scholarly journals Effects of anabolic agents on protein breakdown in L6 myoblasts

1983 ◽  
Vol 210 (1) ◽  
pp. 243-249 ◽  
Author(s):  
F J Ballard ◽  
G L Francis
Keyword(s):  
Growth Factors ◽  
Anabolic Steroids ◽  
Calf Serum ◽  
Foetal Calf Serum ◽  
Protein Breakdown ◽  
Anabolic Agents ◽  
Glucocorticoid Response ◽  
Catabolic Response ◽  
High Concentrations ◽  
Foetal Bovine Serum

1. Protein degradation in rat L6 myoblasts is inhibited by high concentrations of insulin as well as by foetal bovine serum and bovine colostrum, mixtures rich in growth-factor activity. 2. Growth factors achieve maximal effects within 2 h after addition to the cell cultures, but these diminish with time. Indeed, during incubations greater than 12 h, foetal calf serum actually stimulates protein breakdown. The changed response, however, is not due to the depletion of growth factors from serum. 3. Protein breakdown is stimulated by dexamethasone by a process that takes several hours to be expressed, but is more pronounced over a 4 h measurement period than over 18h. The glucocorticoid response is prevented by insulin or by cycloheximide. 4. Anabolic agents such as trenbolone, diethylstilboestrol and testosterone do not alter rates of intracellular protein breakdown and do not interfere with the glucocorticoid-induced catabolic response. 5. The results are consistent with anabolic steroids and related agents acting indirectly on muscle, perhaps via altering concentrations of growth factors of the somatomedin type.

scholarly journals Insulin and growth factors stimulate the phosphorylation of a Mr-22000 protein in 3T3-L1 adipocytes

1983 ◽  
Vol 214 (1) ◽  
pp. 11-19 ◽  
Author(s):  
P J Blackshear ◽  
R A Nemenoff ◽  
J Avruch
Keyword(s):  
Growth Factors ◽  
Growth Factor ◽  
Insulin Treatment ◽  
Calf Serum ◽  
Fold Increase ◽  
Foetal Calf Serum ◽  
Heat Stable ◽  
Maximal Stimulation ◽  
Heat Stable Protein ◽  
Epidermal Growth

Insulin, epidermal growth factor (EGF), platelet-derived growth factor, multiplication-stimulating activity and 10% foetal-calf serum each stimulated the phosphorylation of a cytosolic Mr-22000 acidic heat-stable protein in Swiss mouse 3T3-L1 adipocytes. Phosphorylation of this protein was not stimulated by isoprenaline or dibutyryl cyclic AMP. The effect of insulin was maximal (3-fold increase) by 10 min; half-maximal stimulation was observed at 70 pM-insulin. Both [32P]phosphoserine and [32P]phosphothreonine residues were present in the Mr-22000 protein after insulin- and growth-factor-stimulated phosphorylation, but no [32P]phosphotyrosine. The major site of insulin- and EGF-stimulated phosphorylation appeared to be a threonine residue, in contrast with previously studied insulin-stimulated phosphorylation of serine residues. Insulin treatment appeared to result in a shift of the protein toward the anode on isoelectric focusing. Insulin and EGF present simultaneously did not lead to phosphorylation beyond that seen with each hormone singly. We surmise that insulin, EGF and perhaps other growth factors may activate a common protein kinase or inhibit a common protein phosphatase in 3T3-L1 adipocytes which acts on the Mr-22000 protein.

scholarly journals Regulation of protein accumulation in cultured cells

1982 ◽  
Vol 208 (2) ◽  
pp. 275-287 ◽  
Author(s):  
F J Ballard
Keyword(s):  
Protein Synthesis ◽  
Cell Lines ◽  
Mammalian Cells ◽  
Cultured Cells ◽  
Calf Serum ◽  
Protein Accumulation ◽  
Foetal Calf Serum ◽  
Protein Breakdown ◽  
Breakdown Rates ◽  
Human Breast Carcinoma Cells

1. A technique is described whereby protein synthesis, protein breakdown and net protein accumulation are measured separately in monolayer cultures of mammalian cells. All rates are expressed as microgram of protein per 18 h incubation. 2. Under most incubation conditions with either L6 rat myoblasts or T47D human breast carcinoma cells the rates of protein accumulation, determined directly, agreed with the rates obtained by subtracting protein breakdown from protein synthesis. 3. Foetal calf serum, human and bovine colostrum, human milk and insulin increased protein accumulation in both cell lines, mainly as a consequence of effects on protein synthesis. 4. NH4Cl, in addition to inhibiting protein breakdown in both cell lines in the presence and in the absence of serum, stimulated protein synthesis in L6 myoblasts. 5. Leupeptin slightly inhibited protein breakdown without affecting protein-synthesis rates. 6. Cycloheximide almost completely inhibited protein synthesis, but restricted the net loss of cell proteins under most conditions because protein-breakdown rates were also decreased. 7. The assumptions, limitations and potential application of this technique for evaluating changes in protein turnover are described.

Potassium and calcium currents activated by foetal calf serum in Balb-c 3T3 fibroblasts

1992 ◽  
Vol 1112 (2) ◽  
pp. 241-245 ◽  
Author(s):  
Davide Lovisolo ◽  
Luca Munaron ◽  
Francesco M. Baccino ◽  
Gabriella Bonelli
Keyword(s):  
Calf Serum ◽  
Calcium Currents ◽  
Foetal Calf Serum ◽  
3T3 Fibroblasts

scholarly journals Rotavirus Persistence in Cell Cultures: Selection of Resistant Cells in the Presence of Foetal Calf Serum

1983 ◽  
Vol 64 (5) ◽  
pp. 1101-1110 ◽  
Author(s):  
A. Chiarini ◽  
S. Arista ◽  
A. Giammanco ◽  
A. Sinatra
Keyword(s):  
Cell Cultures ◽  
Calf Serum ◽  
Foetal Calf Serum ◽  
Selection Of ◽  
Resistant Cells

scholarly journals Control by fibroblast growth factor of differentiation in the BC3H1 muscle cell line.

1985 ◽  
Vol 100 (5) ◽  
pp. 1540-1547 ◽  
Author(s):  
B Lathrop ◽  
E Olson ◽  
L Glaser
Keyword(s):  
Growth Factor ◽  
Cell Growth ◽  
Fibroblast Growth Factor ◽  
Cell Line ◽  
Calf Serum ◽  
Specific Protein ◽  
Fibroblast Growth ◽  
Mouse Muscle ◽  
Differentiated Cells ◽  
High Concentrations

The regulation of creatine phosphokinase (CPK) expression by polypeptide growth factors has been examined in the clonal mouse muscle BC3H1 cell line. After arrest of cell growth by exposure to low concentrations of serum, BC3H1 cells accumulate high levels of muscle-specific proteins including CPK. The induction of this enzyme is reversible in the presence of high concentrations of fetal calf serum, which cause quiescent, differentiated cells to reenter the cell cycle. Under these conditions, the rate of CPK synthesis is drastically reduced. We show in the present communication that either pituitary-derived fibroblast growth factor (FGF) or brain-derived FGF are as effective as serum in repressing the synthesis of CPK when added to quiescent, differentiated cells. The decrease in the rate of synthesis of CPK occurs within 22 h after the addition of pituitary FGF to the cells. Pituitary FGF had very little effect, if any, on the rate CPK degradation. The overall rate of protein synthesis and the pattern of synthesis of the major polypeptides made by these cells was not altered by the addition of FGF. Although pituitary FGF was mitogenic for BC3H1 cells, the rate of cell growth was not absolutely correlated with the extent of repression of CPK. Brain-derived FGF fully repressed CPK induction under conditions where it showed no significant mitogenic activity. These results show that the expression of a muscle-specific protein, CPK, can be controlled by a single defined polypeptide growth factor in fully differentiated cultures, and that initiation of cell division is not required for their regulation to take place.

Restriction of foetal calf serum-induced cytotoxicity by human T-cells

1981 ◽  
Vol 3 (2) ◽  
pp. 81-85 ◽  
Author(s):  
I.S. Misko ◽  
R.G. Kane ◽  
J.H. Pope
Keyword(s):  
T Cells ◽  
Calf Serum ◽  
Foetal Calf Serum ◽  
Human T Cells

Drug activity against Onchocerca gutturosa males in vitro: a model for chemotherapeutic research on onchocerciasis

1987 ◽  
Vol 61 (4) ◽  
pp. 271-281 ◽  
Author(s):  
Simon Townson ◽  
C. Connelly ◽  
A. Dobinson ◽  
R. Muller
Keyword(s):  
Culture System ◽  
Serum Proteins ◽  
Good Condition ◽  
Calf Serum ◽  
New Drugs ◽  
Foetal Calf Serum ◽  
Partial Recovery ◽  
Feeder Cells ◽  
Compound Identification

ABSTRACTAn in vitro system for chemotherapeutic research using adult male Onchocerca gutturosa has been developed as a model for O. volvulus. Using a culture system consisting of medium MEM+10% heat inactivated foetal calf serum (IFCS)+LLCMK2 (monkey kidney) feeder cells in an atmosphere of 5% CO2 in air, we examined the effects of a range of antiparasitic drugs on worm motility. Ivermectin, levamisole, furapyrimidone, Mel W, chloroquine, metrifonate, flubendazole, amoscanate and the Ciba-Geigy compounds CGP 6140, CGP 20′376 and CGI 17658 either immobilized or significantly reduced motility levels at a concentration of 5x10−5M or less within a 7-day period. Worms were affected at very low concentrations by ivermectin (effective conc. to reduce motility levels to 50% of controls, 3.14x10−8M), levamisole (7.95x10−8M), CGP 6140 (8.87x10−9M) and CGP 20′376 (2.78x10−8M). Difficulties were experienced in accurately repeating the immotile endpoint for levamisole due to an inconsistent partial recovery of motility. Over a 7-day period diethylcarbamazine had little effect on motility levels, while suramin caused a slight increase in activity compared to controls at some timepoints. Subsequent experiments demonstrated some differences in drug efficacy depending on the presence or absence of serum and feeder cells in the culture system probably because of drug avidly binding to serum proteins. However, serum and cells were found to be essential ingredients of the culture system to maintain worms in good condition, indicating that new drugs should be evaluated both in the presence and absence of serum and cells. Comparisons were made between the responses of O. gutturosa and Brugia pahangi to certain drugs and these species were found to significantly differ in their sensitivities to ivermectin and a novel compound (Wellcome), indicating that Onchocerca parasites should be used wherever possible for compound identification and development intended for the treatment of onchocerciasis. The in vitro system described here, using male O. gutturosa, provides a basis for further research and a practical alternative to O. volvulus.

‘Spontaneous’ sex reversal in organ cultures of the embryonic male gonad of the bird

Development ◽  
1974 ◽  
Vol 31 (3) ◽  
pp. 611-620
Author(s):  
Gregory F. Erickson
Keyword(s):  
Germ Cells ◽  
Primordial Germ Cells ◽  
Calf Serum ◽  
Sex Reversal ◽  
Biologically Active ◽  
Foetal Calf Serum ◽  
Developmental Sequence ◽  
Organ Cultures ◽  
Male Gonad ◽  
Ovarian Cortex

The left embryonic testis of the bird (4–8 days of incubation) was organ cultured in medium that contained 10% foetal calf serum. Under these conditions, the germinal epithelium (GE) of the 4-day gonad differentiates into an ovarian cortex and the male primordial germ cells (PGCs) complete a developmental sequence similar to normal oocytes, i.e. they divide mitotically, develop a Balbiani body, divide synchronously in groups of two, four, and eight germ cells, and some enter pre-leptotene. No medullary tissue develops in the 4-day explants. The pieces of 6- and 8-day gonad differentiate into true ovotestes in which the GE develops into a cortex and the medulla develops into seminiferous cords. The PGCs in the cortex differentiate as oocytes and those in the seminiferous cords differentiate as spermatogonia. The possibility that biologically active oestrogens are present in the growth medium is discussed.

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