Effect of L-alanyl-L-glutamine on expression of insulin-like growth factor-1 in intestinal tissues of low-birth-weight newborn rats with hypoxia/reoxygenation-induced intestinal injury
XU Fen1, ZHU Chuan-Rui1, ZHAN Yuan-Li1, LU Guang-Jin1, SU Hao-Bin2
Department of Neonatology, Shenzhen Bao'an District Maternal and Child Health Care Hospital, Shenzhen, Guangdong 518133, China
Abstract Objective To study the effect of L-alanyl-L-glutamine (Ala-Gln) on the levels of insulin-like growth factor-1 (IGF-1) and IGF-1 receptor (IGF-1R) in the intestinal tissues of low-birth-weight (LBW) newborn rats with hypoxia/reoxygenation-induced intestinal injury. Methods Pregnant rats were fed with or without smoking. The rats born by those fed without smoking were included in group A; for the rats born by those fed with smoking, normal-birth-weight rats were included in group B, and LBW rats were randomly divided into control group (group C), hypoxia/reoxygenation (H/R) group (group D), and Ala-Gln group (group E). Each group consisted of 24 newborn rats. The rats in groups D and E received H/R treatment twice a day for three consecutive days to establish an intestinal injury model; the rats in group E were intraperitoneally injected with Ala-Gln (10 ml/kg) before daily H/R treatment, while those in groups C and D were given an equal dose of normal saline by intraperitoneal injections. On days 4, 7, and 10 after birth, 8 rats were sacrificed in each group to collect intestinal tissues. The IGF-1 levels in intestinal tissues were measured using ELISA, and IGF-1R levels were measured by immunohistochemistry. Results There were no significant differences in IGF-1 and IGF-1R levels between groups A and B at all time points. The levels of IGF-1 and IGF-1R in group C kept increasing, were higher than those in other groups on day 7 (P<0.05), and reached a normal level on day 10, without significant differences compared with those in groups A and B. Group D had significantly lower IGF-1 and IGF-1R levels than group C at all time points (P<0.05). The levels of IGF-1 and IGF-1R in group E were lower than those in group C on days 4 and 7 (P<0.05), but they increased to approximately the levels in group C and were significantly higher than those in group D on day 10. Conclusions Intrauterine and postnatal hypoxia may induce intestinal injury in LBW newborn rats, and parenteral administration of high-dose Ala-Gln can reduce hypoxia-induced intestinal injury. Therefore, Ala-Gln has a protective effect against hypoxia-induced intestinal injury.
About author:: 10.7499/j.issn.1008-8830.2015.05.018
Cite this article:
XU Fen,ZHU Chuan-Rui,ZHAN Yuan-Li et al. Effect of L-alanyl-L-glutamine on expression of insulin-like growth factor-1 in intestinal tissues of low-birth-weight newborn rats with hypoxia/reoxygenation-induced intestinal injury[J]. CJCP, 2015, 17(5): 502-507.
XU Fen,ZHU Chuan-Rui,ZHAN Yuan-Li et al. Effect of L-alanyl-L-glutamine on expression of insulin-like growth factor-1 in intestinal tissues of low-birth-weight newborn rats with hypoxia/reoxygenation-induced intestinal injury[J]. CJCP, 2015, 17(5): 502-507.
Xu CL, Sun R, Qiao XJ, et al. Protective effect of glutamine on intestinal injury and bacterial community in rats exposed to hypobaric hypoxia environment[J]. World J Gastroenterol, 2014, 20(16): 4662-4674.
[3]
Zhao D, Bakirtzi K, Zhan Y, et al. Insulin-like growth factor-1 receptor transactivation modulates the inflammatory and proliferative responses of neurotensin in human colonic epithelial cells[J]. J Biol Chem, 2011, 286(8): 6092-6099.
[4]
Meyer KF, Martins JL, Freitas Filho LG, et al. Evaluation of an experimental model of necrotizing enterocolitis in rats[J]. Acta Cir Bras, 2006, 21(2): 113-118.
Lagiou P, Samoli E, Hsieh CC, et al. Maternal and cord blood hormones in relation to birth size[J]. Eur J Epidemiol, 2014, 29(5): 343-351.
[9]
Shul'ga AS, Butenko EV, Aleksandrova AA, et al. The evaluation of changes in concentration of ghrelin, somatotropin, insulin-like growth factor-1, insulin, leptin and thyroid hormones in mother and umbilical blood in case of physiologic pregnancy with normosomia and macrosomia of fetus[J]. Klin Lab Diagn, 2013, 58(2): 16-18.
[10]
Zhou W, Li W, Zheng XH, et al. Glutamine downregulates TLR-2 and TLR-4 expression and protects intestinal tract in preterm neonatal rats with necrotizing enterocolitis[J]. J Pediatr Surg, 2014, 49(7): 1057-1063.
[11]
Pawlik D, Lauterbach R, Hurkała J, et al. The effects of enteral administration of glutamine enriched solution in very low birth weight infants on reducing the symptoms of feeding intolerance. A prospective, randomized pilot study[J]. Med Wieku Rozwoj, 2012, 16(3): 205-211.