This paper is concerned with the changes found in the kidneys of three groups of rabbits that had been fed high protein diets for periods as long as twenty-four months. Many of the animals developed an increased blood pressure and clinical evidence of kidney injury.1 This evidence consisted first of albumin and casts in the urine, later of an increase of the nonprotein nitrogen and urea nitrogen of the blood and finally of a decrease of carbon dioxide of the blood plasma.
The routine procedure in experiments were as follows:
Forty-eight carefully selected young rabbits were placed in individual metabolism cages. None of these animals had a spontaneous nephritis or a systolic blood pressure higher than 74 of mercury. The cages were kept out doors the year around. The blood pressures were obtained once each month by a method previously described.2 At monthly intervals also, twenty-four hour samples of the