Effect of iodide on mucociliary transport in anesthetized dogs.

Using a recently described tracer method, we determined tracheal transport velocity (TTV) before and after intravenous administration of 10 ml of 0.1% sodium iodide (NaI) in anesthetized dogs. In nine experiments in hydrated dogs TTV did not change significantly after NaI therapy (mean change -1.3 mm/min +/- 1.8 SEM; P greater than 0.10). In 10 experiments in dehydrated dogs TTV increased significantly after NaI therapy (mean change 6.1 mm/min +/- 2.1; P less than 0.02). In 13 control experiments in dehydrated dogs not given NaI, TTV did not change significantly (mean change 1.4 mm/min +/- 1.1; P greater than 0.2). The increase in TTV in the dehydrated dogs treated with NaI was significantly greater than the change in TTV in the dehydrated dogs not given NaI (P less than 0.025). Previous studies have shown a dehydration-induced depression of TTV which was reversed by rehydration. These findings suggest that iodides improve mucociliary transport function in the dehydrated state but not the hydrated state and that this improvement is comparable to that following rehydration.