Hypophosphatemia induced by dietary aluminium hydroxide supplementation in growing pigs: effects on erythrocytes, myocardium, skeletal muscle and liver.

Three groups of pigs were studied during and after 10 weeks of treatment with either Al(OH)3 (Al[OH]3-group, n = 8) to induce hypophosphatemia. AlPO4 (AlPO4-group, n = 8, aluminium control without hypophosphatemia) or no addition to the feed (control group, n = 8). Blood samples were taken at the start of the experiment and after 3, 6 and 10 weeks and were analyzed for phosphate, calcium and 2,3-diphosphoglycerate (2,3-DPG). Samples from myocardium, skeletal muscle and liver were obtained in connection with exsanguination and analyzed for glycogen, adenosine-tri-phosphate (ATP), creatine phosphate (CP), glucose-6-phosphate (G-6-P) and lactate. The Al(OH)3-group became hypophosphatemic and hypercalcemic with low levels of 2,3-DPG in erythrocytes within 3 weeks and showed a retarded growth rate. After 10 weeks the Al(OH)3-group had low levels of ATP in myocardium as compared with the control-group and low levels of G-6-P as compared with the AlPO4-group. No disturbances on electro-cardiograms registered at rest could be documented. G-6-P concentration was low in the biceps muscle in the Al(OH)3-group as compared with the AlPO4-group and in the liver low G-6-P concentration was seen in addition to high lactate concentration. The fibre type composition in M. Longissimus did not differ between groups, but the Al(OH)3-group had, due to retardation in growth, smaller mean fibre-areas than pigs in the AlPO4-group.(ABSTRACT TRUNCATED AT 250 WORDS)