Influence of succinylsulfathiazole and folic acid on glutamic acid excretion.

At weaning or shortly thereafter, eighteen male, albino rats from six litters (Osborne and Mendel strain; average weight 39 gm.) were placed on purified diets as follows: one rat in each litter was given the unsupplemented basal diet, one was given the basal diet supplemented with SS (1 per cent succinylsulfathiazole replacing an equal amount of glucose), and one was given the basal diet supplemented with SS plus FA (4 y of FA1 per gm. of diet). The three animals in each litter were pair-fed to rule out effects due to differences in food intake. The basal diet supplemented with SS was the same as that used by Daft and Sebrell (1) except that the daily supplement included 20 y of vitamin K (2-methyl-1,4naphthoquinone, “menadione”) and 0.5 y of biotin. Blood counts (leucocyte, granulocyte, and hematocrit) were taken periodically, and, when the leucocyte count of the rats on the basal diet plus SS fell to 4000 per c.mm. or below and the granulocyte count to 200 or below, the rats were treated by adding 20 y of FA per gm. of diet. At this time, litter mate controls (receiving the basal diet or the basal diet supplemented with FA and SS), in each case, had higher granulocyte counts. The food intake of all six litters averaged approximately 8 gm. per day, except for the 3 or 4 days prior to treatment or death, when it fell to approximately 5 gm. per day. The food intake of the treated rats and their litter mates was restricted to the average intake prior to treatment. The average weight at the onset of granulocytopenia was 101 gm. Each rat was kept separately in a metabolism cage. The urine was