No abstract

Absrruct:The fluoride sensitivity, determined as effect on protein synthesis (incorporation of "C-leucine), of liver and kidney cells in suspension culture was explored. The cells were freshly prepared by collagenase perfusion from rats given drinking water with or without addition of 100 p.p.m. (5.26 mM) fluoride for 9-28 weeks. The fluoride sensitivity of the liver cells from rats given fluoridated water for more than 9 weeks was decreased compared to cells from control rats, whereas the fluoride sensitivity of the kidney cells from fluoride exposed and control rats appeared similar. Fluoride resistance (i.e. decreased sensitivity)may thus develop also in cells in vivo. When exposed to 3 mM NaF for 1 hour the intracellular concentration of fluoride in liver cells from fluoride exposed and control animals was similar.

Various sodium fluoride tablets used for the treatment of osteoporosis were evaluated. The tablets were characterized in vitro by determining the release curves. The serum levels and urinary recovery of fluoride were determined after a single oral dose either of rapidly soluble (conventional), sustained release or enterocoated tablets. The in vivo study showed that administration of sustained release tablets eliminated high serum peaks and prolonged the duration of an elevated serum level as compared to conventional tablets. The biovailability of the fluoride was lower after intake of sustained release and enterocoated tablets, and there was an increase in the interindividual variance of biovailability.