Sugar absorption by foetal and neonatal rat intestine in vitro.

Abstract

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.

Developmental Maturation of <i>D</i>-Glucose Active Transport System in Rat Intestine

“…Regardless of the mechanism(s) responsible for the changes in the Vmax and K, of the D-glucose transport sys tem, it seems that the intestine of the youn ger rats has developed an efficient mecha nism to transport an important fuel supply to meet the needs of the rapidly growing young animal. The present study comple ments and extends previous observations [7,8,11] and allows better longitudinal charac terization of the kinetic parameters of the active transport of D-glucose at various stages of maturation including the develop ment aspects of the suckling period.…”

“…Developmental maturation of the intesti nal transport system of ¿>-glucose was the subject of a few reports [7,8,11 ]. However, a detailed longitudinal study on the ontogene sis of the ¿¿-glucose-active transport system from early life to adulthood is lacking.…”

“…Therefore, a 12-min incubation was chosen as the stan dard incubation time in all subsequent ex periments, since transport during this time generally measures the unidirectional flux across the mucosal surface and remains unaffected by tissue metabolism of the sub strate. Figure 2 shows the results of the trans port of D-glucose by the active mechanism as a function of concentration (0.1-30 mM) in rats of different age groups (3,5,7,9,11,17,25 and 90 days old). Kinetic parameters (Vmax and K,) of the active transport system of D-glucose were calcu lated using the Lineweaver-Burk plot ( fig.…”

“…Developmental changes in the D-glucose-active transport system were examined in jejunum of rats of different age groups (3,5,7,11,13,17, 25 and 90 days old) using the intestinal sheet technique. Transport of D-glucose by the active system was determined by subtracting the passive component, as determined by uptake of L-3H-glucose from the total uptake.…”

Effect of epidermal growth factor on small intestinal sodium/glucose cotransporter–1 expression in a rabbit model of intrauterine growth retardation

“…border membrane nutrient carriers develop during the first trimester in the human, with regional specificity becoming apparent during fetal life with maximal transport rates seen in the jejunum in both human and animal models [1,2]. Studies of active nutrient transport parallel this pattern of native development in the fetal rabbit [3].…”