Stimulation of cardiac protein synthesis by insulin-like growth factors

1991 ◽  
Vol 19 (3) ◽  
pp. 277S-277S
Author(s):  
STEPHEN J. FULLER ◽  
JOHN R. MYNETT ◽  
PETER H. SUGDEN
Keyword(s):  
Protein Synthesis ◽  
Growth Factors ◽  
Stimulation Of ◽  
Insulin Like Growth Factors

scholarly journals Stimulation of cardiac protein synthesis by insulin-like growth factors

1992 ◽  
Vol 282 (1) ◽  
pp. 85-90 ◽  
Author(s):  
S J Fuller ◽  
J R Mynett ◽  
P H Sugden
Keyword(s):  
Protein Synthesis ◽  
Growth Factors ◽  
Growth Factor ◽  
Lactate Production ◽  
Adult Rats ◽  
Mechanistic Basis ◽  
High Concentrations ◽  
Stimulation Of ◽  
Insulin Like Growth Factors

The effects of the insulin-like growth factors (IGF)-1 and -2 on the rates of protein synthesis in freshly isolated cardiac myocytes from adult rats were compared with those of insulin. At concentrations of 50-100 nM, each agent stimulated protein synthesis by about 70%. There was no additional stimulation upon combination of insulin with IGF-1 or IGF-2 at these high concentrations. When compared over a range of concentrations, the relative response to each agent was insulin greater than IGF-1 greater than or equal to IGF-2. Concentrations of 1 nM-IGF-1, 1 nM-IGF-2 or 0.2 nM-insulin enhanced the rates of protein synthesis by 36%, 30% or 34% respectively. A combination of 0.2 nM-insulin and 1 nM-IGF-1 or 1 nM-IGF-2 increased the stimulation of protein synthesis to 46%. In contrast, the effects of 1 nM-IGF-1 and 1 nM-IGF-2 were not additive. The possible mechanistic basis for this difference is discussed. At a concentration of 50 nM, epidermal growth factor (EGF), fibroblast growth factor and platelet-derived growth factor were each without effect on protein synthesis. In anterogradely perfused rat heart preparations, 2 nM-IGF-1 or 2.4 nM-IGF-2 increased protein synthesis and lactate production, but 9.2 nM-EGF did not. From a consideration of the plasma free concentrations of IGF-1 and IGF-2, we suggest that these factors may contribute to the maintenance of rate of cardiac protein synthesis in vivo.

scholarly journals Insulin-like growth factors 1 and 2 in bovine colostrum. Sequences and biological activities compared with those of a potent truncated form

1988 ◽  
Vol 251 (1) ◽  
pp. 95-103 ◽  
Author(s):  
G L Francis ◽  
F M Upton ◽  
F J Ballard ◽  
K A McNeil ◽  
J C Wallace
Keyword(s):  
Growth Factors ◽  
Biological Activities ◽  
Structure And Function ◽  
Bovine Colostrum ◽  
Amino Acid Sequences ◽  
Truncated Form ◽  
Reverse Phase ◽  
And Function ◽  
Stimulation Of ◽  
Insulin Like Growth Factors

1. Insulin-like growth factors 1 and 2 (IGF-1 and IGF-2) together with a truncated form of IGF-1 were purified to homogeneity from bovine colostrum. 2. Two forms of IGF-1 were totally resolved from IGF-2 in the purification by h.p.l.c. involving cation-exchange and reverse-phase columns. 3. The complete amino acid sequences for all three forms of IGF were determined. The sequence of bovine IGF-1 was found to be identical with that of human IGF-1, and that of the variant lacked the N-terminal tripeptide Gly-Pro-Glu (-3N:IGF-1). Bovine IGF-2 was found to differ in three residues of the C-domain compared with human IGF-2, with serine, isoleucine and asparagine substituted for alanine, valine and serine respectively at positions 32, 35 and 36. 4. Protein synthesis in L6 rat myoblasts was stimulated and protein degradation inhibited in a co-ordinate response with all three IGFs. The relative potency in both processes was −3N:IGF-1 greater than IGF-1 greater than IGF-2. A similar order of potency was obtained for the stimulation of DNA synthesis by −3N:IGF-1 and IGF-1. The approximately 10-fold effect on biological activity of removing the N-terminal tripeptide is unexpected in view of current information on IGF-1 structure and function.

Effect of purified somatomedins on thymidine incorporation into lectin-activated human lymphocytes

1983 ◽  
Vol 102 (1) ◽  
pp. 21-26 ◽  
Author(s):  
Rose-Marie Schimpff ◽  
Anne-Marie Repellin ◽  
Alessandro Salvatoni ◽  
Geneviève Thieriot-Prevost ◽  
Pierre Chatelain
Keyword(s):  
Growth Factors ◽  
Thymidine Incorporation ◽  
Human Lymphocytes ◽  
Human Cells ◽  
Serum Factors ◽  
Somatomedin C ◽  
Activated Lymphocytes ◽  
Different Doses ◽  
Stimulation Of ◽  
Insulin Like Growth Factors

Abstract. These data describe the effects of purified preparations of several growth factors on thymidine incorporation into phyto-haemagglutinin-activated (PHA) human lymphocytes. The somatomedins selected for this study included human somatomedins A and C, insulin-like growth factors (IFG1) and IGF2) and multiplication stimulating activity (MSA). Assays were carried out with and without serum. Complementary assays were performed with a low-molecular serum ultrafiltrate added to somatomedin C and to MSA. We found that all the peptides tested, except MSA, stimulated thymidine incorporation into PHA-activated lymphocytes in a dosedependent manner, even though different doses were required to obtain a response. The data reported point out the multiplicity and the interrelationships of the serum factors involved in the stimulation of human cells growth.

Transcriptional activation of mammalian ornithine decarboxylase during stimulated growth

1987 ◽  
Vol 7 (7) ◽  
pp. 2641-2643
Author(s):  
A Katz ◽  
C Kahana
Keyword(s):  
Protein Synthesis ◽  
Growth Factors ◽  
Ornithine Decarboxylase ◽  
Transcriptional Activation ◽  
Tumor Promoter ◽  
Transcriptional Analysis ◽  
Mouse Fibroblasts ◽  
Serum Stimulation ◽  
Stimulation Of

Cloned ornithine decarboxylase (ODC) (EC 4.1.1.17) cDNA was used to investigate the mechanisms which mediate the mitogenic induction of mammalian ODC. Stimulation of quiescent BALB/c 3T3 mouse fibroblasts with purified fibroblast and platelet-derived growth factors and with the tumor promoter 12-O-tetradecanoylphorbol-13-acetate results in a rapid and dramatic increase in ODC mRNA, similar to the increase caused by serum stimulation. Using nuclear runoff transcriptional analysis, we demonstrate that an increase in ODC transcription accounts for the mitogenic induction of ODC mRNA, and using cycloheximide together with the stimulating mitogen, we found that the mitogenic induction of ODC is dependent on ongoing protein synthesis in the stimulated cells.

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