An electron optical study of experimental scurvy

Peach, Roy

doi:10.1016/s0022-5320(62)80011-2

Cited by 25 publications

(9 citation statements)

References 12 publications

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“…In all the sections of scorbutic tissue examined the fibroblastsshowedasignificantswellingandroundingup of the endoplasmic reticulum, whereas in recovery tissue the endoplasmic reticulum had reverted to the configuration observed in normal fibroblasts. There was little evidence of extracellular collagen fibrils in scorbutic tissue, but in several instances an apparently homogeneous extracellular material similar to that previously described (Ross & Benditt, 1962b;Peach, 1962) was observed around the scorbutic fibroblasts. These observations on the dilated endoplasmic reticulum in scorbutic tissue are in agreement with earlier electron-microscopic studies on scurvy and wound healing in the guinea pig (Peach, 1962;Ross & Benditt, 1964).…”

Section: Resultssupporting

confidence: 72%

“…There was little evidence of extracellular collagen fibrils in scorbutic tissue, but in several instances an apparently homogeneous extracellular material similar to that previously described (Ross & Benditt, 1962b;Peach, 1962) was observed around the scorbutic fibroblasts. These observations on the dilated endoplasmic reticulum in scorbutic tissue are in agreement with earlier electron-microscopic studies on scurvy and wound healing in the guinea pig (Peach, 1962;Ross & Benditt, 1964). Further demonstration of the scorbutic nature of the guinea pigs used and an assessment of their recovery from vitamin C deficiency 24h after intraperitoneal administration ofascorbate was given by determining the concentrations of ascorbic acid in the adrenals of the animals.…”

Section: Resultssupporting

confidence: 72%

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Influence of ascorbic acid on ribosomal patterns and collagen biosynthesis in healing wounds of scorbutic guinea pigs

Harwood

Grant

Jackson

1974

Biochemical Journal

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Scorbutic guinea pigs were wounded and the influence of administering ascorbic acid 6 days later was studied with respect to cellular morphology, ribosomal distribution and protein synthesis. Electron-microscopic studies revealed that the dilated endoplasmic reticulum observed in the fibroblasts of scorbutic wound tissue had reverted to a normal configuration 24h after intraperitoneal injection of 100mg of ascorbate. Quantitative determination of the distribution of free and membrane-bound ribosomes indicated a significant increase in membrane-bound ribosomes in wound tissue from ascorbatesupplemented (recovery) animals. Sucrose-density-gradient centrifugation indicated a significant increase in the proportion of large membrane-bound polyribosomes in the range 300-350S and a concomitant decrease in 80S monoribosomes in the ribosome sedimentation profile of recovery tissue. Determination of the synthesis of non-diffusible [3H]hydroxyproline in scorbutic and recovery wounds showed a 3-4-fold stimulation in peptidyl-proline hydroxylation in recovery tissues. Studies carried out in which scorbutic and recovery tissues were incubated with ['4C]leucine indicated that general protein synthesis, as measured by 14C incorporated into non-diffusible material/p,g of DNA, was unaltered by ascorbate supplementation. Similar studies of [3H]proline incorporation suggested that in recovery tissues there was a small but significant increase in [3H]proline incorporated/pg of DNA, which probably represents an increase in protocollagen synthesis. This observation correlates well with the increase seen in recovery tissues of large polyribosomes on which collagen precursor polypeptides are known to be synthesized. Preliminary characterization of the repair collagen synthesized by recovery animals showed it to be a typical Type I collagen having the chain composition (a1)2A2. The extent of glycosylation of the hydroxylysine of the nev%ly synthesized collagen was greater than that reported for either normal guinea-pig dermal collagen or dermal scar collagen.

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Section: Resultssupporting

confidence: 72%

Section: Resultssupporting

confidence: 72%

Influence of ascorbic acid on ribosomal patterns and collagen biosynthesis in healing wounds of scorbutic guinea pigs

Harwood

Grant

Jackson

1974

Biochemical Journal

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“…(c) An increase in the number of free cytoplasmic ribosomes in scorbutic fibroblasts. The first of these, the rounded, separated profiles of the endoplasmic reticulum, was noted earlier (8,38). The characteristic appearance of the cells can be seen in Fig.…”

Section: Wounds Prior To the Administration Of Ascorbic Acidmentioning

confidence: 68%

“…Many of the features of wounds from scorbutic animals have been described previously (8,38). We should like to emphasize three specific observations which are a general feature of all of the changes in the fibroblasts in scurvy.…”

Section: Wounds Prior To the Administration Of Ascorbic Acidmentioning

confidence: 69%

Wound Healing and Collagen Formation

Ross

Benditt

1964

The Journal of Cell Biology

119

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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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“…Chondroblasts showed a marked dissolution of the matrix vesicle and a lack of hyaline droplets. microscopy to elucidate the cause of the haemorrhages (Gore et al, 1968;Peach, 1962). Junctional defects in the endothelium and cytoplasmic disruption due to the lack of precapillary collagen have been described (Gore et al, 1968), but few studies have been directed towards changes occurring in other tissues (Follis, 1958;Peach, 1962).…”

Section: Disorganizationmentioning

confidence: 99%

Ultrastructural studies of vascular and muscular changes in ascorbic acid deficient guinea-pigs

Kim

1977

Lab Anim

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Disorganization of muscle structures such as fragmentation of myofilaments with a loss of contrast in the Z bands, swelling of mitochondria and glycogenic infiltration, was seen in ascorbic acid deficient guinea-pigs. Vacuolar degeneration of external and internal endothelial cell membranes with accompanying dystrophic changes of the surrounding muscle and lack of collagen formation were consistent findings. Chondroblasts showed a marked dissolution of the matrix vesicle and a lack of hyaline droplets.

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An electron optical study of experimental scurvy

Cited by 25 publications

References 12 publications

Influence of ascorbic acid on ribosomal patterns and collagen biosynthesis in healing wounds of scorbutic guinea pigs

Influence of ascorbic acid on ribosomal patterns and collagen biosynthesis in healing wounds of scorbutic guinea pigs

Wound Healing and Collagen Formation

Ultrastructural studies of vascular and muscular changes in ascorbic acid deficient guinea-pigs

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