Silicon deprivation decreases collagen formation in wounds and bone, and ornithine transaminase enzyme activity in liver

Biol Trace Elem Res. 2002 Dec;89(3):251-61. doi: 10.1385/bter:89:3:251.


We have shown that silicon (Si) deprivation decreases the collagen concentration in bone of 9-wk-old rats. Finding that Si deprivation also affects collagen at different stages in bone development, collagen-forming enzymes, or collagen deposition in other tissues would have implications that Si is important for both wound healing and bone formation. Therefore, 42 rats in experiment 1 and 24 rats in experiment 2 were fed a basal diet containing 2 or 2.6 microg Si/g, respectively, based on ground corn and casein, and supplemented with either 0 or 10 microg Si/g as sodium metasilicate. At 3 wk, the femur was removed from 18 of the 42 rats in experiment 1 for hydroxyproline analysis. A polyvinyl sponge was implanted beneath the skin of the upper back of each of the 24 remaining rats. Sixteen hours before termination and 2 wk after the sponge had been implanted, each rat was given an oral dose of 14C-proline (1.8 microCi/100 g body wt). The total amount of hydroxyproline was significantly lower in the tibia and sponges taken from Si-deficient animals than Si-supplemented rats. The disintegrations per minute of 14C-proline were significantly higher in sponge extracts from Si- deficient rats than Si-supplemented rats. Additional evidence of aberrations in proline metabolism with Si deprivation was that liver ornithine aminotransferase was significantly decreased in Si-deprived animals in experiment 2. Findings of an increased accumulation of 14C-proline and decreased total hydroxyproline in implanted sponges and decreased activity of a key enzyme in proline synthesis (liver ornithine aminotransferase) in Si-deprived animals indicates an aberration in the formation of collagen from proline in sites other than bone that is corrected by Si. This suggests that Si is a nutrient of concern in wound healing as well as bone formation.

MeSH terms

  • Animals
  • Collagen / biosynthesis*
  • Diet
  • Femur / injuries
  • Femur / metabolism*
  • Hydroxyproline / analysis
  • Implants, Experimental
  • Liver / enzymology*
  • Male
  • Ornithine-Oxo-Acid Transaminase / metabolism*
  • Polyvinyls / chemistry
  • Proline / administration & dosage
  • Rats
  • Rats, Sprague-Dawley
  • Silicon / administration & dosage
  • Silicon / deficiency*
  • Wound Healing / drug effects*


  • Polyvinyls
  • ivalon sponge
  • Collagen
  • Proline
  • Ornithine-Oxo-Acid Transaminase
  • Hydroxyproline
  • Silicon