The effect of excess vitamin A on the oxygen consumption of young female rats

✍ Scribed by Sampson, Myra M. ;Carpenter, Esther ;Wight, Roland

• Publisher: John Wiley and Sons
• Year: 1962
• Tongue: English
• Weight: 494 KB
• Volume: 151
• Category: Article
• ISSN: 0022-104X
• DOI: 10.1002/jez.1401510309

✦ Synopsis

The purpose of the following experiments was to determine the effect of different levels of excess vitamin A in the diet on the activity of the thyroid gland as indicated by determinations of oxygen consumption in relation to body weight.

Methods

Twenty-seven female rats of the Sprague-Dawley strain were used in sets of three litter-mates each. Different sets were run at different times. Initial ages of the sets ranged from 41 to 48 days. The weight range was from 116 to 157 gm. In individual sets the weight variation was from 1 to 20 gm.

All animals were supplied with a purified basal diet with tri-weekly additions of adequate vitamin supplements (table ). The amount of vitamin A included was between 3 and 6 I.U. daily per gram of body weight. After a week on this diet, the experimental rat of a set was given additional vitamin A orally in the form of palmitate, six times a week, by means of a calibrated pipette. Initial doses of 25,000 I.U. per day per rat were continued for 38 and 42 days in sets L and N when the experiments were terminated. This dosage provided between 100 and 200 I.U.