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 Kiorpes, T. C. Articles by Wolf, G. Search for Related Content PubMed PubMed Citation Articles by Kiorpes, T. C. Articles by Wolf, G.

A Plasma Glycoprotein Depressed in Vitamin A Deficiency in the Rat: ₁-Macroglobulin¹

Department of Nutrition and Food Science, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139

Plasma glycoprotein synthesis in normal and vitamin A-deficient rats was investigated by injecting the rats with labeled carbohydrate precursors and then fractionating their plasmas on DEAE-Sephadex. Plasma from deficient rats showed a consistent depression of 30% in the uptake of label into a peak eluting with 0.23 M NaCl. The major component of this peak was identified as the rat ₁-macroglobulin, based on its molecular weight (800,000), its mobility on cellulose acetate electrophoresis and its ability to bind trypsin. Although the ₁-macroglobulin synthesis appeared to be depressed by 30%, its fractional turnover rate was not affected by vitamin A deficiency (t = 18 hours). The trypsin-binding ability of this glycoprotein was used as a comparative measure of its concentration, and the results confirmed that serum levels of this glycoprotein were lower in deficient rats. In severe deficiency, ₁-macroglobulin levels dropped to between 10% and 20% of normal levels.

KEY WORDS: • vitamin A deficiency • ₁-macroglobulin • plasma glycoprotein

¹ This work was supported in part by grants from the National Institutes of Health (AM 8732), the Agency for International Development (TA-C-1285), and the Adelaide Breed Bayrd Foundation. A preliminary report was presented at the 59th Annual Meeting of the Federation of American Societies for Experimental Biology, April, 1975.

Manuscript received 5 March 1976.