Professionals Urge End to Water Fluoridation

Below abstract indicates fluoride damages mito in human kidney cells.

Fluoride ion toxicity in human kidney collecting duct cells.

BACKGROUND: Several halogenated anesthetics induce a urinary
concentrating defect, partly related to fluoride ion toxicity in
collecting duct cells. The aim of this study was to investigate the
effects of fluoride ion in human kidney cells. METHODS: Immortalized
human collecting duct cells were used. In a first set of experiments,
the toxicity threshold concentration was determined by exposing cell
cultures for 24 h to increasing concentrations of fluoride ion in the
medium: 0, 1, 5, and 10 mM. The second set of experiments was a time-
effect study in which cells were exposed to 5 mM fluoride for 2, 6,
and 24 h. Assessment of toxicity was based on several endpoints: cell
number, protein content, (3)H-leucine incorporation in newly
synthesized proteins, extracellularly released lactate dehydrogenase,
Na-K-ATPase pump activity, and electron microscope studies. RESULTS:
After 24 h of exposure, fluoride ion decreased cell number (-23%,
P0.05), total protein content (-30%, P0.05) and increased lactate
dehydrogenase release (+236%, P0.05) at a threshold concentration of
5mM. Fluoride ion also inhibited Na-K- ATPase activity at 5 mM (-58%,
P0.05). Major morphologic alterations of mitochondria, including
crystal formation, were detected from 1 mM fluoride concentration.
Time-effect studies showed that, after only 6 h of exposure at 5 mM,
fluoride decreased cell number (-13%, P0.05), (3)H-leucine
incorporation (-48%, P0.05), and Na-K-ATPase activity (- 20%, P0.05)
and increased lactate dehydrogenase release (+145%, P0.05). Crystal
deposits in mitochondria again were a more sensitive marker of cell
injury, detectable after only 2 h of exposure. CONCLUSIONS: these
results suggest that the mitochondrion is a target of fluoride
toxicity in human collecting duct cells, and its alteration is partly
responsible for the sodium and water disturbances observed in
patients. PMID: 8602675