Excessive ingestion of iodide by the rat during pregnancy and lactation. Effects on ribonucleic acid transcription in the pups brain.

The effects of an excessive ingestion of iodide by the rat during pregnancy and lactation on the transcription of RNA were studied in the brain of the pups at 10, 15 and 20 days of age. Cerebral weight, DNA content and synthesis of heterogeneous RNA were not affected during the period studied. The activity of endogenous RNA polymerase I, alpha-amanitin resistant, measured in isolated cell nuclei was significantly reduced in twenty day old rats. Similar conditions meaningfully diminished body weight at the same age.