STIMULATION OF CARTILAGE ZONES OF THE CALF COSTOCHONDRAL GROWTH PLATE IN VITRO BY GROWTH HORMONE DEPENDENT RAT PLASMA SOMATOMEDIN ACTIVITY

1979 ◽  
Vol 83 (2) ◽  
pp. 219-227 ◽  
Author(s):  
D. J. HILL
Keyword(s):  
Growth Hormone ◽  
Growth Plate ◽  
Rat Plasma ◽  
Cell Replication ◽  
Matrix Synthesis ◽  
Growth Plate Cartilage ◽  
Cartilage Cells ◽  
Activity Dependent ◽  
Stimulation Of

The actions of rat plasma somatomedin activity dependent on growth hormone were investigated in vitro on separated zones of cartilage from the calf costochondral junction. Plasma somatomedin maximally stimulated the uptake of [3H]thymidine into cartilage cells of the proliferating region. Cartilage deeper in the growth plate possessed the highest uptake of [35S]sulphate which was also stimulated by somatomedin. Somatomedin, therefore, appears to promote both cell replication and matrix synthesis throughout the growth plate cartilage although the two processes were greatest in different cartilage regions. Growth hormone or tri-iodothyronine did not directly alter the uptake of either isotope into the growth plate cartilage.

scholarly journals 278 EXPRESSION AND FUNCTION OF THE ARYL HYDROCARBON RECEPTOR IN GROWTH PLATE CARTILAGE CELLS IN VITRO

2010 ◽  
Vol 18 ◽  
pp. S124-S125
Author(s):  
M. Widerak ◽  
M. Presume ◽  
K. Tahiri ◽  
M.-F. Dumontier ◽  
M.-T. Corvol ◽  
...  
Keyword(s):  
Aryl Hydrocarbon Receptor ◽  
Growth Plate ◽  
Growth Plate Cartilage ◽  
Aryl Hydrocarbon ◽  
Cartilage Cells ◽  
And Function

THE INFLUENCE OF PITUITARY GROWTH HORMONE ON PLASMA INSULIN ACTIVITY

1956 ◽  
Vol 13 (3) ◽  
pp. 335-348 ◽  
Author(s):  
P. J. RANDLE ◽  
F. G. YOUNG
Keyword(s):  
Growth Hormone ◽  
Blood Plasma ◽  
Rat Plasma ◽  
Freezing And Thawing ◽  
Pituitary Growth Hormone ◽  
Short Period ◽  
Insulin Activity ◽  
Constant Dose ◽  
Stimulation Of

SUMMARY The insulin activity of blood plasma has been studied by the application of a method of assay based upon the stimulation of the in vitro uptake of glucose by the isolated rat diaphragm. Treatment of the intact rat with growth hormone did not significantly alter the insulin activity of the blood plasma. Hypophysectomy of the rat greatly reduced the insulin activity of the plasma, though this fall could be prevented by treatment with growth hormone begun immediately after hypophysectomy. Treatment with growth hormone of the intact cat, but not of the depancreatized cat receiving a constant dose of insulin, greatly increased the insulin activity of the plasma. The in vitro addition of growth hormone to human or rat plasma did not alter its insulin activity. The plasma from cats rendered permanently diabetic by a short period of treatment with growth hormone possessed no significant insulin activity. After the plasma had been repeatedly frozen and thawed, insulin activity was found to be present. No appearance of insulin activity on freezing and thawing was observed with plasma from normal or depancreatized cats. The significance of the influence of growth hormone upon the secretion of insulin by the pancreas is discussed.

scholarly journals Establishment of a New Device for Electrical Stimulation of Non-Degenerative Cartilage Cells In Vitro

2021 ◽  
Vol 22 (1) ◽  
pp. 394
Author(s):  
Simone Krueger ◽  
Alexander Riess ◽  
Anika Jonitz-Heincke ◽  
Alina Weizel ◽  
Anika Seyfarth ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Electric Fields ◽  
Cartilage Tissue ◽  
Type I ◽  
Dependent Manner ◽  
New Device ◽  
Alternating Electric Fields ◽  
Cartilage Cells ◽  
Stimulation Of

In cell-based therapies for cartilage lesions, the main problem is still the formation of fibrous cartilage, caused by underlying de-differentiation processes ex vivo. Biophysical stimulation is a promising approach to optimize cell-based procedures and to adapt them more closely to physiological conditions. The occurrence of mechano-electrical transduction phenomena within cartilage tissue is physiological and based on streaming and diffusion potentials. The application of exogenous electric fields can be used to mimic endogenous fields and, thus, support the differentiation of chondrocytes in vitro. For this purpose, we have developed a new device for electrical stimulation of chondrocytes, which operates on the basis of capacitive coupling of alternating electric fields. The reusable and sterilizable stimulation device allows the simultaneous use of 12 cavities with independently applicable fields using only one main supply. The first parameter settings for the stimulation of human non-degenerative chondrocytes, seeded on collagen type I elastin-based scaffolds, were derived from numerical electric field simulations. Our first results suggest that applied alternating electric fields induce chondrogenic re-differentiation at the gene and especially at the protein level of human de-differentiated chondrocytes in a frequency-dependent manner. In future studies, further parameter optimizations will be performed to improve the differentiation capacity of human cartilage cells.

scholarly journals Influence of intermittent compressive force on proteoglycan content in calcifying growth plate cartilage in vitro.

1987 ◽  
Vol 262 (32) ◽  
pp. 15490-15495
Author(s):  
J Klein-Nulend ◽  
J P Veldhuijzen ◽  
R J van de Stadt ◽  
G P van Kampen ◽  
R Kuijer ◽  
...  
Keyword(s):  
Growth Plate ◽  
Compressive Force ◽  
Growth Plate Cartilage ◽  
Proteoglycan Content

scholarly journals Biosynthesis of growth hormone in the rat anterior pituitary gland. Stimulation of biosynthesis in vitro by insulin

1973 ◽  
Vol 134 (4) ◽  
pp. 1103-1113 ◽  
Author(s):  
A. Betteridge ◽  
M. Wallis
Keyword(s):  
Growth Hormone ◽  
Anterior Pituitary ◽  
Rna Synthesis ◽  
Glucose Utilization ◽  
Actinomycin D ◽  
Hormone Synthesis ◽  
Pituitary Glands ◽  
Hormone Biosynthesis ◽  
Stimulation Of

The effect of insulin on the incorporation of radioactive leucine into growth hormone was investigated by using rat anterior pituitary glands incubated in vitro. A 50% stimulation over control values was observed at insulin concentrations above 2μm (280munits/ml). The effect was specific for growth hormone biosynthesis, over the range 1–5μm-insulin (140–700munits/ml). Lower more physiological concentrations had no significant effect in this system. Above 10μm (1.4 units/ml) total protein synthesis was also increased. The stimulation of growth hormone synthesis could be partially blocked by the addition of actinomycin D, suggesting that RNA synthesis was involved. Insulin was found to stimulate the rate of glucose utilization in a similar way to growth hormone synthesis. 2-Deoxyglucose and phloridzin, which both prevented insulin from stimulating glucose utilization, also prevented the effect of insulin on growth hormone synthesis. If glucose was replaced by fructose in the medium, the effect of insulin on growth hormone synthesis was decreased. We conclude that the rate of utilization of glucose may be an important step in mediating the effect of insulin on growth hormone synthesis.

Ligand-dependent, Pit-1/growth hormone factor-1 (GHF-1)-independent transcriptional stimulation of rat growth hormone gene expression by thyroid hormone receptors in vitro

1993 ◽  
Vol 13 (3) ◽  
pp. 1719-1727
Author(s):  
C S Suen ◽  
W W Chin
Keyword(s):  
Gene Expression ◽  
Growth Hormone ◽  
Thyroid Hormone ◽  
Promoter Activity ◽  
Hormone Receptors ◽  
Nuclear Extract ◽  
In Vitro Transcription ◽  
Stimulation Of ◽  
Transcriptional Stimulation

The expression of the rat growth hormone (rGH) gene in the anterior pituitary gland is modulated by Pit-1/GHF-1, a pituitary-specific transcription factor, and by other more widely distributed factors, such as the thyroid hormone receptors (TRs), Sp1, and the glucocorticoid receptor. Thyroid hormone (T3)-mediated transcriptional stimulation of rGH gene expression has been extensively studied in vivo and in vitro including the measurements of (i) rGH mRNA by blot hybridization, (ii) transcriptional rate of rGH gene by nuclear run-on, and (iii) reporter gene expression in which a chimeric plasmid containing 5'-flanking sequences of the rGH gene linked to a reporter gene has been transfected either stably or transiently into pituitary and/or nonpituitary cells. From these studies, it has been suggested that the Pit-1/GHF-1 binding site is necessary for full T3 action. We developed a cell-free in vitro transcription system to examine further the roles of the TRs and Pit-1/GHF-1 in rGH gene activation. Using GH3 nuclear extract as a source of TRs and Pit-1/GHF-1, this in vitro transcription assay showed that T3 stimulation of rGH promoter activity is dependent on the addition of T3 to the GH3 nuclear extract. This transcriptional stimulation was augmented with increasing concentrations of ligand and was T3, but not T4 or reverse T3, specific. T3-mediated stimulation of rGH promoter activity was completely abolished by preincubation of the nuclear extract with rGH-thyroid hormone response element (-200 to -160) but not with Pit-1/GHF-1 (-137 to -65) oligonucleotides. Further, neither deletion of both Pit-1/GHF-1 binding sites nor mutation of the proximal Pit-1/GHF-1 binding site from the rGH promoter abrogated the T3 effect. These results provide evidence that T3-stimulated rGH promoter activity is independent of Pit-1/GHF-1 and raise the possibility that the stimulation of rGH gene expression by T3 might involve direct interaction of TRs with the general transcriptional apparatus.

Triiodothyronine stimulates cartilage growth and maturation by different mechanisms

1987 ◽  
Vol 252 (2) ◽  
pp. E176-E182 ◽  
Author(s):  
W. M. Burch ◽  
J. J. Van Wyk
Keyword(s):  
Alkaline Phosphatase ◽  
Phosphatase Activity ◽  
Growth Plate ◽  
Alkaline Phosphatase Activity ◽  
Growth Response ◽  
Growth Effect ◽  
Cartilage Growth ◽  
Growth Plate Cartilage ◽  
Cartilage Differentiation

The mechanisms by which triiodothyronine (T3) stimulates growth and maturation of growth-plate cartilage in vitro were studied by incubating embryonic chick pelvic cartilages in serum-free medium in the presence and absence of T3 for 3 days. To determine whether T3 might stimulate production of somatomedins by the cartilage, medium from cartilage incubated with and without T3 was assayed for somatomedin C (Sm-C) by radioimmunoassay. No difference in Sm-C content was found. However, cartilage incubated with T3 and increasing amounts of human Sm-C (0.5-20 ng/ml) weighed more and had greater amounts of glycosaminoglycan than cartilage incubated in the same concentrations of Sm-C without T3, suggesting that T3 enhances the growth effect of somatomedin. We added a monoclonal antibody to Sm-C (anti-Sm-C) to the organ culture to determine whether T3's stimulatory effect on cartilage growth could be blocked. The anti-Sm-C inhibited growth of cartilage incubated in medium alone and blocked the growth response to T3. By using alkaline phosphatase as a biochemical marker to follow maturation, we found that T3 stimulated a 57% increase in alkaline phosphatase activity above cartilage incubated in medium alone and that anti-Sm-C did not inhibit T3's stimulatory effect on alkaline phosphatase activity. We propose two different mechanisms by which T3 affects growth-plate cartilage: T3 promotes cartilage growth primarily through enhancing the effect of somatomedin, and T3 stimulates cartilage maturation possibly by accelerating the normal process of cartilage differentiation from proliferative to hypertrophic chondrocytes.

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