Transient Intolerance to Exogenous Fructose in the Newborn *

Open Access
Publisher Website
Google Scholar
Abstract
The rapid injection of one g/kg fructose intravenously to normal newborn infants resulted in a prompt transient depression of the concentration of glucose in the blood. This effect was greatest in infants under 6 hours of age, but occurred to some degree at all ages up to 13 days. The rate of fructose disappearance from the blood was under 1.77%/minute for infants less than 24 hours of age and increased with age to 3.17%/minute for the older infants. When fructose was administered to infants after a prior dose of epinephrine subcutaneously and glucagon intravenously, the rise in the concentration of glucose in the blood was immediately suppressed and a fall in concentration occurred. This indicated that fructose inhibited the release of glucose from the liver. Tolerance tests with galactose and fructose given successively substantiated this conclusion. The authors suggested that a maturation or adaptation of fructokinase or fructose aldolase, or both, occurs in the liver of the newborn infant in the initial hours after birth.