Expression profiles of brain-derived neurotrophic factor in the spinal dorsal horn of young rats with visceral hypersensitivity / 中国当代儿科杂志

ABSTRACT

<p><b>OBJECTIVE</b>To explore the relationship between the expression of brain-derived neurotrophic factor (BDNF) in the spinal dorsal horn and the increase in visceral hypersensitivity in young rats by establishing a young rat model of visceral hypersensitivity by neonatal maternal separation (NMS).</p><p><b>METHODS</b>Thirty-two newborn Sprague-Dawley rats were randomly and equally divided into four groups by a 2×2 factorial design: control, NMS, colorectal distension (CRD), and NMS+CRD. The newborn rats in the NMS and NMS+CRD groups were subjected to 3-hour daily maternal separation from days 2 to 14 after birth to establish a model of visceral hypersensitivity, while the rats in the control and CRD groups received no treatment after birth. At 6 weeks after birth, the CRD and CRD+NMS groups received CRD stimulation. The streptavidin-biotin complex immunohistochemical method was used to determine the expression of BDNF in the spinal dorsal horn. The immunohistochemical score (IHS) was calculated based on the percentage of BDNF-positive cells and color intensity. The percentage of BDNF-positive cells in the spinal dorsal horn and IHS were analyzed by factorial analysis of variance.</p><p><b>RESULTS</b>The expression of BDNF was detected bilaterally in the spinal dorsal horn at different levels in the four groups. The percentage of BDNF-positive cells and IHS were significantly higher in the NMS and NMS+CRD groups than in the control group (P<0.05). The results of factorial analysis of variance indicated that NMS significantly increased the percentage of BDNF-positive cells in the spinal dorsal horn and IHS; a single CRD stimulation had no effects on the IHS of BDNF-positive cells in the spinal dorsal horn; there was no interaction between NMS and a single CRD stimulation.</p><p><b>CONCLUSIONS</b>The over-expression of BDNF in the spinal dorsal horn may be involved in high visceral hypersensitivity in young rats induce by NMS.</p>