Figure 1. Acute excess of I⁻ inhibits I⁻ uptake in rat thyroid glands.

A, The percentage of I⁻ uptake by the thyroid gland as a function of treatment, with a range of three high doses (100, 1000, and 10 000 μg/d) of I⁻ over a period of 6 days. The percentage of I⁻ uptake was expressed as a mean ± SEM (n ≥ 3) (P < .05). B, I⁻ uptake in the thyroid glands of rats that received excess I⁻ (100 μg) for 5 hours, 1 day, or 6 days. This was measured and plotted as the percentage of I⁻ uptake as compared with thyroid glands from rats without excess I⁻. The data were expressed as the mean ± SEM (n ≥ 3).