149th meeting of the American Chemical Society in Detroit (Michigan), on April 7, 1965. 相似文献
This material was presented at theSymposium on Steroids Made Through Intramolecular Functionalization on the C 18-and C 19-Methyl Groups, at the 149th meeting of the American Chemical Society in Detroit (Michigan), on April 7, 1965. 相似文献
16.
I. J. Miller N. K. McCallum C. M. Kirk B. M. Peake 《Cellular and molecular life sciences : CMLS》1982,38(2):230-231
Summary The free radical oxidation of 1 and 6-tetrahydrocannabinol has been examined by spin trapping techniques and intermediates that would lead to cannabinol have been trapped. The 1st step in the oxidation of 1-THC involves the removal of 3-H, while for 6-THC, either 2-H or 5-H. Intermediates were isolated which could be pyrolysed to the diene and cannabinol. 相似文献
17.
Wang QY Guo P Duan LL Shen ZH Chen HL 《Cellular and molecular life sciences : CMLS》2005,62(2):171-178
After the transfection of -1,3-fucosyltransferase (FucT)-VII cDNA into H7721 human hepatocarcinoma cells, the protein expression of some cyclins, cyclin-dependent kinases (CDKs) and cyclin-dependent kinase inhibitors (CDIs) p16INK4 and p21waf1/Cip1 were unchanged. However, CDI p27Kip1 protein, both the total amount and the amount that bound to CDK2, but not its mRNA, was significantly reduced. The de-inhibited CDK2 stimulated the phosphorylation of retinoblastoma (Rb) protein and facilitated the G1/S transition and growth rate of the cells. The decrease of p27Kip1 protein, the increase of CDK2 activity and Rb phosphorylation, as well as the cell growth and percentage of S phase cells were correlated to the increased amount of cell surface sialyl Lewis X (SLex) antigen in cells with different -1,3-FucT-VII expression. The reduction in p27Kip1 and the difference in its expression among different transfected cells were blocked by the SLex antibody KM93 in a dose-dependent manner, indicating that p27Kip1 expression was influenced by -1,3-FucT-VII and its product SLex. The MEK/MAPK signaling pathway was more important than the PI-3K pathway in the regulation of p27Kip1 expression.Received 5 August 2004; received after revision 25 October 2004; accepted 11 November 2005 相似文献
18.
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
19.
R. P. Duffley G. Lambert H. C. Dalzell R. K. Razdan 《Cellular and molecular life sciences : CMLS》1981,37(9):931-932
Summary The synthesis of (±)-211-dihydroxy-
9-THC, a difunctionalized metabolite of
9-THC, is presented.Acknowledgment. This work was carried out with the support of NIDA Grant No. DA 00574. We are grateful to Mr. J. Coe for assistance with some of the experiments. 相似文献
20.
Summary Rat liver microsomes, NADPH-regenerating system, and 1, 2-3H-testosterone have been incubated in vitro. The loss of tritium from the steroid, associated with aromatization of testosterone, was linear with time for 20 min and required NADPH. Pre-treatment of the rats with thioacetamide raised the liberation of tritium from 1, 2-3H-testosterone. The results suggest that liver damage by thioacetamide in rats may give rise to increased aromatization of testosterone. 相似文献