Sugar absorption by foetal and neonatal rat intestine in vitro.

1. Sugar absorption by foetal and neonatal rat intestine has been examined using an in vitro accumulation technique. 2. The capacity for active sugar absorption is present in the rat intestine by the 17th day of gestation. Considerable variation in uptake occurs during the first month post partum; the greatest uptake place during the first week. 3. The absorption of sugars by the developing gut resembles in several respects that by the mature intestine. However, the adult pattern of functional localization along the intestine is not fully established until after the 3rd week post partum. 4. Kinetic studies indicate that variations with age in the distribution of sugar "carriers' along the intestine, rather than changes in the "carriers' themselves, account for the observed variations in absorption.