Renal ammonia and acid excretion in infant rats.

GOLDSTEIN, LEON. Renal ammonia and acid excretion in infant rats. Am. J Physiol. 218(5) : 1394-l 398. 1970.-The rate of ammonia excretion in infant rats (9-14 days old) was approximately two-thirds the adult level. Excretion of titratable acid (TA) was approximately one-third that of adult rats until 14 days after birth. Between 14 and 21 days after birth, the rates of excretion of ammonia and TA increased to levels exceeding those of adult rats. The response of ammonia excretion to administration of an acid load (NH&l) was significantly lower in infant rats than in adults. The ability to respond in a manner quantitatively similar to adults developed between 14 and 21 days after birth. The percent increase in ammonia excretion after repeated (2-3 days) administration of NH&l was similar (500-6007,) in infant and adult rats. The absolute increase in ammonia excretion in infants was two-thirds that of adults. Deoxycorticosterone acetate administration had no effect on the response of the infant kidney to an acid load.