The effect of tungstate ingestion on xanthine oxidase in milk and liver

Abstract

1. The ingestion of doses of up to 6 g sodium tungstate (56 mg W/kg body-weight) by goats was found to diminish the amount of xanthine oxidase secreted in their milk so that, in some samples, the enzyme became undetectable. This effect occurred whether the goats were eating a semi-synthetic or a conventional diet.2. Tungstate ingestion by goats did not affect the concentration of riboflavine in their milk.3. The ingestion of sodium tungstate by young goats for 3–5 months diminished the amount of xanthine oxidase in their livers.4. When given in early lactation to two cows, doses of sodium tungstate (up to 20 g) diminished the titre of xanthine oxidase in their milk with no concomitant effect on the yields.5. Much later in lactation the milk phosphatase of these two cows was poorly correlated with milk xanthine oxidase. Reasons for this are discussed.6. Under anaerobic conditions, with xanthine as substrate and triphenyl-tetrazolium chloride as hydrogen acceptor, neither molybdate nor tungstate affected the xanthine oxidase activity of cow's or goat's milk in vitro. Molybdate in vitro did not enhance the very low titre of human milk.