QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) An erratum has been published An erratum has been published Purchase Article View Shopping Cart Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Peters, J. P. Articles by Elliot, J. M. Search for Related Content PubMed PubMed Citation Articles by Peters, J. P. Articles by Elliot, J. M.

Effects of Cobalt or Hydroxycobalamin Supplementation on Vitamin B-12 Content and (S)-Methylmalonyl-CoA Mutase Activity of Tissue from Cobalt-Depleted Sheep

Department of Animal Science, Cornell University, Ithaca, NY 14853-0281

Lambs (3 months of age) and ewes were fed ad libitum a depletion diet low in cobalt (0.06 ppm) for 7 months. Five sheep were then assigned to each of the following treatments: 330 µg hydroxocobalamin (OH-B-12) intramuscularly, 2.7 mg cobalt (Co) orally, and no supplementation (no suppl). Treatments were given on alternate days for 9 weeks. Both forms of resupplementation increased the animal's body weight at slaughter compared to nonsupplementation, while absolute weights and protein concentrations of brain, liver, heart, rumen and kidney were not affected. Supplementation increased concentrations of vitamin B-12 in all tissues; Co and OH-B-12 being equally effective in brain and ruminal mucosa, whereas OH-B-12 had a greater effect in heart, liver and kidney. The greatest concentrations of vitamin B-12 were observed in liver (2630 ± 160, 1500 ± 230 and 60 ± 20 ng/g wet liver for OH-B-12, Co and no suppl groups, respectively) and kidney, although liver contained the greatest absolute amount of vitamin B-12. Activity of (S)-methylmalonyl-CoA mutase, assayed in the presence of added coenzyme B-12, was not increased with resupplementation except in kidney. The activity of mutase without coenzyme added in vitro was correlated with tissue content of vitamin B-12. Through this study we demonstrate that in sheep tissue the activity of (S)-methylmalonyl-CoA mutase is limited by coenzyme rather than enzyme per se. Liver possesses the greatest quantitative activity of mutase and is most responsive to alterations of vitamin B-12 status.

KEY WORDS: • vitamin B-12 • (S)-methylmalonyl-CoA mutase • cobalt

¹ Present address: Experimental Agricultural Sciences, Upjohn Company, Kalamazoo, Michigan 49001.

² Reprint requests should be sent to this author.

Manuscript received 27 June 1983.

This article has been cited by other articles:

				B. Graulet, J. J. Matte, A. Desrochers, L. Doepel, M.-F. Palin, and C. L. Girard Effects of Dietary Supplements of Folic Acid and Vitamin B12 on Metabolism of Dairy Cows in Early Lactation J Dairy Sci, July 1, 2007; 90(7): 3442 - 3455. [Abstract] [Full Text] [PDF]