Fluoride Action Network


1. The effect of sodium fluoride (NaF) on gastrointestinal tracts of rats was investigated. 2. Blood flow rate in rat stomach mucosa was only 30% of the initial rate during 30-60 min after a single oral dose (300 mg/kg) of NaF. 3. The addition of NaF (final NaF concentration: 50 and 100 ppm) in vitro gave the reduction of 10 and 28%, respectively, of initial free calcium ion levels in rat blood. 4. These results indicate that oral ingestion of excess amount of NaF caused dilatation of blood vessel and greatly decreased blood flow rate to accumulate the circulating blood in the mucosa of gastrointestinal tract to cause redness.