Oxidative damage and exocrine dysfunction of ovine fetal pancreas are induced by maternal nutritional restriction

ABSTRACT This study investigated oxidative damage and exocrine dysfunction of fetal pancreas caused by maternal nutritional restriction. Eighteen ewes carrying singleton fetus were randomly divided into control group (CG, ad libitum, 0.67 MJ ME/BW0.75/d, n = 6), restricted group 1 (RG1, 0.33 MJ ME/BW0.75/d, n = 6), and restricted group 2 (RG2, 0.18 MJ ME/BW0.75/d, n = 6) at d 90 of pregnancy. Maternal undernutrition was imposed from d 90 to 140 of pregnancy. At 140 d of gestation, fetal blood and pancreas tissue were collected to determine fetal pancreatic extracellular matrix, antioxidant capacity, and indicators of exocrine dysfunction. With the decrease of maternal nutrition, the fetal body weight, pancreatic weight, and DNA content were reduced in RG2 compared with CG, and increased and thickened collagen fibers were observed in RG2. Fetuses in RG2 exhibited increased collagen 3 (COL3) and fibronectin (FN) levels relative to CG, and the COL1:COL3 ratio was lower than that of the CG. For RG1, we found increased COL3 compared with CG. Malondialdehyde, serum amylase, and serum lipase in fetal pancreas in RG2 increased, but the total antioxidant capacity (T-AOC) decreased compared with the CG. The impaired ovine fetal pancreas growth, antioxidant imbalance, and pancreatic exocrine dysfunction are induced by maternal undernutrition during late pregnancy.

摘要 本研究针对母体营养限制所致胎羊胰腺氧化损伤与外分泌功能障碍展开探讨。将18只妊娠单胎胎儿的母羊于妊娠第90天随机分为3组：对照组（CG，自由采食（ad libitum），0.67 MJ ME/BW^0.75/天，n=6）、限制组1（RG1，0.33 MJ ME/BW^0.75/天，n=6）及限制组2（RG2，0.18 MJ ME/BW^0.75/天，n=6）。母体限饲周期为妊娠第90天至第140天。于妊娠第140天采集胎羊血液与胰腺组织，检测胎儿胰腺细胞外基质（extracellular matrix）、抗氧化能力及外分泌功能相关指标。结果显示，随着母体营养摄入水平降低，RG2组胎羊的体重、胰腺重量及DNA含量均较对照组降低，且该组可见胶原纤维增生增厚。RG2组胎羊的III型胶原（COL3）与纤连蛋白（FN）水平较对照组升高，I型胶原与III型胶原比值（COL1:COL3）低于对照组。RG1组胎羊的COL3水平亦较对照组升高。RG2组胎羊胰腺中的丙二醛、血清淀粉酶及血清脂肪酶水平升高，而总抗氧化能力（T-AOC）较对照组降低。综上，妊娠晚期母体营养不良可诱导胎羊胰腺生长受损、抗氧化失衡及胰腺外分泌功能障碍。