The Effect of Calcium Carbonate and Sodium Bicarbonate on the Toxicity of Gossypol»

In a previous study of the influence of certain dietary constituents on the response of rats to gossypol ingestion {2) ^ the authors showed that the toxicity of diets containing known amounts of gossypol was materially reduced when the diets were made basic by the addition of calcium carbonate and sodium bicarbonate. When the diets were made acidic by the addition of calcium chloride, only indirect evidence of a slight decrease in toxicity was obtained. Decreased toxicity was observed also when the protein content of the diet was increased from 13 percent to 35 percent. The conclusion was drawn that diets of high protein content and basic diets of high calcium content are favorable to the detoxication of gossypol. Considerable importance is attached to the results since calcium and protein are variable ingredients in diets used for the bio-assay of gossypol. The importance of these constituents in feeding cottonseed products to livestock has not been fully determined, although the value of supplementary protein in cottonseed-meal rations for pigs has recently been pointed out by Robison (5). In view of the favorable results obtained with sodium bicarbonate and calcium carbonate, it was deemed desirable to determine the proportion of these salts which would offer the greatest degree of protection against gossypol injury and to determine the value of each salt in the presence of moderate amounts of thç other, as the principal elements of both are requisite for a normal nutritive condition. The present paper reports the results of this study. The results of other experiments, in which calcium altered the inhibiting effect of gossypol on the hydrolysis of fat by lipase, are also reported. The results of these studies are offered as further evidence of the important part played by calcium in the detoxication of gossypol.