Translational Medicine Program, Hospital for Sick Children Research Institute; Department of Paediatrics and Physiology, University of Toronto, Toronto, Ontario, Canada.
Pediatr Res. 2018 Nov;84(5):751-756. doi: 10.1038/s41390-018-0154-1. Epub 2018 Aug 24.
When compared with infant formula, human milk enhances gastric emptying in preterm infants. Hydrogen peroxide (HO) is present in large quantities in human milk that has an antimicrobial role for the mother and infant. In vitro adult rat studies suggest that HO facilitates gastric motor contraction. Hypothesizing that HO enhances gastric motility, we investigated its effects on the newborn rat stomach tissue.
Rat newborn and adult gastric fundic segments, or their smooth muscle cells, were used to evaluate the muscle response to HO exposure. Tissue expression of Rho kinase 2 (ROCK-2; Western blot), its catalase activity, and HO content (Amplex Red) were measured. HO gastric mucosal diffusion was evaluated with Ussing chambers.
In both newborn and adult rats, HO induced gastric muscle contraction and this response was attenuated by pre-incubation with the antioxidant melatonin. HO passively diffused across the gastric mucosa. Its effect on the muscle was modulated via ROCK-2 activation and inhibited by melatonin.
HO, at a concentration similar to that of human milk, promotes gastric motility in the rat. To the extent that the present findings can be clinically extrapolated, the human milk HO content may enhance gastric emptying in neonates.
与婴儿配方奶粉相比，母乳可促进早产儿的胃排空。母乳中含有大量的过氧化氢（HO），对母婴均具有抗菌作用。体外成年大鼠研究表明，HO 有助于胃动力收缩。我们假设 HO 可增强胃动力，因此研究了其对新生大鼠胃组织的影响。
使用新生和成年大鼠胃底段组织或其平滑肌细胞来评估 HO 暴露对肌肉的影响。通过 Western blot 检测 Rho 激酶 2（ROCK-2）的组织表达、其过氧化氢酶活性和 HO 含量（Amplex Red）。使用 Ussing 室评估 HO 胃黏膜扩散。
在新生和成年大鼠中，HO 均可诱导胃肌肉收缩，而抗氧化剂褪黑素的预孵育可减弱这种反应。HO 可被动扩散穿过胃黏膜。其对肌肉的作用通过 ROCK-2 激活进行调节，并被褪黑素抑制。
与母乳中浓度相似的 HO 可促进大鼠的胃动力。在某种程度上，可以将目前的发现从临床推断出来，人乳中的 HO 含量可能会增强新生儿的胃排空。
