Action of DL-19-nor-D-homotestosterone on the interferon system and on synthesis of total cell protein in tissue culture

1969 ◽  
Vol 67 (2) ◽  
pp. 171-173
Author(s):  
N. A. Zeitlenok ◽  
V. M. Roikhel' ◽  
E. A. Gorbachkova
Keyword(s):  
Tissue Culture ◽  
Total Cell ◽  
Cell Protein ◽  
Total Cell Protein ◽  
Interferon System

Contraction regulates myosin synthesis and myosin content of cultured heart cells

1985 ◽  
Vol 249 (4) ◽  
pp. H763-H769
Author(s):  
P. McDermott ◽  
M. Daood ◽  
I. Klein
Keyword(s):  
Protein Synthesis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Total Cell ◽  
Neonatal Rat ◽  
Cell Protein ◽  
Heart Cells ◽  
Culture Dish ◽  
Total Cell Protein ◽  
Cultured Heart Cells

Cultured neonatal rat heart cells are a useful model for studying the regulation of myocyte growth. The myosin content of heart cells increases between days 1 and 4 in culture. To determine if contraction per se can regulate myocyte growth, myosin content and protein synthesis were compared in spontaneously contracting and noncontracting cultured heart cells. Myosin content, assayed as the total myosin ATPase activity per culture dish, was significantly increased in contracting cells after 3, 4, and 5 days in culture. Protein synthesis was measured by incorporation of [14C]lysine into total cell protein and into sodium dodecyl sulfate-polyacrylamide gel electrophoresis resolved myosin. Contraction stimulated both total cell protein content and protein synthesis by day 3 in culture. Compared with heart cells arrested with 50 mM KCl, myosin synthesis was significantly increased by 96, 112, and 46% at days 2, 3, and 4, respectively. Similar results were observed when myosin content and protein synthesis in contracting myocytes were compared with cells arrested with either 25 mM KCl or 10(-5) M verapamil. The present studies suggest that contraction increases the myosin content in cultured heart cells and that this increase is mediated via a stimulation of myosin synthesis in association with cell growth.

Sub-cellular fractionation ofTrypanosoma brucei. Isolation and characterization of plasma membranes

Parasitology ◽  
1980 ◽  
Vol 80 (3) ◽  
pp. 507-524 ◽  
Author(s):  
Luciana Rovis ◽  
Steinunn Baekkeskov
Keyword(s):  
High Speed ◽  
Plasma Membranes ◽  
Specific Activity ◽  
Total Cell ◽  
Molar Ratio ◽  
Cell Protein ◽  
Phospholipid Content ◽  
Total Cell Protein ◽  
Isolation And Characterization ◽  
Enzymatic Markers

SummaryA procedure is described for the isolation of sub-cellular fractions from bloodstream forms ofTrypanosoma brucei. The method leaves intact most of the nuclei, mitochondria and microbodies. All the fractions have been chemically characterized and tested for 10 enzymatic markers. About 5% of total cell protein was isolated as a microsomal fraction containing mostly plasma membranes and endoplasmic reticulum vesicles. Plasma membranes were purified by high-speed centrifugation on magnesium-containing Dextran, and on linear sucrose-density gradients. The yield of membranes was approximately 0·3% of the total cell protein. The purified material had a sucrose density of 1·14 g/cm3and consisted of smooth vesicles. Specific activity of the membrane markers Na+, K+, ouabain-sensitive ATPase and adenylate cyclase were 26-and 20-fold higher, respectively, than in total cells. Neither DNA nor RNA was detected. The sum of the cholesterol and phospholipid content was 0·99 mg/mg protein. The cholesterol/phospholipid molar ratio was 1 : 2.

Cytophotometric assessment of Feulgen-DNA and coomassie-total cell protein in adrenocortical fasciculata cells of noise-exposed wister rats

1991 ◽  
Vol 9 (4) ◽  
pp. 287-292
Author(s):  
D. U. Ballough ◽  
G. P. Ballough ◽  
J. A. Strauss ◽  
M. J. Durkot ◽  
A. Anthony
Keyword(s):  
Total Cell ◽  
Cell Protein ◽  
Total Cell Protein

Skeletal muscle growth is stimulated by intermittent stretch-relaxation in tissue culture

1989 ◽  
Vol 256 (3) ◽  
pp. C674-C682 ◽  
Author(s):  
H. H. Vandenburgh ◽  
S. Hatfaludy ◽  
P. Karlisch ◽  
J. Shansky
Keyword(s):  
Creatine Kinase ◽  
Protein Synthesis ◽  
Cell Growth ◽  
Mechanical Stimulation ◽  
Basal Medium ◽  
Total Cell ◽  
Mechanical Activity ◽  
Cell Protein ◽  
Cell Hyperplasia ◽  
Total Cell Protein

Avian pectoralis muscle cells differentiated in vitro are mechanically stimulated by repetitive stretch-relaxation of the cell's substratum using a computerized mechanical cell stimulator device. Initiation of mechanical stimulation increases the efflux of creatine kinase from the cells during the first 8-10 h of activity, but the efflux rate returns to control levels after this time period. Decreased total cell protein content accompanies the temporary elevation of creatine kinase efflux. With continued mechanical stimulation for 48-72 h, total cell protein loss recovers and significantly increases in medium supplemented with serum and embryo extract. Myotube diameters increase and cell hyperplasia occurs in the stimulated cultures. In basal medium without supplements, mechanical activity prevents myotube atrophy but does not lead to cell growth. Mechanically induced growth is accompanied by significant increases in protein synthesis rates. The increases in protein synthesis and accumulation induced by mechanical stimulation are not inhibited by tetrodotoxin but are significantly reduced in basal medium without supplements. Mechanically stimulated cell growth is thus dependent on medium growth factors but independent of electrical activity.

Verapamil-induced changes of muscle culture acetylcholinesterase

1979 ◽  
Vol 57 (12) ◽  
pp. 1421-1426 ◽  
Author(s):  
Gary T. Patterson ◽  
C. Michael Cisson ◽  
Richard K. Entrikin ◽  
Barry W. Wilson
Keyword(s):  
Ache Activity ◽  
Creatine Phosphokinase ◽  
Pectoral Muscle ◽  
Total Cell ◽  
Cell Protein ◽  
Leucine Incorporation ◽  
Chick Embryos ◽  
Total Cell Protein ◽  
Induced Changes ◽  
Increased Activity

Pectoral muscle of 11-day-old normal chick embryos was cultured for 7 days and then treated with verapamil for up to 48 h to test the hypothesis that verapamil affects acetylcholinesterase (ACHE) activity. Cellular ACHE activity increased, activity released into the medium decreased, and net activity decreased with increasing concentrations of verapamil up to 30 μg/mL. Neither protein synthesis nor total cell protein content changed with concentrations of 1–30 μg of verapamil/mL. One hundred micrograms of verapamil per millilitre was toxic to cultures. To determine the effect of verapamil on newly synthesized ACHE, 30 μg of it per millilitre was added to cells treated with diisopropylphosphorofluoridate (DFP). During recovery from DFP, the amount of newly synthesized ACHE released into the medium was increased threefold. Cellular leucine incorporation, total cell protein, and creatine phosphokinase activity were unaffected by the presence of verapamil during cellular recovery from DFP. The results indicate that verapamil has a direct effect on skeletal muscle cells by specifically decreasing net synthesis of ACHE and (or) inhibiting its release from the cell.

Transcriptional regulation of Na/K-ATPase by corticosteroids, glycyrrhetinic acid and second messenger pathways in rat kidney epithelial cells

1995 ◽  
Vol 15 (1) ◽  
pp. 93-103 ◽  
Author(s):  
C B Whorwood ◽  
P M Stewart
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Rat Kidney ◽  
Total Cell ◽  
Cell Protein ◽  
Mrna Levels ◽  
Subunit Gene ◽  
Total Cell Protein ◽  
Subunit Mrna ◽  
Kinase C

ABSTRACT Corticosteroid regulation of Na/K-ATPase is of key importance in the modulation of Na+ transport across renal tubular epithelia. In amphibian renal cells, aldosterone induction of Na/K-ATPase α1 and β1 subunit gene transcription is mediated by an indirect mechanism dependent on the synthesis of a labile protein. In mammalian target cells, while both mineralo- and glucocorticoids increase the levels of Na/K-ATPase α1 and β1 subunit mRNA and enzyme activity, they are diminished by glycyrrhetinic acid (GE), the active ingredient of licorice. To investigate the mechanisms underlying the regulation of mammalian renal Na/K-ATPase, levels of α1 and β1 mRNA were measured in rat kidney epithelial (NRK-52E) cells treated with a range of concentrations of aldosterone, corticosterone and GE in the presence of a specific inhibitor of mRNA synthesis, dichlororibofuranosylbenzimidazole (DRB), an inhibitor of total RNA synthesis, actinomycin D (ActD), and the protein synthesis inhibitor cycloheximide (CHX). In addition, GE was co-incubated with the sodium channel antagonist benzamiloride (BZ). The increase in both α1 and β1 mRNA levels following aldosterone and corticosterone was completely abolished by treatment with ActD and DRB, while CHX did not affect this response. Similarly, the GE-induced decrease in α1 and β1 mRNA was also completely abolished by ActD and DRB, but not by CHX or by BZ. The half-lives of α1 and β1 mRNA in these cells (means±s.e.m., n=4), estimated from the rate of mRNA decay in the presence of DRB, were 6·8±0·3 and 4·8±0·2 h respectively. This was unaffected by GE. The inhibitory action of GE on α1 and β1 mRNA levels was accompanied by a dose-dependent decrease in levels of intracellular cAMP (means ± s.e.m., n=4) from 395±28 fmol cAMP/μg total cell protein to between 275 ± 19 fmol/μg total cell protein (0·1 μm GE) and 78±11 fmol/μg total cell protein (10 μm GE). This was abolished following down-regulation of protein kinase C by prolonged treatment with the phorbol ester tetradecanoylphorbol-13-acetate (TPA), and by pertussis toxin (PT), but not by cholera toxin (CT). Indeed, subunit mRNA levels were increased by 8-bromo-cAMP (2·2-fold) and stimulators of adenylate cyclase activity, i.e. forskolin (2·1-fold), PT (2·1-fold) and CT (1·9-fold), but not by TPA. In keeping with their effects on GE inhibition of cAMP synthesis, TPA and PT (but not CT) abolished the GE-induced decrease in subunit mRNA. In conclusion, corticosteroid induction and GE inhibition of Na/K-ATPase subunit gene expression in rat kidney epithelial cells occur at the transcriptional level and do not require de novo synthesis of an intermediary protein. Furthermore, GE attenuation of subunit gene transcription may be mediated by both cAMP-dependent protein kinase A and diacylglycerol—protein kinase C pathways via interaction with a PT-sensitive Gi protein.

scholarly journals Cytochalasin D induces increased actin synthesis in HEp-2 cells.

1983 ◽  
Vol 3 (1) ◽  
pp. 132-142 ◽  
Author(s):  
J Tannenbaum ◽  
G C Godman
Keyword(s):  
Concentration Dependence ◽  
Relative Rate ◽  
Relative Increase ◽  
Cytochalasin D ◽  
Total Cell ◽  
Time Dependent ◽  
Cell Protein ◽  
Cytoskeletal Reorganization ◽  
Total Cell Protein ◽  
Cytoskeletal Rearrangement

In HEp-2 cells treated with 0.2 to 2.0 microM cytochalasin D (CD) for 7.5 to 24 h there was a 20 to 50% relative increase in actin content (units of actin per microgram of total cell protein). This augmentation, which was concentration and time dependent, was prevented by treatment with cycloheximide during exposure to CD. A 15 to 20% increase in the relative rate of actin synthesis in CD-treated HEp-2 cells (0.2 to 2.0 microM CD) was detectable after 1 h of treatment and increased to 30 to 50% by 24 h. This increased rate of actin synthesis was apparently responsible for the higher actin content of CD-treated HEp-2 cells. The concentration dependence of these effects of CD on actin metabolism correlated with the pattern seen for CD-triggered changes in cellular morphology and the underlying rearrangements of the actin-containing cytoskeletal structures, suggesting that the effects on metabolism and morphology were interrelated. Since the rapidly occurring cytoskeletal reorganization preceded the effects of CD on actin metabolism, it is proposed that actin synthesis is induced by the cytoskeletal rearrangement resulting from exposure to CD.

Sign in / Sign up

Export Citation Format

Share Document