BACKGROUND & AIMS:
:Intestinal amino acid (AA) transport is critical for the supply of AA to other tissues. Few studies regarding AA intestinal transport systems during the period from postnatal intense development of piglets until weaning are available. In the present study, we measured the intestinal expression of b(0,+)AT according to developmental stage using the suckling Huanjiang piglet model, and documented the effect of intra-uterine growth restriction (IUGR) on such expression using real-time PCR and Western blot analysis. Suckling piglets that recovered after IUGR and those with normal body weights (NBW) were used after birth or at 7, 14 and 21 d of age. Blood samples were used for the measurement of plasma AA concentrations, and the jejunum was collected for the measurement of b(0,+)AT expression. In NBW piglets, b(0,+)AT expression was markedly decreased from days 0 to 21 (P< 0.01) and remained at a low level during all the suckling periods. In IUGR piglets, there was a marked decrease in b(0,+)AT expression at birth, which remained lower, when compared with NBW piglets, during the suckling period. These results coincided with decreased plasma arginine concentration at birth and decreased lysine concentration in 21-d-old piglets (P< 0.05). It is concluded that the high expression of b(0,+)AT at birth decreases during the suckling period, and that IUGR is associated with decreased expression of this apical AA transporter. The possible causal relationship between decreased b(0,+)AT expression and lower body weight of IUGR piglets in the suckling period is discussed.
背景与目标:
: 肠道氨基酸 (AA) 运输对于向其他组织供应AA至关重要。从仔猪出生后到断奶期间,关于AA肠道运输系统的研究很少。在本研究中,我们使用哺乳环江仔猪模型根据发育阶段测量了b(0,) 的肠道表达,并使用real-time PCR和Western blot记录了子宫内生长限制 (IUGR) 对这种表达的影响。IUGR后恢复的哺乳仔猪和体重正常 (NBW) 的仔猪在出生后或7、14和21 d时使用。血液样本用于测量血浆AA浓度,并收集空肠用于测量b(0,) AT表达。在NBW仔猪中,b(0,+)AT表达从第0天到第21天明显降低 (P< 0.01),并在所有哺乳期间保持在低水平。在IUGR仔猪中,出生时表达的b(0,) 显着降低,与NBW仔猪相比,在哺乳期间仍然较低。这些结果与21 d仔猪出生时血浆精氨酸浓度降低和赖氨酸浓度降低相吻合 (P< 0.05)。结论是,在哺乳期间,出生时b(0,) 的高表达降低,并且IUGR与这种顶端AA转运蛋白的表达降低有关。讨论了乳期IUGR仔猪b(0,+)AT表达降低与体重降低之间的可能因果关系。