Journal of Nutrition Vol. 23 No. 1 January 1942, pp. 59-70
Copyright
Criteria of Response in the Bio-Assay of Vitamin E1
Karl E. Mason
Departments of Anatomy, Vanderbilt University School of Medicine, Nashville, Tennessee, and The University of Rochester, School of Medicine and Dentistry, Rochester, N. Y.
- 1. Attempts to evaluate recognized gradations in negative and positive responses to vitamin E administration, based upon the number of live fetuses and the weight of the uterine contents at the sixteenth day of pregnancy in 600 rats used in assay tests, gave results not much superior to those obtained by treating responses as an "all or none" type, except for the recognition of a sub-minimal type of response otherwise classed as negative.
- 2. On the other hand, the presence of two or more viable fetuses in utero at the sixteenth day of pregnancy was found to afford a criterion of positive response essentially equivalent to, and in certain instances more equitable than, that based upon delivery of progeny at term.
- 3. In addition to advantages arising from the shortening of the test period for bio-assay, with the resultant economy of diet and animal care, examination of the uterus at the sixteenth day gives information especially pertinent to critical levels of response and prevents misinterpretation of certain atypical uterine states as negative responses to dose.
1 This investigation was aided by a grant to Vanderbilt University School of Medicine from the Division of Medical Sciences of the Rockefeller Foundation, and by a special grant for technical assistance from the American Academy of Arts and Sciences.
The writer wishes to express his indebtedness to Dr. W. Lamar Bryan for his cooperation and valuable assistance in those phases of this study carried out at Vanderbilt University.
Manuscript received 27 August 1941.