Sulphate excretion by dogs following ingestion of ammonium sulphate or meat.

1. When normal conscious dogs were given small doses of (NH4)2SO4 by stomach tube, the rate of excretion of SO4 increased due to increase in plasma SO4 without change in creatinine clearance. After eating meat, increased SO4 excretion was due to increase in glomerular filtration rate without change in plasma SO4. 2. The calculated rate of tubular reabsorption of SO4 did not change significantly either after (NH4)2SO4 or after meat. 3. The rate of production of SO4 after meat was estimated. In 4 hr approximately one fifth of the S in meat was converted to inorganic SO4; in the same time approximately one third of the N in the meat was converted into urea. 4. Half of the SO4 in the doses of (NH4)2SO4 was absorbed from the gut; all of the NH was converted into urea. (NH4)2SO4 thus produced acidosis. 5. After (NH4)2SO4, increased excretion of NH4+ accompanied the increased excretion of SO4-but Na+, K+ in urine also increased.