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Abstract
Zinc-deficient rats have very low plasma vitamin A levels in spite of adequate liver
vitamin A stores. A study was conducted to explore the effects of zinc deficiency
on the metabolism of retinol-binding protein (RBP), the plasma transport protein for
vitamin A. The plasma RBP level of zinc-deficient rats was only 14 ± 2 μg per milliliter
In contrast, the plasma RBP level was 50 ± 2 μg per milliliter in control rats fed
ad libitum on a zinc-sufficient diet and 36 ± 1 μg per milliliter in a zinc-sufficient
group pair-fed with the zinc-deficient rats. Moreover, the liver RBP levels of the
zinc-deficient group were only about 55 to 60 per cent of the levels of either the
ad libitum or pair-fed control animals. The data suggest that zinc deficiency interferes
with the synthesis of RBP by the liver and probably with the synthesis of some other
plasma proteins as well. The low plasma vitamin A levels seen in zinc deficiency can
be attributed to an impaired ability of the deficient rat to mobilize vitamin A from
its liver in the form of the retinol-RBP complex.
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Article info
Publication history
Accepted:
June 21,
1974
Received:
February 21,
1974
Footnotes
☆This work was supported in part by Grants AM-05968, HL-14236 (SCR), and 1 RO1 AM 15703 from the National Institutes of Health.
Identification
Copyright
© 1974 Published by Elsevier Inc.