SILICON AND ALUMINUM AND THEIR INTERRELATIONSHIP IN SERUM AND URINE AFTER RENAL-TRANSPLANTATION

The present study was undertaken to establish the relationship between serum and urine silicon and improve renal function and examine whethe r the increased urinary excretion of aluminium observed after successf ul renal transplantation was associated with silicon. The changes in s ilicon and aluminium concentrations in serum and urine were measured i n 15 patients for a period of up to 17 days following a first renal tr ansplant. Serum silicon, unlike aluminium, progressively decreased wit h improving renal function and was significantly positively correlated with serum aluminium but not with the silicon excretion. The urine ex cretion of aluminium peaked between 4-8 days post-transplantation and was highly significantly positively correlated with urine silicon. The individual patient fractional excretion profiles of aluminium and sil icon were variable but in general gave significant positive correlatio ns suggesting that the elements may be cleared by the kidney through a common mechanism or as a chemical species, possibly an hydroxyalumino silicate. If soluble silicon can chemically interact with aluminium in vivo it may, as in the biosphere, be important in the control of alum inium toxicity and eventual detoxification. Thus, elevated serum silic on concentrations may help to alleviate aluminium toxicity in end-stag e renal disease and assist in the rapid clearance of aluminium seen af ter kidney transplantation.