Lithium chloride (LiCl, 1.43 ±changes in the total amount of soluble collagen, 0.13 mEq/k/day) was administered in distilled the rate of collagen resorption under standardized water to 13 adult female rats for 40 days; 6 rats conditions in vitro, or the rate of collagen forma-served as controls. LiCl had no effect on theserumtion. Serum lithium rose to 0.42 ± 0.10 mEq/1 total calcium and inorganic phosphorus or on and bone lithium content to 29/μg/g wet weight. metaphyseal bone composition or collagen metabo-The data fail to demonstrate any effect of lithium lism. There were no significant changes in the on female rat bone composition or metabolism percentage bone wet weight of mineral salts,ni doses which are many times the usual human organic matrix, or fat and water; there were no prophylactic dose of 0.2–0.4 meq/k/day and ad-changes in the content per unit wet weight of ministered under the experimental conditions calcium, hydroxyproline, or DNA. There were nodescribed.(Endocrinology94: 915, 1974)