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 Fell, D. Articles by Steele, R. D. Search for Related Content PubMed PubMed Citation Articles by Fell, D. Articles by Steele, R. D.

Enhancement of Histidine and One-Carbon Metabolism in Rats Fed High Levels of Retinol¹

Department of Nutrition, Rutgers University, New Brunswick, NJ 08903

Histidine metabolism was studied in rats fed 10% casein diets supplemented with 1000 IU of retinol/g concurrent with or previous to exposure to high levels of dietary histidine (1% or 2%). When a retinol-supplemented 10% casein + 1% histidine diet was fed ad libitum for 21 days, urinary excretion of formininoglutamic acid (FIGLU) was decreased by 50–70% over the entire period and plasma histidine was reduced by 30–70% for 16 days compared to rats receiving 10% casein + 1% histidine with normal levels of retinol. Rats pretreated for 10 days with a 10% casein diet supplemented with high levels of retinol oxidized 30% more L-[ring-2-¹⁴C]histidine to ¹⁴CO₂ and excreted 76% less of the administered dose as urinary FIGLU compared to control rats not pretreated with high levels of retinol. Depressions in grwoth due to supplementation of a 10% casein diet with 1% histidine were also partially alleviated in rats that were first pretreated with retinol. Activities of histidase, urocanase, and formiminoglutamic acid formiminotransferase (FIGLU transferase) were unaffected by retinol supplementation. The results suggest that retinol supplementation enhances histidine catabolism by exerting a change on one-carbon metabolism.

KEY WORDS: • retinol supplementation • formiminoglutamic acid • histidine • one-carbon metabolism

¹ This research was supported by the New Jersey Agricultural Experiment Station, project 14421. This is a paper of the journal series, New Jersey Agricultural Experiment Station. A preliminary report of this work has appeared in Fed. Proc. 40, 1685 (1981).

² To whom reprint requests should be sent.

Manuscript received 24 August 1981.