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 Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Guerrant, N. B. Search for Related Content PubMed Articles by Guerrant, N. B.

Influence of Age and of Vitamin A Intake on the Storage of Vitamin A in the Liver of the Rat¹

Department of Agricultural and Biological Chemistry, The Pennsylvania State College, State College, Pennsylvania

A study was made of the effects of age and of the vitamin A intake of the rat on vitamin A storage as indicated by the vitamin A content of the liver, this content being determined on the nonsaponifiable extract of the liver by means of the antimony trichloride method. The results obtained during the course of this study were as follows:

1. The liver of the normal newly-born rat contained very little vitamin A.

2. The concentration of vitamin A in the liver of the nursing rat more than doubled during the first 7 days of postnatal life and then remained relatively constant during the remainder of the nursing period.

3. The amount and the concentration of vitamin A in the liver of the normal weanling rat increased rapidly throughout the period of rapid growth and reached a maximum concentration when the rat was about 170 days old. Beyond this age, additional vitamin A was stored but the concentration per gram of liver remained relatively constant.

4. The amount of vitamin A stored in the livers of depleted rats depended upon the intake, but no marked increase in concentration of hepatic vitamin A occurred until the intake was more than sufficient to promote optimum growth. Below this level of intake, increase in vitamin A storage as indicated by increased concentration was largely hidden by increase in weight of liver.

5. With vitamin A intakes in excess of that required for optimum growth, liver storage increased in proportion to the intake until a daily intake of 17,600 U.S.P. units was reached. Intakes of vitamin A in excess of this amount did not result consistently in additional vitamin A storage when fed under the conditions of these experiments.

6. Optimum growth was brought about in depleted rats when 44 U.S.P. units of vitamin A were fed daily, whereas daily dosages in excess of 8,800 U.S.P. units had a definite depressive effect on the growth rate.

The effects on liver storage of vitamin A in the rat resulting from ingestion of other types of experimental diets are presented and discussed.

Manuscript received 30 August 1948.