Fluoride Action Network

Two hundred and twenty-six white rats were given a diet containing 0.05 per cent sodium fluoride (226 ppm) for periods ranging from 3 to 56 days. It was established that changes in the kidneys occurred regularly after 21-28 days on the diet.

The kidney changes consisted primarily in dilatation of the Henle loops in the juxtacortical area of the medulla, soon followed by a flattening of the epithelium in the convoluted tubules in the cortex and a distention of the tubules, possibly due to some kind of ‘stop’ in the Henle loops.