COLLAGEN BIOSYNTHESIS

Quantitative studies of collagen formation by chick embryonic lung tissue grown in media deficient in, or completely lacking, ascorbic acid have been carried out. Cell growth and collagen formation in such cultures can proceed almost normally in media lacking ascorbic acid. Ascorbic acid in combination with whole embryo extract, dialyzed media, or synthetic mixture number 703 was found to have no appreciable effect on cell growth or total collagen formation. This is in marked contrast to the almost total failure of collagen formation in scorbutic animals and suggests that for slow collagen biosynthesis as distinct from more prolific collagen-producing systems, ascorbic acid plays an indirect role.

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Action of allogeneic serum from a pregnant pneumonectomized rat on embryonic lung tissue

Bulletin of Experimental Biology and Medicine ◽

10.1007/bf00801315 ◽

1978 ◽

Vol 86 (1) ◽

pp. 931-935

Author(s):

I. I. Orlova ◽

N. G. Lisatova ◽

S. D. Mikhal'chenko

Keyword(s):

Lung Tissue ◽

Embryonic Lung

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The structure of long-surviving homografts of embryonic lung tissue in rats

Transplantation Journal ◽

10.1097/00007890-196407000-00060 ◽

1964 ◽

Vol 2 (4) ◽

pp. 576

Author(s):

R. A. Willis ◽

L. T. Hou

Keyword(s):

Lung Tissue ◽

Embryonic Lung

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Stabilization of papain from papaya peels / Estabilización de la papaína de la cáscara de papaya

Food Science and Technology International ◽

10.1177/108201329800400304 ◽

1998 ◽

Vol 4 (3) ◽

pp. 179-187 ◽

Cited By ~ 6

Author(s):

N. Espin ◽

M.N. Islam

Keyword(s):

Ascorbic Acid ◽

Enzyme Activity ◽

Protective Effect ◽

Total Concentration ◽

Sodium Ascorbate ◽

Sodium Metabisulfite ◽

Appreciable Effect ◽

Original Activity ◽

Before And After ◽

Erythorbic Acid

Crude papain in papaya peels was stabilized before drying by the addition of various chemicals (ascorbic acid, sodium ascorbate, erythorbic acid, sodium erythorbate, sodium metabisulfite, sodium tetrathionate, 4-hexylresorcinol, t-butyl hydroquinone [TBHQ], rutin, α-tocopherol, trehalose, and sucrose). Chemicals were added to the ground papaya peels at 0, 0.12, 0.25, 0.5, 0.75, 1, 1.25, and 1.5% (w /w). Drying temperatures were 40, 55 and 60 °C. Enzyme activity was measured before and after drying by the casein digestion method. Percentage of enzyme activity retained (% EAR) was calculated by assigning a value of 100% EAR to fresh peels. Possible synergism between chemicals was also studied for a 1:1 ratio chemical/chemical at 1% total concentration. The highest % EAR was obtained at 55 °C for all chemicals except for sucrose and trehalose which showed their best effect at 40 °C. TBHQ rutin, α-tocopherol and 4-hexylresorcinol showed a destabilizing effect. Maximum protective effect occurred at 1% concentration. At this concentration sodium tetrathionate showed the best protective effect (90% EAR) followed by sodium metabisulfite (85% EAR), while both sodium ascorbate and sodium erythorbate retained 75% of the original activity. Ascorbic acid and erythorbic acid were 10% less effective than their corresponding sodium salts, possibly due to lower pH. Trehalose showed only 57 % EAR while sucrose failed to produce any appreciable effect. No synergistic effect was shown by any combination of chemicals.

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Ascorbic acid and transforming growth factor-β1 increase collagen biosynthesis via different mechanisms: Coordinate regulation of proα1(I) and proα1(III) collagens

Archives of Biochemistry and Biophysics ◽

10.1016/0003-9861(92)90533-3 ◽

1992 ◽

Vol 295 (2) ◽

pp. 397-403 ◽

Cited By ~ 56

Author(s):

Charlotte L. Phillips ◽

Shingo Tajima ◽

Sheldon R. Pinnell

Keyword(s):

Ascorbic Acid ◽

Growth Factor ◽

Transforming Growth Factor ◽

Transforming Growth Factor Β1 ◽

Collagen Biosynthesis ◽

Coordinate Regulation

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WOUND HEALING AND COLLAGEN FORMATION

The Journal of Cell Biology ◽

10.1083/jcb.22.2.365 ◽

1964 ◽

Vol 22 (2) ◽

pp. 365-398 ◽

Cited By ~ 78

Author(s):

Russell Ross ◽

Earl P. Benditt

Keyword(s):

Endoplasmic Reticulum ◽

Ascorbic Acid ◽

Messenger Rna ◽

Complete Disappearance ◽

Extracellular Material ◽

Material Characteristic ◽

Collagen Formation ◽

Hydroxyamino Acids ◽

Curved Paths ◽

Filamentous Material

The changes in scorbutic wounds following the administration of ascorbic acid have been investigated using the techniques of electron microscopy, histochemistry, and autoradioggraphy. Particular attention has been paid to the changes seen in the endoplasmic reticulum of the fibroblasts and to the identity of the extracellular filamentous material characteristic of scorbutic wounds. Seven-day-old wounds in scorbutic guinea pigs were examined prior to and from one to 72 hours following the administration of vitamin C. Fibroblasts from wounds of normal animals demonstrate a characteristic configuration of the ribosomes of the endoplasmic reticulum which is suggested to be analogous to polyribosomes described in cells synthesizing protein such as the reticulocyte. Tangential views of the membranes of the ergastoplasm show the ribosomes to be grouped in paired rows which take both straight and curved paths. This configuration is lost in scurvy and can be seen to begin to reappear as early as 4 hours after giving ascorbic acid. With increasing time, the morphology of the ribosomal aggregates approximates that seen in normal cells, so that by 24 hours their reorientation is complete. It is suggested that one of the disturbances in scurvy may relate to an alteration either in messenger RNA, in the ability of the ribosomes to relate to the messenger, or in the membranes of the ergastoplasm. In addition, the lack of formation of hydroxyamino acids necessary for completing collagen synthesis may be related to the architecture of the ribosomal aggregates. Extracellular collagen fibrils appear concomitant with the restoration of ribosomal and ergastoplasmic morphology as early as 12 hours after administration of ascorbic acid, with complete disappearance of the scorbutic extracellular material within 24 hours. Observations of this scorbutic material do not support the concept that it is a collagen precursor.

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