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

This Article Full Text (PDF) 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 Google Scholar Google Scholar Articles by Ribaya, J. D. Articles by Gershoff, S. N. Search for Related Content PubMed PubMed Citation Articles by Ribaya, J. D. Articles by Gershoff, S. N.

Effects of Hydroxyproline and Vitamin B-6 on Oxalate Synthesis in Rats

Tufts University, School of Nutrition, Medford, MA 02155

Relationships among dietary hydroxyproline (HP), vitamin B-6 and endogenous oxalate formation have been studied. In the absence of HP, urinary oxalate excretion was greatest among rats fed vitamin B-6-deficient diets. Supplementation of rat diets with 5.2% HP markedly increased the oxalate excretion of rats fed 0, 0.2 or 10 mg of vitamin B-6 per 100 g of diet, the increases being 2-, 19- and 15-fold respectively. The metabolism of several ¹⁴C-labeled oxalate precursors was altered in vitamin B-6-deficient rats. The feeding of HP and different levels of vitamin B-6 also altered their metabolism. The feeding of HP to vitamin B-6-deficient rats resulted in a decrease in the amount of ¹⁴C-oxalate formed from injected ¹⁴C-labeled glycine, glycolate or glyoxylate. In contrast, HP feeding to rats given 0.2 mg of vitamin B-6 per 100 g, resulted in a marked increase in oxalate formation from injected ¹⁴C-glycolate, as well as a decrease in respiratory ¹⁴CO₂ from injected ¹⁴C-labeled glycolate and glyoxylate. HP feedings did not significantly alter the metabolism of these two injected compounds to oxalate or CO₂ among rats fed the higher level of vitamin B-6, although some elevation of oxalate formation from glycolate was noted. HP feeding reduced the growth rates of all the rats, but growth depression was greatest in the vitamin B-6-deficient group.

KEY WORDS: • vitamin B-6 • hydroxyproline • oxalate synthesis

Manuscript received 2 January 1981.