A plasma glycoprotein depressed in vitamin A deficiency in the rat: alpha 1-macroglobulin.
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 alpha1-macroglobulin, based on its molecular weight (800,000), its mobility on cellulose acetate electrophoresis and its ability to bind trypsin. Although the alpha1-macroglobulin synthesis appeared to be depressed by 30%, its fractional turnover rate was not affected by vitamin A deficiency (t 1/2 = 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, alpha1-macroglobulin levels dropped to between 10% and 20% of normal levels.
D000818:Animals; D005944:Glucosamine / Q000378:metabolism; D006023:Glycoproteins / Q000096:biosynthesis / Q000097:blood*; D008297:Male; D008358:Mannose / Q000378:metabolism; D008970:Molecular Weight; D011485:Protein Binding; D051381:Rats; D014357:Trypsin / Q000378:metabolism; D014802:Vitamin A Deficiency / Q000097:blood*; D000511:alpha-Macroglobulins / Q000378:metabolism*
D006023:Glycoproteins; D000511:alpha-Macroglobulins; D014357:Trypsin; D005944:Glucosamine; D008358:Mannose