EFFECT OF SMALL VARIATIONS OF ALUMINUM INTAKE ON CALCIUM-METABOLISM IN YOUNG-RATS

Background: While in the adult Al intoxication requires high dosages, little is known on the threshold level of Al toxicity in the young. Me thods: Weaning rats were fed for 90 days ore of four diets differing b y their content in Ca (7.5 vs <0.5g/<g diet)(Ca+/-) and Al (10.6 vs 8. 4 mg/kg)(Al+/-); Al supplementation was 30% above the standard level o f diet. Ca and Al levels were measured in liver, bone (femur), and bra in. Results: Ca-had a significant negative effect on growth which was further reduced by Al+; in Ca sufficient/Al+ animals, Al concentration s were significantly increased in bone and brain and tended to increas e in liver; Ca decreases observed in these three organs were only sign ificant in brain. Ca deficiency further enhanced the Al deposit in bon e at both levels of Al intakes, and reduced Ca concentrations in these three organs in Al+ animals; in Ca-/Al- animals, the decrease in Ca d isplayed in the three tissues reached a significant level in brain. Co nclusions: This study suggests that in the growing subject the side ef fects of small variations of Al intake can be enhanced when they are c ombined with other mineral imbalances. (C) 1997 Lippincott-Raven Publi shers.