P. H. Phillips

Dental Caries in the Cotton Rat IX. Effect of Milk Rations

Summary Data on growth and caries indices of cotton rats fed various mill, rations were secured from these experiments The data indicate that milk is piotective againit dental caries in the cotton rat. Previous findings of Zero scores in animals fed only liquid mill were confirmed. Animals reciving milk to which sucrose, glucose or dextri-maltose had been added exhibited low caries scores as compared with controls on a cariogenic dry ration. These sugars will producecaries when fed in dry ration. The caries indices of animals receivinq approximately one-third of their caloric intake as liquid millk and the remainder as the cariogenic ration 8.02 were less by 50% than those of litter-mate controls not receiving milk.

Development of fluorine toxicosis in the rabbit.

Summary and Conclusions A study of growing rabbits fed a complete diet supplemented with various levels and forms of fluorine has been made. When levels of fluorine were included in the ration above .021% rabbits in 4 months developed a symptomatology indicating the development of fluorine toxicosis. Growth was retarded, stiffness of the joints occurred, and pronounced changes in the teeth and structure of the bone were encountered. Fluorine was concentrated in the skeleton, and it appears from these data that the rabbit can withstand a storage of fluorine up to about 5,000 ppm without affecting such physiological processes as growth, health, normal teeth, and bone. In this species the fluorine of raw rock phosphate produced as toxic results, or more so, as an equivalent level of sodium fluoride borne fluorine.

Uric acid diabetes in the rat.

Summary Uric acid was non-diabetogenic in methionine and sodium deficient rats. Methionine deficiencies induced by 9% casein, α-protein and oxidized casein rations lowered the liver glutathione but did not lower the blood glutathione. The superimposing of a methionine deficiency on a sodium deficiency (low blood glutathione) did not cause a simultaneous decrease in the blood and liver glutathione of the rat.

Effect of high fat diet on the potassium deficiency syndrome in the rat.

Summary A diet containing 0.03% potassium and 20% corn oil produced a greater incidence and extent of the myocardial necrosis and fibrosis and dilatation of renal tubules typical of potassium deficiency than did an isocaloric, 5% corn oil diet containing the same amount of potassium when the 2 diets were pair fed. No statistically significant differences were observed in other criteria of potassium deficiency.

Serum fluoride in the chick.

Summary The serum fluoride level of the young chick has been shown to be elevated from a normal range of under 0.2 ppm F to over 4.0 ppm F when 900 ppm F is added to the diet. The response is related to the amount of fluoride in the diet, and is dependent upon the composition of the diet. This large increase in serum fluoride in the chick is in sharp contrast to the efficient homeostatic fluoride control noted in most species.

Effect of deficiencies of sodium and potassium on motility of the intestine of the rat.

Summary Maintenance of adult female albino rats on a diet containing 0.005% potassium for 6 weeks resulted in a 50% decrease in intestinal propulsive motility. Reduction of the sodium content of this diet from 0.25% to 0.005% did not result in an increase in intestinal motility. Feeding a diet containing 0.005% sodium and 0.5% potassium did not alter the intestinal propulsive motility of the albino rats when compared with observations of control animals on a diet containing 0.5% potassium and 0.25% sodium.

Unsaturated Fatty Acids of Blood Serum from Pigs with and without Parakeratosis.

Summary As a part of nutritional studies on parakeratosis in swine, the content of essential fatty acids in blood serum of pigs with and without parakeratosis was determined. It is concluded that low levels of the essential fatty acids in the blood are not associated with the development of parakeratosis.

Stimulation of Peristalsis in the Potassium Deficient Rat by Acetyl-β-Methylcholine.

Summary Acetyl-β-methylcholine was observed to stimulate intestinal motility in potassium deficient rats but did not affect the intestinal motility of rats receiving complete diets.