GENDER, DIETARY COPPER AND CARBOHYDRATE SOURCE INFLUENCE CARDIAC COLLAGEN AND LYSYL OXIDASE IN WEANLING RATS

The present investigation was conducted to determine the effects of co nsumption of diets containing fructose or cornstarch on cardiac collag en metabolism in weanling male and female rats fed copper-deficient or copper-adequate diets for 5 wk. Although both male and female rats th at consumed the copper-deficient diet containing fructose were similar ly copper deficient, only the males showed severe cardiac pathologies and two died prematurely due to heart-related abnormalities. These pat hologies were accompanied by a significant reduction of cardiac lysyl oxidase activity and elevated soluble and total cardiac collagen conce ntrations compared with rats fed copper-adequate diets. These abnormal ities were less severe in copper-deficient rats fed cornstarch. The da ta show that the activity of the copper-containing enzyme lysyl oxidas e is affected by both dietary carbohydrate and gender. The pathologies of heart tissue could be the result of abnormal crosslinking of colla gen induced by the combination of copper deficiency, fructose feeding and the sex of the rats.