Effects of niceritrol on faecal and urinary phosphate excretion in normal rats

Background. Phosphate binders such as aluminium hydroxide and calcium carbo nate have several side-effects so that they are not ideal for clinical use. Recently we reported that administration of niceritrol at 750 mg/day to pa tients with HDL hypocholesterolaemia undergoing dialysis decreased the seru m phosphate concentration. To clarify the mechanism of reduction of the ser um phosphate concentration by niceritrol in patients undergoing dialysis, t he effects of niceritrol on faecal and urinary phosphate excretion were exa mined in normal rats. Methods, Niceritrol suspension in 5% gum arabic was administered for 4 days in normal rats. Faeces and urine were collected in metabolic cage and anal ysed for phosphate content. Results and conclusions, Faecal phosphate excretion significantly increased in the groups with administration of 100 and 500 mg/kg niceritrol, but not in the group with 20mg/kg. On the other hand, urinary phosphate excretion was not significantly changed in the groups on 20-500 mg/kg. Retention of p hosphate was significantly suppressed in the groups on 100 and 500 mg/kg. A increased faecal phosphate excretion by niceritrol is presumably the mecha nism by which serum phosphate concentration is reduced in dialysis patients .