![[Feedback]](/icons/banner/feedbackACT.gif){kind=icon}
![[For Subscribers]](/icons/banner/subscriberACT.gif){kind=icon}
![[Archive]](/icons/banner/archiveACT.gif){kind=icon}
![[Search]](/icons/banner/searchACT.gif){kind=icon}
![[Contents]](/icons/banner/tocACT.gif){kind=icon}
|
|
|
|
|
||
Manuscript received 26 December 1996. Initial reviews completed 23 February 1997. Revision accepted 23 April 1997.
Laboratoire de Nutrition et Sécurité Alimentaire, INRA, 78352 Jouy en Josas cedex, France
We have demonstrated that alkaline phosphatase activity and collagen synthesis are dose-dependently stimulated by ascorbic acid in differentiated pig osteoblasts. In this study we further examined the relationship between ascorbic acid and bone metabolism by feeding young pigs large amounts of ascorbic acid. Three groups of seven 47-d-old pigs were given no ascorbic acid supplement (control), 500 (500 AA) or 1000 (1000 AA) mg ascorbic acid/kg diet for 4 mo. Calcium and P absorption and retention were evaluated by a 14-d balance trial immediately before killing in control and 1000 AA groups only (n = 6). Bones were collected at death and the bone ash and bending moment (three-point bending test) determined. Various plasma and urine indices of bone metabolism, especially those reflecting collagen degradation (hydroxyproline, deoxypyridinoline) and synthesis (carboxyterminal propeptide of type I collagen) were monitored. The plasma ascorbic acid concentrations increased with time and paralleled the dietary concentrations (P < 0.01). The Ca and P balances and the bone ash and bending moments in the ascorbic acid-supplemented pigs did not differ from those of the controls. Plasma osteocalcin was elevated (P < 0.05), whereas the other bone formation markers, alkaline phosphatase and carboxy terminal propeptide of type I collagen, were not affected by ascorbic acid. The plasma concentrations of Ca, P and 1,25-dihydroxycholecalciferol did not differ among the three groups. The unaffected urinary excretion of deoxypyridinoline and hydroxyproline in the ascorbic acid-supplemented pigs indicates that ascorbic acid does not alter bone resorption. Thus, high intakes of ascorbic acid have no positive influence on bone metabolism and bone characteristics in pigs. The in vivo long-term effects do not correlate with the short-term in vitro effects previously reported.
Key words: ascorbic acid, pigs, bone, collagen markers, osteocalcin.
This article has been cited by other articles:
|
|
 |
|
  J. K. Patterson, X. G. Lei, and D. D. Miller The Pig as an Experimental Model for Elucidating the Mechanisms Governing Dietary Influence on Mineral Absorption Experimental Biology and Medicine, June 1, 2008; 233(6): 651 - 664. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. C. Mollard, H. R. Kovacs, S. C. Fitzpatrick-Wong, and H. A. Weiler Low Levels of Dietary Arachidonic and Docosahexaenoic Acids Improve Bone Mass in Neonatal Piglets, but Higher Levels Provide No Benefit J. Nutr., March 1, 2005; 135(3): 505 - 512. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. A. Weiler and S. C. Fitzpatrick-Wong Modulation of Essential (n-6):(n-3) Fatty Acid Ratios Alters Fatty Acid Status but Not Bone Mass in Piglets J. Nutr., September 1, 2002; 132(9): 2667 - 2672. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. Eklou-Kalonji, E. Zerath, C. Colin, C. Lacroix, X. Holy, I. Denis, and A. Pointillart Calcium-Regulating Hormones, Bone Mineral Content, Breaking Load and Trabecular Remodeling Are Altered in Growing Pigs Fed Calcium-Deficient Diets J. Nutr., January 1, 1999; 129(1): 188 - 193. [Abstract] [Full Text] [PDF]
|
|
