Effect of hypervitaminosis A on tongue muscles of the rat. A morphometric study.

Daily administration of 200 I.U. vitamin A/gram body weight to rats, for a period of 10 days, causes generalized hypertrophy of the tongue muscles. The data were confirmed with morphometric techniques, consisting of increased cytoplasm and decreased nuclei and empty spaces, obtained by the Chalkley technique, nuclei of similar volume, obtained with the use of karyometry, and larger areas of cross-sections of muscle fibers.