Center for Pediatric Nutrition Research, University of Utah, Salt Lake City, Utah 84108, USA.
Early Hum Dev. 2013 Jun;89(6):387-92. doi: 10.1016/j.earlhumdev.2012.12.005. Epub 2013 Jan 3.
Preterm infants are exposed to numerous stressors during hospitalization and by term corrected gestational age they have lower body weight but a greater proportion of total body as well as abdominal visceral adipose tissue (VAT) accumulation. Greater abdominal VAT stores have a known association with metabolic syndrome. Mechanical-tactile stimulation (MTS) improves modulation of stress response in both humans and rodents. We hypothesize that MTS, administered during an established model of neonatal stress, would decrease stress-driven adiposity and prevent associated metabolic imbalances in adult rats. Neonatal stress, administered to rat pups from postnatal days 5 to P9, consisted of needle puncture and hypoxic/hyperoxic challenge during 60 min of maternal separation (STRESS; n=20). Mechanical-tactile stimulation (MTS; n=20) was administered to rat pups for 10 min during maternal separation in the stress protocol. Control animals received standard care (CTL; n=20). MRI measured adult (P120) abdominal total fat mass, subcutaneous (SAT) and visceral adipose tissue (VAT). Body weight and fasting serum adiponectin, leptin, glucose, insulin, and corticosterone were also measured. STRESS results in elevated VAT/SAT ratio compared to CTL but lower abdominal total fat mass and abdominal SAT. STRESS males experience hyperinsulinemia. Both STRESS and MTS had elevated leptin with lower adiponectin and corticosterone compared to CTL. In summary, neonatal stress promotes greater abdominal VAT accumulation and, in males, caused hyperinsulinemia and hypoadiponectinemia. Importantly, MTS normalized the VAT/SAT ratio and prevented hyperinsulinemia. We speculate that MTS ameliorates some of the negative metabolic consequences of early life perturbations due to neonatal stress exposure.
早产儿在住院期间会接触到许多应激源，而到了校正胎龄足月时，他们的体重较低，但总体和腹部内脏脂肪组织（VAT）的比例却较高。腹部 VAT 储存量越大，与代谢综合征的相关性就越高。机械触觉刺激（MTS）可改善人类和啮齿动物应激反应的调节。我们假设，在已建立的新生儿应激模型中给予 MTS，将减少应激引起的肥胖，并预防成年大鼠相关的代谢失衡。对新生大鼠从出生后第 5 天到第 9 天进行新生儿应激处理，包括在 60 分钟的母婴分离期间进行针刺和低氧/高氧挑战（STRESS；n=20）。在应激方案中，对母婴分离期间的大鼠幼仔进行 10 分钟的机械触觉刺激（MTS；n=20）。对照组动物接受标准护理（CTL；n=20）。MRI 测量成年（P120）腹部总脂肪量、皮下（SAT）和内脏脂肪组织（VAT）。还测量了体重和空腹血清脂联素、瘦素、葡萄糖、胰岛素和皮质酮。与 CTL 相比，STRESS 导致 VAT/SAT 比值升高，但腹部总脂肪量和腹部 SAT 较低。STRESS 雄性出现高胰岛素血症。与 CTL 相比，STRESS 和 MTS 均使瘦素升高，脂联素和皮质酮降低。总之，新生儿应激会导致腹部 VAT 积聚增加，并且在雄性中引起高胰岛素血症和低脂联素血症。重要的是，MTS 使 VAT/SAT 比值正常化，并预防高胰岛素血症。我们推测，MTS 改善了由于新生儿应激暴露而导致的生命早期波动的一些负面代谢后果。
