[Behavior of urinary magnesium in comparison with urinary calcium and oxaluria in rats subjected to portacaval anastomosis].

Rats with a portacaval anastomosis are known to be susceptible to develop uric acid stones. The present studies were undertaken to investigate urinary Mg, Ca and oxalate excretion in such rats. We found that their Mg excretion was doubled, Ca excretion tripled, and oxaluria somewhat decreased. The Ca crystallization attributed to the increased Ca2+ in the urine is, therefore, somewhat held in check by the increased presence of Mg in the urine and by decreased oxalates.