Hostname: page-component-7479d7b7d-rvbq7 Total loading time: 0 Render date: 2024-07-08T09:58:02.119Z Has data issue: false hasContentIssue false

Neonatal role of milk folate-binding protein: studies on the course of digestion of goat's milk folate binder in the 6-d-old kid

Published online by Cambridge University Press:  24 July 2007

D. N. Salter
Affiliation:
National Institute for Research in Dairying, Shinfield, Reading, Berkshire RG2 9AT
A. Mowlem
Affiliation:
National Institute for Research in Dairying, Shinfield, Reading, Berkshire RG2 9AT
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

1. Groups of kids were reared from birth to 5 d on goat's milk. On the 6th day five of the kids received by bottle a morning feed of goat's milk with [3H]folic acid added to saturate the folate-binding proteins (FBP) (Expt 1); three kids received raw goat's milk containing only the endogenous folate and hence a large surplus folate-binding capacity (FBC) (Expt 2). The contents of the stomach, duodenum, jejunum and ileum were recovered by washing out 1·5 h after feeding (Expt 1) or at 0·5, 1 and 3·5 h after feeding (Expt 2).

2. Recovery of [3H]folic acid 1·5 h after feeding (Expt 1) in all segments was 58·4%, mainly in a soluble form, most of this being in the stomach (37·0%) and ileum (14·3%). No surplus FBC was found in any gut segment. Sephadex G-75 chromatography of the soluble fractions of the contents of the various gut segments showed that [3H]folic acid remained bound to FBP throughout the stomach and small intestine. The bound [3H]folic acid exhibited a molecular weight of 81000 in stomach contents, similar to that in the milk feed, presumably representing an aggregated form of the FBP, whereas in the intestinal contents its molecular weight was 39000 indicating dissociation to monomer due to dilution in the recovery process.

3. In Expt 2, the total recovery of free FBP in all four gut segments was 67, 54 and 23% respectively at 0·5, 1 and 3·5 h after the milk feed, and the distribution of FBP along the gut at 1 h was similar to that of [3H]folic acid-labelled FBP at 1·5 h in Expt 1. In mature goat's milk the endogenous 5-methyltetrahydrofolate was shown to be associated with species of molecular weight 80000 and 38000.

4. The results indicate that goat's-milk FBP is relatively resistant to digestionby gastric and intestinal enzymes in vivo in the kid and survives along the length of thesmall intestine.

5. The implications of the findings are discussed in relation to the possible influence of FBP on uptake of folate by mucosal cells and their relevance to neonatal folate nutrition.

Type
Research Article
Copyright
Copyright © The Nutrition Society 1983

References

Andrews, P. (1964). Biochemical Journal 91, 222233.Google Scholar
Aumaitre, A. (1972). World Review of Animal Production 8 (3), 5468.Google Scholar
Colman, N., Hettiarachchy, N. & Herbert, V. (1981). Science 211, 14271429.CrossRefGoogle Scholar
Foltman, B., Jensen, A. L., Lønblad, P., Smidt, E. & Axelsen, N. H. (1981). Comparative Biochemistry and Physiology 68B, 913.Google Scholar
Ford, J. E. (1974). British Journal of Nutrition, 31, 243257.Google Scholar
Ford, J. E., Knaggs, G. S., Salter, D. N. & Scott, K. J. (1972). British Journal of Nutrition 27, 571583.CrossRefGoogle Scholar
Ford, J. E., Law, B. A., Marshall, V. M. E. & Reiter, B. (1977). Journal of Pediatrics 90, 2935.Google Scholar
Ford, J. E., Salter, D. N. & Scott, K. J. (1969). Journal of Dairy Research 36, 435446.Google Scholar
Ghitis, J. (1967). American Journal of Clinical Nutrition 20, 14.Google Scholar
Gregory, J. F. (1982). Journal of Nutrition 112, 13291338.Google Scholar
Hansen, S. I., Holm, I. & Lyngbye, I. (1977). Scandinavian Journal of Clinical and Laboratory Investigation 37, 363367.CrossRefGoogle Scholar
Herbert, V. (1961). Journal of Clinical Investigation 40, 8191.CrossRefGoogle Scholar
Kamen, B. A. & Caston, J. D. (1974). Journal of Biological Chemistry 250, 22032205.CrossRefGoogle Scholar
Laskowski, M. & Laskowski, M. (1951). Journal of Biological Chemistry 190, 563573.Google Scholar
Leslie, G. I. & Rowe, P. B. (1972). Biochemistry 11, 16961703.Google Scholar
Pedersen, T. B., Svendsen, I. B., Hansen, S. I., Holm, I. & Lyngbye, I. (1980). Carlsberg Research Communications 45, 161166.Google Scholar
Rothenberg, S. P. (1970). Proceedings of the Society for Experimental Biology and Medicine 133, 428432.Google Scholar
Rubinoff, M., Schreiber, C. & Waxman, S. (1977). Federation of European Biochemical Societies Letters 75, 244248.CrossRefGoogle Scholar
Salter, D. N., Ford, J. E., Scott, K. J. & Andrews, P. (1972). Federation of European Biochemical Societies Letters 20, 302306.Google Scholar
Salter, D. N., Scott, K. J., Slade, H. & Andrews, P. (1981). Biochemical Journal 193, 469476.Google Scholar
Spector, R. (1977). Journal of Biological Chemistry 252, 33643370.CrossRefGoogle Scholar
Waxman, S. (1977). In Advances in Nutritional Research vol. 1, pp. 165178 [Draper, H. H., editor]. New York: Plenum Publishing Corporation.Google Scholar
Waxman, S. & Schreiber, C. (1973). Blood 42, 291301.CrossRefGoogle Scholar
Zamierowski, M. M. & Wagner, C. (1977). Journal of Biological Chemistry 252, 933938.CrossRefGoogle Scholar