GASTRIC AND INTESTINAL-ABSORPTION OF MONOFLUOROPHOSPHATE AND FLUORIDEIN THE RAT

This paper reports data indicating that, in the rat, sodium monofluoro phosphate (MFP, CAS 10163-15-2) is absorbed without hydrolysis through the stomach. This phenomenon and the fact that MFP binds to plasma gl obulins produce a prompt increase in protein-bound MFP concentration, significantly greater than the increase in plasma ultrafilterable fluo ride. Intestinal absorption of MFP was investigated with the isolated duodenal loop in situ. The drug was hydrolyzed to fluoride at the inte stinal lumen with a rate of approx. 3 times greater than that for fluo ride absorption. After filling the duodenal loop with a MFP solution, ultrafiltrable fluoride accounts for the increase in plasma fluoride c oncentration, with no evidence of protein-bound MFP. This report also includes analytical techniques for the measurement of MFP in test solu tions and and plasma.