1. Because of the clinical observation that the capacity to form new plasma proteins is sometimes impaired in cases of nephritis (2), experiments were performed to determine whether the impaired function in the nephritic is related to nitrogen retention.
2. These experiments consisted of producing renal injury by injecting uranium nitrate into standard hypoproteinemic dogs and comparing the rate of blood plasma protein formation under these conditions of nitrogen retention with that in the uninjured dog.
3. Despite elevations in blood N.P.N. to more than ten times normal, no interference with plasma protein formation was observed. These elevations in N.P.N. affected principally the urea and undetermined fractions.
4. Neither elevation in N.P.N. nor proteinuria per se appears to have any effect upon plasma protein production. Possibly the deficient production of plasma proteins in the nephritic is related to a more general disturbance in metabolism in which the elevation in N.P.N. is secondary.