Limitation of Fluorine Toxicosis in the Rat with Aluminum Chloride. ∗

Abstract

Fluorine fed in low concentration has been shown to cause defective teeth in guinea pigs, rats, dogs, and cattle. In higher concentrations it causes inferior reproduction, poor bones and inferior growth or death. 1 Recently it has been shown that mottled enamel of human teeth is caused by the toxic action of fluorides present in drinking water. 2

This is a report of some work done in the search for a substance that would limit the toxic action of fluorine. Salts of lanthanum, cerium, thorium, and boron, which form insoluble or complex fluorides were found to give either no protection or, as in the case of lanthanum, only slight protection. Aluminum chloride was found to inhibit to a large extent the toxic effect of fluorine.

The basal diet used was as follows: yellow corn meal 30.0 parts, ground whole wheat 30.0 parts, whole milk powder 30.0 parts, linseed meal 5.0 parts, alfalfa meal 3.0 parts, and wheat germ 1.0 part.

Fluorine was added to this diet as a solution of sodium fluoride. Aluminum chloride was also added in solution. When both were added the solutions were combined.

Sodium fluoride was fed in 2 concentrations, 0.025 and 0.1% of the diet. Aluminum chloride was fed in concentrations of 0.5% and 2.0%, which is equivalent to 0.056 and 0.224% aluminum respectively.

Effect upon Growth. Sodium fluoride fed at a level of 0.025% of the diet had no effect on the rate of growth. Animals fed the diet containing 0.1% sodium fluoride grew at approximately two-thirds the normal rate. By adding 0.056% aluminum to the diet as the chloride, normal growth was obtained.

Since it has been shown that calcium fluoride is less toxic to growth than sodium fluoride 3 the effect of calcium salts added in place of the aluminum was also studied.