Haley S, O'Grady S, Gulliver K, Bowman B, Baldassarre R, Miller S, Lane R H, Moyer-Mileur L J
Center for Pediatric Nutrition Research, University of Utah, Salt Lake City, Utah.
J Musculoskelet Neuronal Interact. 2011 Sep;11(3):234-42.
Neonatal stress impairs postnatal bone mineralization. Evidence suggests that mechanical tactile stimulation (MTS) in early life decreases stress hormones and improves bone mineralization. Insulin-like growth factor (IGF1) is impacted by stress and essential to bone development. We hypothesized that MTS administered during neonatal stress would improve bone phenotype in later life. We also predicted an increase in bone specific mRNA expression of IGF1 related pathways.
Neonatal stress (STRESS) and MTS (STRESS+10 min of MTS) were given from D6 to D10 of rat life and tissue was harvested on D60 of life. Dual energy x-ray absorptiometry (DXA), bone morphometry, serum osteocalcin, type I procollagen N-terminal propeptide (PINP), tartrate-resistant acid phosphatase (TRAP), and bone and liver mRNA levels of IGF1, IGF1 receptor (IGF1R), and growth hormone receptor (GHR) were measured.
Stress resulted in reduced bone area and bone mineral content (BMC) compared to naive control (CTL). MTS intervention increased BMC and tibial growth plate width compared to STRESS. MTS also resulted in higher osteocalcin, and, in males, lower TRAP (p<0.05). MTS resulted in three-fold, two-fold, and six-fold higher bone specific IGF1, IGF1R, and GHR, respectively (p ≤ 0.001) compared to STRESS.
MTS in early postnatal life improves long-term bone mineralization. IGF1 and related pathways may explain improved BMC.
新生儿应激会损害出生后的骨矿化。有证据表明，生命早期的机械触觉刺激（MTS）可降低应激激素水平并改善骨矿化。胰岛素样生长因子（IGF1）受应激影响，对骨骼发育至关重要。我们假设在新生儿应激期间给予MTS可改善后期生活中的骨表型。我们还预测与IGF1相关途径的骨特异性mRNA表达会增加。
在大鼠出生后第6天至第10天给予新生儿应激（应激组）和MTS（应激+10分钟MTS组），并在出生后第60天采集组织。测量双能X线吸收法（DXA）、骨形态计量学、血清骨钙素、I型前胶原N端前肽（PINP）、抗酒石酸酸性磷酸酶（TRAP）以及IGF1、IGF1受体（IGF1R）和生长激素受体（GHR）的骨和肝脏mRNA水平。
与未处理的对照组（CTL）相比，应激导致骨面积和骨矿物质含量（BMC）降低。与应激组相比，MTS干预增加了BMC和胫骨生长板宽度。MTS还使骨钙素水平升高，在雄性中，TRAP水平降低（p<0.05）。与应激组相比，MTS使骨特异性IGF1、IGF1R和GHR分别升高了三倍、两倍和六倍（p≤0.001）。
出生后早期的MTS可改善长期骨矿化。IGF1及相关途径可能解释了BMC的改善。
