In infants studied in the first month of life there was a gradual development of the ability to excrete excess water in a short period of time. When a water load was given according to body weight, orally or intravenously, no diuresis was observed in infants under 3 days of age. In comparison, all individuals tested over 3 days of age responded with a definite increase in water excretion. As early as 2 weeks of age and in all infants over one month of age the entire water load of 3 to 5% of their body weight was excreted in a three hour period following the administration of fluid. No difference in the diuretic response to a water load was apparent in full term and premature infants of comparable postpartum age.
Antidiuretic hormone whether produced endogenously following thirst, excitation or pain, or injected in the form of exogenous antidiuretic principle, caused a decrease in urine output only in infants who received a water load and who were responding to it with a diuresis.
When diuresis followed a water load, the degree of the renal response to antidiuretic hormone could not be compared in the various age groups studied, because of the inability to control a sudden release of endogenous hormone provoked by excitatory stimuli.
The hormone was detectable in the urines of infants under 3 days of age after fluid deprivation; this is assumed to be evidence of a functioning neurohypophysis.
- Received December 5, 1952.
- Copyright © 1953 by the American Academy of Pediatrics