Nationwide Children’s Hospital, The Ohio State University College of Medicine, USA.
Am J Physiol Gastrointest Liver Physiol. 2010 Dec;299(6):G1386-95. doi: 10.1152/ajpgi.00289.2010. Epub 2010 Sep 23.
We defined the sensory-motor characteristics of the lower esophageal sphincter relaxation (LESR) (stimulus threshold volume, response onset, and relaxation period, relaxation magnitude, nadir) during maturation in human neonates. We hypothesized that LESR kinetics differs during maturation and with peristaltic reflex type. Basal and adaptive esophageal motility testing was performed (N = 20 premature neonates) at 34.7 and 39.1 wk (time 1 and time 2). Effects of midesophageal provocation with graded stimuli (N = 1,267 stimuli, air and liquids) on LESR kinetics during esophagodeglutition response (EDR) and secondary peristalsis (SP) were analyzed by mixed models. Frequency of LESR with basal primary peristalsis were different during maturation (P = 0.03). During adaptive responses with maturation, 1) the frequencies of peristaltic reflexes and LESR were similar; 2) liquid stimuli resulted in a shorter LESR response latency and LESR nadir and greater LESR magnitude (all P < 0.05); 3) media differences were noted with LESR response latency (air vs. liquids, P < 0.02); and 4) infusion flow rate-LESR were different (P < 0.01 for air and liquids). Mechanistically, 1) frequency of LESR was greater during peristaltic reflexes at both times (vs. none, P < 0.0001); 2) LESR response latency, duration, and time to complete LESR were longer with EDR (all P < 0.05, vs. SP at time 2); and 3) graded stimulus volume LESR were different for air and liquids (P < 0.01). In conclusion, sensory-motor characteristics of LESR depend on the mechanosensitive properties of the stimulus (media, volume, flow), type of peristaltic reflex, and postnatal maturation. Maturation modulates an increased recruitment of inhibitory pathways that favor LESR.
我们定义了人类新生儿食管下括约肌松弛（LES）的感觉运动特征（刺激阈值容积、反应起始和松弛期、松弛幅度、最低点）在成熟过程中的变化。我们假设 LES 动力学在成熟过程中以及与蠕动反射类型不同。在 34.7 和 39.1 周（时间 1 和时间 2）时，对基础和适应性食管运动进行了测试（N=20 例早产儿）。通过混合模型分析食管吞咽反应（EDR）和继发性蠕动（SP）期间中食管刺激对 LES 动力学的影响（N=1267 次刺激，空气和液体）。在成熟过程中，基础原发性蠕动时 LES 松弛的频率不同（P=0.03）。在成熟时的适应性反应中，1）蠕动反射和 LES 的频率相似；2）液体刺激导致 LES 反应潜伏期和 LES 最低点缩短，LES 幅度增大（均 P<0.05）；3）注意到 LES 反应潜伏期的介质差异（空气与液体，P<0.02）；4）输注流速与 LES 的关系不同（空气和液体时 P<0.01）。从机制上讲，1）在两次时间的蠕动反射中，LES 的频率更高（与无反射相比，P<0.0001）；2）EDR 时 LES 反应潜伏期、持续时间和完成 LES 的时间更长（与 SP 相比，均 P<0.05，在时间 2 时）；3）空气和液体的 LES 反应对不同大小的刺激体积有不同的反应（P<0.01）。总之，LES 的感觉运动特征取决于刺激的机械敏感特性（介质、体积、流速）、蠕动反射类型和产后成熟度。成熟调节了抑制性通路的增加募集，有利于 LES 的松弛。
