A POSSIBLE NON-ALUMINUM ORAL PHOSPHATE BINDER - A COMPARATIVE-STUDY ON DIETARY PHOSPHORUS ABSORPTION

The aim of this study was to highlight a possible new non-aluminum pho sphate-binder to limit hyperphosphatemia in patients with renal failur e. Lanthanum chloride hydrate was evaluated as a dietary phosphate bin der in rats. Aluminum chloride hexahydrate was evaluated as a referenc e. Animals were divided in five groups (6 animals per group): 1 contro l group (C), 2 aluminum groups (Al-1 and Al-2), receiving different do ses of aluminum chloride hexahydrate and 2 lanthanum groups (La-1 and La-2), receiving different doses of lanthanum chloride hydrate. During the treatment, urine and stools were collected. At the end of the tre atment animals were sacrificed and plasma and different organs were co llected (liver, spleen, kidneys, brain and femur). To highlight the po ssible transfer of lanthanum in rat tissues, a long-term (100 days) st udy was carried with a high dose. At the end of the treatment, lanthan um determinations were carried out on several tissues (liver, spleen, kidneys, brain, femur and lungs). Determinations of phosphorus and cal cium levels in plasma indicated that lanthanum chloride hydrate showed as good results as aluminum chloride hexahydrate. Lanthanum chloride hydrate significantly (p < 0.01) reduced the bone phosphorus burden. D ecreases of urinary excretion and increases in fecal excretion of phos phorus indicated a severe phosphorus depletion in all treatments (Al a nd La). Unfortunately, in the long-term study, lanthanum traces could only be determined in the different tissues but not in plasma. However , in comparison with the equivalent aluminum treatment, the transfer o f lanthanum was less important than aluminum transfer. Consequently, l anthanum could provide a possible alternative to aluminum.