IN VITRO STUDIES ON COLLAGEN METABOLISM IN METAPHYSEAL RAT BONE

1975 ◽  
Vol 80 (4) ◽  
pp. 784-794 ◽  
Author(s):  
Norvald Langeland ◽  
Vigdis Teig
Keyword(s):  
Incorporation Rate ◽  
In Vitro Studies ◽  
Collagen Metabolism ◽  
Female Rats ◽  
Bone Collagen ◽  
Metaphyseal Bone ◽  
Rat Bone

ABSTRACT In vitro collagen metabolism in metaphyseal bone has been studied during the first few hours and days after the start of in vivo treatment of castrated female rats with various doses of oestradiol-17β. Already during the first 2 h after the start of treatment with oestradiol-17β 2 μg/day and within the first 24 h in the rats receiving 20 μg/day, a reduction of the collagen incorporation rate was demonstrated. The incorporation rates remained at approximately the same reduced level during the following 3 weeks. In rats receiving oestradiol-17β 1 μg/day no such reduced incorporation rate could be demonstrated during the first 36 h after the start of treatment. The bone collagen resorption rate was significantly elevated during the first 3 days of treatment in the animals receiving oestradiol-17β both 1 and 20 μg/day. After this time the resorption rates gradually fell to levels significantly below controls at 3 weeks after start of treatment.

IN VITRO STUDIES ON COLLAGEN METABOLISM IN METAPHYSEAL RAT BONE

1975 ◽  
Vol 80 (4) ◽  
pp. 775-783 ◽  
Author(s):  
Norvald Langeland
Keyword(s):  
Amino Acid ◽  
Collagen Synthesis ◽  
Treated Group ◽  
In Vitro Studies ◽  
Collagen Metabolism ◽  
Bone Collagen ◽  
Accretion Rates ◽  
Different Doses ◽  
Rat Bone

ABSTRACT The effect of oestradiol-17β treatment on bone collagen metabolism in vitro was studied in metaphyseal rat bone. Rats were oophorectomized and subsequently treated for 3 weeks with different doses of oestradiol-17β. Bone pieces were incubated in a modified Krebs-Ringer bicarbonate medium for 6 h. Synthesis of [14C] hydroxyproline from [14C]proline and the incorporation of this amino acid into the bone samples was determined and the collagen synthesis and accretion rates calculated from these data. Collagen resorption rates were calculated from measured release of non-radioactive hydroxyproline to the medium. Castration resulted in an increased rate of accretion and resorption of collagen. All doses of oestradiol tested in this study (1 to 20 μg per animal per day for 3 weeks) decreased both accretion and resorption rates to levels insignificantly different from those of the non-castrated control rats. Only the 2 μg treated group had significantly better collagen balance than the castrated untreated rats.

IN VITRO STUDIES ON COLLAGEN METABOLISM IN METAPHYSEAL RAT BONE

1975 ◽  
Vol 80 (4) ◽  
pp. 795-800 ◽  
Author(s):  
Norvald Langeland ◽  
Vigdis Teig
Keyword(s):  
Collagen Synthesis ◽  
Mature Female ◽  
Parathyroid Glands ◽  
Collagen Metabolism ◽  
Female Rats ◽  
Bone Collagen ◽  
Detectable Effect ◽  
Bone Collagen Synthesis ◽  
Rat Bone

ABSTRACT Oestradiol-17β has been administered to hypophysectomized/castrated and to thyro-parathyroidectomized/castrated young mature female rats. Treatment with oestradiol-17β 5 μg/day per animal, was continued for 3 weeks. Bone pieces from tibia/femur metaphyses were incubated in vitro for 3 h in order to establish the bone collagen synthesis and resorption rates. The results were compared to results from a previous study on castrated female rats with intact hypophysis, thyroid and parathyroid glands. Bone from the thyro-parathyroidectomized/castrated rats treated with oestradiol-17β had a significantly reduced collagen resorption rate in vitro as compared to their paired controls. This is a result consistent with that of castrated female rats with intact thyroid and parathyroid glands treated with oestradiol. Oestradiol-17β had no detectable effect upon collagen metabolism in the hypophysectomized/castrated rats. It is concluded that the effect of oestradiol on bone resorption is not exerted via the parathyroid glands or parathyroid hormone. The possibility that oestrogens may act on bone via the hypophysis is discussed.

Effects of Ghrelin upon Gonadotropin-Releasing Hormone and Gonadotropin Secretion in Adult Female Rats: In vivo and in vitro Studies

2005 ◽  
Vol 82 (5-6) ◽  
pp. 245-255 ◽  
Author(s):  
Rafael Fernández-Fernández ◽  
Manuel Tena-Sempere ◽  
Víctor M. Navarro ◽  
María L. Barreiro ◽  
Juan M. Castellano ◽  
...  
Keyword(s):  
Adult Female ◽  
Gonadotropin Releasing Hormone ◽  
In Vitro Studies ◽  
Female Rats ◽  
Gonadotropin Secretion ◽  
Releasing Hormone

Characterization of the Reproductive Effects of theVgf-Derived Peptide TLQP-21 in Female Rats: In vivo and in vitro Studies

2013 ◽  
Vol 98 (1) ◽  
pp. 38-50 ◽  
Author(s):  
Enrique Aguilar ◽  
Rafael Pineda ◽  
Francisco Gaytán ◽  
Miguel A. Sánchez-Garrido ◽  
Magdalena Romero ◽  
...  
Keyword(s):  
In Vitro Studies ◽  
Female Rats ◽  
Reproductive Effects

Biological and biomedical applications of collagenous biomaterials

1990 ◽  
Vol 48 (3) ◽  
pp. 856-857
Author(s):  
Yasushi P. Kato ◽  
Michael G. Dunn ◽  
Frederick H. Silver ◽  
Arthur J. Wasserman
Keyword(s):  
Biomedical Applications ◽  
Soft Tissues ◽  
Collagen Fibers ◽  
Bone Collagen ◽  
Cover Slip ◽  
Fibroblast Migration ◽  
Cellular Expression ◽  
Defect Repair

Collagenous biomaterials have been used for growing cells in vitro as well as for augmentation and replacement of hard and soft tissues. The substratum used for culturing cells is implicated in the modulation of phenotypic cellular expression, cellular orientation and adhesion. Collagen may have a strong influence on these cellular parameters when used as a substrate in vitro. Clinically, collagen has many applications to wound healing including, skin and bone substitution, tendon, ligament, and nerve replacement. In this report we demonstrate two uses of collagen. First as a fiber to support fibroblast growth in vitro, and second as a demineralized bone/collagen sponge for radial bone defect repair in vivo.For the in vitro study, collagen fibers were prepared as described previously. Primary rat tendon fibroblasts (1° RTF) were isolated and cultured for 5 days on 1 X 15 mm sterile cover slips. Six to seven collagen fibers, were glued parallel to each other onto a circular cover slip (D=18mm) and the 1 X 15mm cover slip populated with 1° RTF was placed at the center perpendicular to the collagen fibers. Fibroblast migration from the 1 x 15mm cover slip onto and along the collagen fibers was measured daily using a phase contrast microscope (Olympus CK-2) with a calibrated eyepiece. Migratory rates for fibroblasts were determined from 36 fibers over 4 days.

The Venom of the Boomslang (Dispholidus Typus): In Vivo and in Vitro Studies

1969 ◽  
Vol 21 (02) ◽  
pp. 234-244 ◽  
Author(s):  
N Mackay ◽  
J.C Ferguson ◽  
Antonia Bagshawe ◽  
A.T.T Forrester ◽  
G.P Mcnicol
Keyword(s):  
In Vitro Studies

SummaryAn account is given of the effects of boomslang venom in man. Evidence was found of a fibrinolytic state apparently secondary to the coagulant action of the venom. These features rapidly responded to the administration of specific antivenom. In vitro studies, using a homogenate of boomslang parotids, confirmed the coagulant properties of the venom and showed them to be of much greater potency than the proteolytic actions.

Effect of X-irradiation on gene expression of rat liver chemokines: in vivo and in vitro studies

2008 ◽  
Vol 46 (01) ◽  
Author(s):  
F Moriconi ◽  
H Christiansen ◽  
H Christiansen ◽  
N Sheikh ◽  
J Dudas ◽  
...  
Keyword(s):  
Gene Expression ◽  
Rat Liver ◽  
In Vitro Studies ◽  
X Irradiation
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