Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 17 de 17
Filter
1.
Rev Sci Instrum ; 85(11): 11D818, 2014 Nov.
Article in English | MEDLINE | ID: mdl-25430231

ABSTRACT

An overview of the diagnostics which are essential for the first operational phase of Wendelstein 7-X and the set of diagnostics expected to be ready for operation at this time are presented. The ongoing investigations of how to cope with high levels of stray Electron Cyclotron Resonance Heating (ECRH) radiation in the ultraviolet (UV)/visible/infrared (IR) optical diagnostics are described.

2.
Z Geburtshilfe Neonatol ; 217(4): 123-9, 2013 Aug.
Article in German | MEDLINE | ID: mdl-23982938

ABSTRACT

Tobacco consumption is a major public health threat. Midwives can contribute to the reduction of tobacco use among pregnant women and young families. It can be assumed that personal smoking behaviour and knowledge of harmful effects influences counselling activities. The aim of this study was to assess smoking status, nicotine dependency and the will to change of midwifery students in german-speaking countries. Broad data on this population is not available so far. In 2010, a self-administered questionnaire survey was conducted among Austrian, German and Swiss midwifery schools. Sociodemographic characteristics, smoking habits, personal attitudes towards smoking, knowledge of cessation strategies, perceived self-efficacy and competence to counsel pregnant women regarding their smoking habits of midwifery trainees were examined. 1 126 students and 38 teaching midwives answered this questionnaire (RR=61.8%). 22.7% are daily or occasional smokers. 6.8% have to be considered as medium and heavy smokers. 98.1% consider cessation counselling for pregnant and breast-feeding women as a midwife's task, while 76.5% feel competent enough to do so. 75.5% rate cessation counselling through midwives as effective stop-smoking procedures compared to blurry knowledge on related health risks and effective stop-smoking strategies. The self-reported smoking prevalence is considerably lower than in previous studies and other populations. Knowledge of harmful effects and of effective treatment options needs improvement. Counselling competence needs to be included in a broader way in midwifery curricula.


Subject(s)
Directive Counseling/statistics & numerical data , Midwifery/education , Midwifery/statistics & numerical data , Professional Competence/statistics & numerical data , Smoking Cessation/statistics & numerical data , Smoking Prevention , Smoking/epidemiology , Attitude of Health Personnel , Attitude to Health , Female , Germany/epidemiology , Health Promotion/statistics & numerical data , Humans , Male , Patient Education as Topic/statistics & numerical data , Smoking/psychology , Smoking Cessation/psychology , Students/psychology , Students/statistics & numerical data , Students, Health Occupations/psychology , Students, Health Occupations/statistics & numerical data , Young Adult
3.
Rev Sci Instrum ; 83(10): 10D730, 2012 Oct.
Article in English | MEDLINE | ID: mdl-23126902

ABSTRACT

The critical issues in the development of diagnostics, which need to work robust and reliable under quasi-steady state conditions for the discharge durations of 30 min and which cannot be maintained throughout the one week duration of each operation phase of the Wendelstein 7-X stellarator, are being discussed.

4.
Thromb Haemost ; 107(4): 769-74, 2012 Apr.
Article in English | MEDLINE | ID: mdl-22318706

ABSTRACT

Erythropoietin improves myocardial function and enhances re-endothelialisation. Aim of this study was to analyse progenitor cell mobilisation and restenosis in patients from the Regeneration of Vital Myocardium in ST-Segment Elevation Myocardial Infarction by Erythropoietin (REVIVAL-3) study. Patients with STEMI undergoing percutaneous coronary intervention (PCI) were randomly assigned to Epoetin beta (EPO) (n=68) or placebo (n=70). Drug-eluting stents (DES) were utilised in 93% of patients receiving EPO and in 95% of patients receiving placebo (p=0.83). Serial venous blood samples were drawn; CD133+ progenitor cells were quantified by four-colour flow cytometry and cytokines interleukin (IL)-1ß, IL-6, IL-8, IL-10, IL-12 and tumour necrosis factor (TNF) alpha were analysed by cytometric bead array. Forty-eight hours after PCI a significant increase in CD133+ progenitor cells was observed in the EPO group. Yet, no differences in plasma cytokines were found. Quantitative coronary angiography after six months revealed an increase in segment diameter stenosis in the EPO group (32 ± 19% vs. 26 ± 14%, p=0.046). However, this increase in neointima generation was not associated with progenitor cell mobilisation. EPO in patients with STEMI treated with PCI is associated with an increase in diameter stenosis that is not associated with circulating progenitor cells.


Subject(s)
Erythropoietin/metabolism , Interleukins/metabolism , Myocardial Infarction/metabolism , Stem Cells/cytology , Angiography/methods , Cytokines/metabolism , Drug-Eluting Stents , Erythropoietin/therapeutic use , Flow Cytometry/methods , Hematopoietic Stem Cell Mobilization , Humans , Inflammation , Placebos , Recombinant Proteins/therapeutic use , Time Factors , Treatment Outcome
5.
Rev Sci Instrum ; 81(10): 10E133, 2010 Oct.
Article in English | MEDLINE | ID: mdl-21033995

ABSTRACT

The status of the diagnostic developments for the quasistationary operable stellarator Wendelstein 7-X (maximum pulse length of 30 min at 10 MW ECRH heating at 140 GHz) will be reported on. Significant emphasis is being given to the issue of ECRH stray radiation shielding of in-vessel diagnostic components, which will be critical at high density operation requiring O2 and OXB heating.

6.
Rev Sci Instrum ; 79(10): 10F337, 2008 Oct.
Article in English | MEDLINE | ID: mdl-19044644

ABSTRACT

The stellarator Wendelstein 7-X will allow for quasicontinuous operation with the duration only being limited to two 30 min discharges per day, at a continuous heating power of 10 MW electron cyclotron resonance heating (ECRH) at 140 GHz, by the capacity of the cooling water reservoir. This will result in high thermal loads on all plasma facing components of 50-100 kW/m(2) from radiation alone and of up to about 500 kW/m(2) on components additionally exposed to convective loads. In high density scenarios toroidally varying ECRH stray radiation levels of 50-200 kW/m(2) need to be coped with, requiring careful material selection and different shielding and hardening techniques. Furthermore, a gradual buildup of coatings on plasma facing optical components, which without any measures being taken, would lead to high transmission losses already within a few days of long pulse operation (equivalent to about 1 year of operation in pulsed devices like JET or ASDEX-upgrade) and therefore needs to be prevented as much as possible. In addition in situ cleaning as well as absolute calibration techniques need to be developed for all plasma facing optical systems. Here we report about some of our efforts to find, for various types of diagnostics, ways to cope with these adverse effects. Moreover, we give a few examples for individual diagnostic specific issues with respect to quasicontinuous operation, such as the development of a special integrator for the magnetic diagnostics as well as special interferometer types which can cope with unavoidable vibrations and slow path length changes due to, e.g., thermal expansion of the plasma vessel.

7.
Pharmazie ; 63(9): 667-70, 2008 Sep.
Article in English | MEDLINE | ID: mdl-18819520

ABSTRACT

The purpose of this study was to evaluate the toxicity of the oligonucleotide/cationic nanoemulsion complexes on Hep G2 cells through MTT assay. Complexes exhibit droplet size, zeta potential and viscosity of approximately 270 nm, +50mV, and 1.0 cP. Different parameters which may have an influence on toxicity results obtained by MTT assay, i.e. cells number, concentration of MTT reagent and the addition of Soerensen's glycine buffer were first evaluated. In the optimized conditions (1 x 10(4) cells and 0.5 mg/mL MTT), the overall results showed that the addition of increasing amounts of complexes (or nanoemulsions) lead to a progressive toxicity on cells attributed to the presence of the cationic lipid stearylamine in the formulations, whatever the medias's pH is. The IC50 was approximately 200 microg/ml. Such results open interesting perspectives on the use of these nanoemulsions as oligonucleotide delivery systems for Hep G2 cells.


Subject(s)
Cations/toxicity , Coloring Agents/toxicity , Oligonucleotides/toxicity , Tetrazolium Salts/toxicity , Thiazoles/toxicity , Cell Line, Tumor , Cell Survival/drug effects , Chemical Phenomena , Chemistry, Pharmaceutical , Chemistry, Physical , Drug Screening Assays, Antitumor , Emulsions , Humans , Nanoparticles , Viscosity
8.
Int Endod J ; 33(6): 483-93, 2000 Nov.
Article in English | MEDLINE | ID: mdl-11307251

ABSTRACT

AIM: To assess the reliability of routine single radiographs in the diagnosis of inflammatory apical root resorption by correlating the radiographic and histological findings. METHODOLOGY: The material comprised serial and step serial sections of plastic-embedded root-apices with attached apical periodontitis lesions that were prepared for a previous study and the diagnostic radiographs. The histological sections of 114 specimens were analysed by light microscopy and categorized into three groups: (i) those without any resorption (0); (ii) those with moderate resorption (+); and (iii) those with severe resorption (+ +). The radiographs were examined by a separate examiner and graded with a similar categorization of no resorption (0); moderate (+); and severe (+ +) apical resorption. RESULTS: Radiographically, 19% of the teeth were diagnosed as having apical inflammatory root resorption, whereas histologically, 81% of the teeth revealed apical inflammatory root resorption. A correlative radiographic and histological assessment (n = 104) revealed a coincidence of diagnosis in 7% of the specimens and noncoincidence of diagnosis in 76% of the specimens. CONCLUSIONS: The results indicate that routine single radiographs are not sufficiently accurate or sensitive to consistently diagnose apical root resorptive defects developing as a consequence of apical periodontitis.


Subject(s)
Periapical Periodontitis/diagnostic imaging , Root Resorption/diagnostic imaging , Tooth Apex/diagnostic imaging , Dental Cementum/pathology , Dentin/pathology , Humans , Observer Variation , Periapical Periodontitis/pathology , Plastic Embedding , Radiography, Bitewing , Radiography, Panoramic , Root Resorption/classification , Root Resorption/pathology , Tooth Apex/pathology
9.
Biochim Biophys Acta ; 1126(1): 105-13, 1992 Jun 05.
Article in English | MEDLINE | ID: mdl-1606170

ABSTRACT

High density lipoproteins (HDL) consist of a mixture of chemically and functionally distinct families of particles defined by their characteristic apolipoprotein (Apo) composition. The two major lipoprotein families are lipoprotein A-I (LP-A-I) and lipoprotein A-I:A-II (LP-A-I:A-II). This study describes the isolation of a third minor HDL family of particles referred to as lipoprotein A-II (LP-A-II) because it lacks ApoA-I and contains ApoA-II as its main or sole apolipoprotein constituent. Because ApoA-II is an integral protein constituent of three distinct lipoprotein families (LP-A-I:A-II, LP-A-II: B:C:D:E and LP-A-II), LP-A-II particles were isolated from whole plasma by sequential immunoaffinity chromatography on immunosorbers with antisera to ApoA-II, ApoB and ApoA-I, respectively. In normolipidemic subjects, the concentration of LP-A-II particles, based on ApoA-II content, is 4-18 mg/dl accounting for 5-20% of the total ApoA-II not associated with ApoB-containing lipoproteins. The lipid composition of LP-A-II particles is characterized by low percentage of triglycerides and cholesterol esters and a high percentage of phospholipids in comparison with lipid composition of LP-A-I and LP-A-II: A-II. The major part of LP-A-II particles contain ApoA-II as the sole apolipoprotein constituent; however, small subsets of LP-A-II particles may also contain ApoD and other minor apolipoproteins. The lipid/protein ratio of LP-A-II is higher than those of LP-A-I and LP-A-I:A-II. In homozygous ApoA-I and ApoA-I/ApoC-III deficiencies, LP-A-II particles are the only ApoA-containing high density lipoprotein with levels found to be within the same range (7-13 mg/dl) as those of normolipidemic subjects. However, in contrast to normal LP-A-II, their lipid composition is characterized by higher percentages of triglycerides and cholesterol esters and a lower percentage of phospholipids and their apolipoprotein composition by the presence of ApoC-peptides and ApoE in addition to ApoA-II and ApoD. These results show that LP-A-II particles are a minor HDL family and suggest that, in the absence of ApoA-I-containing lipoproteins, they become an efficient acceptor/donor of ApoC-peptides and ApoE required for a normal metabolism of triglyceride-rich lipoproteins. Their other possible functional roles in lipid transport remain to be established in future experiments.


Subject(s)
Apolipoprotein A-II/isolation & purification , Apolipoprotein A-I/deficiency , Apolipoprotein A-II/chemistry , Apolipoprotein A-II/physiology , Apolipoproteins/analysis , Humans , Lipids/analysis
10.
J Lipid Res ; 32(10): 1587-99, 1991 Oct.
Article in English | MEDLINE | ID: mdl-1797940

ABSTRACT

This study describes a variant of familial apoA-I deficiency associated with a moderate risk for premature coronary artery disease. The proband, a 25-year-old man of Philippine origin, and his 62-year-old maternal aunt had peripheral corneal opacification, xanthelasma, and planar xanthoma; the aunt had coronary artery bypass surgery at 61 years of age. Proband's parents and three brothers were asymptomatic and apparently healthy. The characteristic apolipoprotein features of affected patients were the immunochemically and chemically undetectable apoA-I, reduced levels of apoA-II, apoC-II, apoC-III, and apoD, and normal levels of apoB and apoE; except for negligible levels of high density lipoprotein (HDL)-cholesterol (2-3 mg/dl), their plasma lipid profile was normal. The apoA-I levels in all five unaffected relatives were more than one SD below the normal mean values for their age and sex; the HDL-cholesterol levels of proband's unaffected brothers were below the 10th percentile of normal control values. Patient's very low density lipoprotein (VLDL), low density lipoprotein (LDL), and HDL contained 1.4, 80.4, and 18.1%, whereas those of control subjects contained 2.7, 28.8, and 68.1% of the total apolipoprotein mass, respectively. In unaffected relatives, the levels of LP-A-I, but not LP-A-I:A-II, were significantly lower than in controls. Neither of the two patients had detectable concentrations of LP-A-I or LP-A-I:A-II. Their HDL only consisted of LP-A-II particles, the levels of which (7-13 mg/dl) were similar to those of unaffected relatives or controls. There was no difference in the lipid composition of LP-A-II between patients and their relatives. However, LP-A-II from patients contained substantial amounts of apoC-peptides and apoE (0.40-0.98 mg/mg apoA-II), whereas those from unaffected relatives were free of these minor apolipoproteins. In patients, among all four major apoB-containing lipoproteins, only the levels of LP-B and LP-B:C were slightly higher than those in controls. Results of this study suggest a genetic cause for this variant of apoA-I deficiency characterized most probably by autosomal recessive inheritance. It appears that patients are likely to be homozygous for a gene present in single dose in the parents and brothers of the affected proband.(ABSTRACT TRUNCATED AT 400 WORDS)


Subject(s)
Apolipoprotein A-II/metabolism , Apolipoprotein A-I/deficiency , Apolipoproteins A/metabolism , Apolipoproteins B/metabolism , Histiocytosis, Non-Langerhans-Cell/blood , Adult , Corneal Opacity/complications , Coronary Disease/complications , Female , Histiocytosis, Non-Langerhans-Cell/complications , Humans , Isoelectric Focusing , Lipoproteins/blood , Lipoproteins/chemistry , Male , Middle Aged , Pedigree , Risk Factors
11.
J Steroid Biochem Mol Biol ; 37(2): 261-7, 1990 Oct.
Article in English | MEDLINE | ID: mdl-2268558

ABSTRACT

Several new 4,19-substituted steroids and previously synthesized corticosteroids were assayed for affinity to type 1 receptors in human mononuclear leukocytes. 11 beta,19-epoxy-4,21-dihydroxypregn-4-ene-3,20-dione (2) was hydrogenated with Pd-C to yield a mixture of all four dihydro derivatives 5, accompanied by 4,21-diacetoxy-11 beta,19-epoxy-3-hydroxypregnan-20-one (6) and 21-acetoxy-11 beta,19-epoxy-4-hydroxypregnane-3,20-dione (7). With hot acetic + p-toluenesulfonic acid 5 underwent rearrangement to 21-acetoxy-11 beta,19-epoxypregn-5-ene-4,20-dione (8) Pd-C hydrogenation of 3,21-diacetoxy-5 beta,19-cyclopregna-2,9(11)-diene-4,20-dione (10) gave 3,21-diacetoxy-5 beta,19-cyclopregn-5-ene-4,20-dione (11) and the 9,11-dihydro derivative of the latter. Treatment of 10 with warm HCl furnished 19-chloro-4,21-dihydroxypregna-4,9(11)-diene-3,20-dione (13). Pd-C hydrogenation of its diacetate 14 afforded the 4,5-dihydro derivative 18, 19-chloro-21-acetoxypregn-9(11)-en-20-one (15), its 4-acetoxy derivative 16 and the 3,4-diacetoxy derivative 17. When tested in a radioreceptor assay in human mononuclear leukocytes the synthesized compounds showed only low relative binding affinities (RBA) to type 1 receptor, the highest being 0.72% for 13 (aldosterone = 100%). For comparison, other RBA in this system were: 19-noraldosterone, 20%; 18-deoxyaldosterone, 5.8%; 18-deoxy-19-noraldosterone, 4.7%; 18,21-anhydroaldosterone, 0.37%; 17-isoaldosterone, 7.6% and apoaldosterone, 4.3%


Subject(s)
Desoxycorticosterone/analogs & derivatives , Desoxycorticosterone/chemical synthesis , Leukocytes, Mononuclear/metabolism , Receptors, Glucocorticoid/metabolism , Aldosterone/blood , Binding, Competitive , Desoxycorticosterone/chemistry , Desoxycorticosterone/pharmacology , Humans , Indicators and Reagents , Magnetic Resonance Spectroscopy , Mass Spectrometry , Molecular Structure , Radioligand Assay , Receptors, Glucocorticoid/drug effects , Structure-Activity Relationship , Tritium
12.
J Steroid Biochem ; 34(1-6): 331-2, 1989.
Article in English | MEDLINE | ID: mdl-2626028

ABSTRACT

We were able to show that spontaneously hypertensive stroke-prone rats (SHR-SP) have a lower number of glucocorticoid receptors (P-value is of borderline significance, 0.01 greater than P less than 0.05) with a highly significant lower Kd (P less than 0.0005), i.e higher affinity in their mononuclear leukocytes, compared to normotensive Wistar-Kyoto rats (WKY). The plasma levels of corticosterone, aldosterone and 18-hydroxycorticosterone of the two strains do not differ.


Subject(s)
Hypertension/blood , Monocytes/metabolism , Receptors, Glucocorticoid/metabolism , 18-Hydroxycorticosterone/blood , Aldosterone/blood , Animals , Corticosterone/blood , Female , Kinetics , Rats , Rats, Inbred SHR , Rats, Inbred WKY , Species Specificity
13.
J Biol Chem ; 262(29): 14154-7, 1987 Oct 15.
Article in English | MEDLINE | ID: mdl-2820996

ABSTRACT

Addition of the uncoupler and protonophore carbonyl cyanide m-chlorophenylhydrazone (CCCP) to starved yeast cells starts endogenous alcoholic fermentation lasting about 20 min. Hexose 6-phosphates, fructose 2,6-bisphosphate, and pyruvate accumulate in less than 2 min after addition of CCCP from almost zero concentration to concentrations which correspond to 1/5-1/10 of the steady-state concentrations during fermentation of glucose. CCCP immediately causes a decrease of the intracellular cytosolic pH from 6.9 to 6.4. This change activates adenylate cyclase (Purwin, C., Nicolay, K., Scheffers, W.A., and Holzer, H. (1986) J. Biol. Chem. 261, 8744-8749) and leads to the previously observed transient increase of cyclic AMP. It is shown here that the following enzymes known from in vitro experiments to be activated by cyclic AMP-dependent phosphorylation are activated in the CCCP-treated starved yeast cells in vivo: glycogen phosphorylase, trehalase (pH 7), 6-phosphofructo-2-kinase. The activation of 6-phosphofructo-2-kinase leads to an accumulation of fructose 2,6-bisphosphate, which is known from in vitro experiments to activate 6-phosphofructo-1-kinase and to inhibit fructose-1,6-bisphosphatase. All effects observed in the intact yeast cells fit with the idea that the CCCP-initiated activation of adenylate cyclase leads to a sequence of events which by protein phosphorylation and allosteric effects initiates endogenous alcoholic fermentation.


Subject(s)
Carbonyl Cyanide m-Chlorophenyl Hydrazone/pharmacology , Nitriles/pharmacology , Saccharomyces cerevisiae/metabolism , Cyclic AMP/metabolism , Cytosol/metabolism , Fermentation , Hydrogen-Ion Concentration , Magnetic Resonance Spectroscopy/methods , Saccharomyces cerevisiae/drug effects
14.
Eur J Biochem ; 165(3): 543-5, 1987 Jun 15.
Article in English | MEDLINE | ID: mdl-3036508

ABSTRACT

Using comparative ion-exchange chromatography on Dowex 1X4, the product of dephosphorylation of fructose 2,6-bisphosphate with purified yeast fructose-2,6-bisphosphate 6-phosphohydrolase, was shown to be identical to the furanose form of fructose 2-phosphate prepared by chemical synthesis according to Pontis and Fischer [Biochem. J. 89, 452-459 (1963)]. As expected for the furanose form of fructose 2-phosphate, the enzymatically formed product consumes 1 mol periodate/mol fructose 2-phosphate, whereas the chemically synthesized pyranose form consumes 2 mol periodate/mol. In addition, it is shown that the enzymatic product behaves identically to the furanose, not the pyranose, form of fructose 2-phosphate in hydrolysis of the ester bond at pH 4 and 37 degrees C, as described previously for the chemically synthesized compounds [Pontis and Fischer (1963) vide supra].


Subject(s)
Fructosediphosphates/metabolism , Fructosephosphates/biosynthesis , Hexosediphosphates/metabolism , Chromatography, Ion Exchange , Hydrolysis , Phosphoric Monoester Hydrolases/metabolism , Saccharomyces cerevisiae/enzymology
15.
Eur J Biochem ; 164(1): 27-30, 1987 Apr 01.
Article in English | MEDLINE | ID: mdl-2951255

ABSTRACT

A fructose-2,6-bisphosphate dephosphorylating enzyme was 3000-fold purified to electrophoretic homogeneity from Saccharomyces cerevisiae. Half-maximal activity was obtained at pH 6.0 with 6 microM fructose 2,6-bisphosphate and 0.15 mM Mg2+. On incubation for 90 min with fructose 2,6-bisphosphate, about 80% of the substrate appears with an almost linear time dependence as fructose. In the first 30 min a substance accumulates to about 40% of the consumed fructose 2,6-bisphosphate which forms free fructose on mild acid treatment. Formation of fructose 6-phosphate was negligible. The mild-acid-labile intermediate was identified as fructose 2-phosphate by comparative ion-exchange chromatography with authentic fructose 2-phosphate synthesized from fructose 1-phosphate [Pontis, H.G. & Fischer, C.L. (1963) Biochem. J. 89, 452-459]. The data suggest the reaction sequence fructose 2,6-bisphosphate----fructose 2-phosphate----fructose. The designation fructose-2,6-bisphosphate 6-phosphohydrolase is proposed for the enzyme described here.


Subject(s)
Fructosediphosphates/metabolism , Fructosephosphates/metabolism , Hexosediphosphates/metabolism , Phosphofructokinase-1/metabolism , Saccharomyces cerevisiae/enzymology , Alkaline Phosphatase/metabolism , Fructose/metabolism , Hydrogen-Ion Concentration , Kinetics , Magnesium/metabolism , Time Factors
16.
Naunyn Schmiedebergs Arch Pharmacol ; 334(1): 1-9, 1986 Sep.
Article in English | MEDLINE | ID: mdl-2431325

ABSTRACT

We have studied the accumulation of inositol phosphates (InsP) due to depolarization. A particulate preparation of rat brain was introduced to rule out transmitter activated mechanisms and to allow free access for drugs of high molecular weights. Potassium depolarization doubled InsP within a few minutes. InsP accumulation depended on time and K+ concentration, and was affected neither by tetrodotoxin nor by atropine. Radioactive metabolites co-eluted with inositol mono-phosphate and inositol bis-phosphate, whereas only minor amounts appeared with inositol tris-phosphate. The content in phosphatidylinositols was decreased. No evidence was found for the involvement of a neurotransmitter. Sea anemone toxin II (around 1 mumol/l), which keeps the Na+-channels open, promoted the InsP accumulation in an atropine-resistant manner. Tetrodotoxin prevented it when given before, and inhibited it when given after initiation by sea anemone toxin II. Moreover the K+ channel blockers 4-aminopyridine, dendrotoxin and tetraethylammonium all caused InsP accumulation. Palytoxin was by far the most potent promoter of InsP accumulation with a detection limit below 10 pmol/l, and displayed a unique bell-shaped concentration-effect correlation. Ouabain (3 mumol/l and above) also elicited the InsP accumulation. The response to carbachol was not only inhibited completely by atropine, but also partially (more than 50%) by tetrodotoxin, which indicates the involvement of voltage-dependent sodium channels in the receptor-triggered InsP accumulation. Thus independent of the causative agent, depolarization promotes an InsP accumulation. We conclude that degradation of phosphatidylinositols is mediated not only by receptor occupation but also by a positive shift in membrane voltage.


Subject(s)
Acrylamides , Brain/metabolism , Inositol Phosphates/biosynthesis , Neuromuscular Depolarizing Agents/pharmacology , Sugar Phosphates/biosynthesis , Animals , Brain/drug effects , Calcium/physiology , Cnidarian Venoms/pharmacology , In Vitro Techniques , Ion Channels/drug effects , Male , Ouabain/pharmacology , Potassium/pharmacology , Rats , Toxins, Biological/pharmacology
SELECTION OF CITATIONS
SEARCH DETAIL
...