The effects of simulated childbirth trauma on the gene expression of neurotransmitter receptors in the bladder of female rats

Abstract

Background/Purpose: To investigate the effects of simulated childbirth on the gene expression of parasympathetic muscarinic, purinergic (P2X), and neurokinin receptors of lower urinary tract in rats. Methods: In all, twenty-four primiparous pregnant Sprague-Dawley female rats were equally divided into three groups: (1). Control group; 8 rats, (2) intra-vaginal balloon dilation for 2 h group; 8 rats, (3) and for 4 h group; 8 rats. After balloon dilatation for 4 months, all rats were sacrificed. We analyzed the gene expression of parasympathetic muscarinic, purinergic (P2X), and neurokinin receptors by real-time quantitative PCR (q-PCR). We quantified pro-inflammatory cytokines of TNF-α and IL-6 by Enzyme-linked immunosorbent assays (ELISA). The urodynamic parameters and micturition frequency by cystometry (CMG) were recorded. Results: Our results showed that the balloon dilation significantly increased micturition frequency and modified peak micturition pressure compare to those in the control groups. Balloon dilation significantly decreased voiding interval and bladder volume compared to those in the control groups. Gene expressions of M3 muscarinic, P2X3 purinergic receptors, and significantly increased following balloon dilation for 2 hours and 4 hours than those in the control group. In addition, we found that NK1R and NK3R receptors were significantly decreased after balloon dilation compare to control group. The marked increase of TNF-α and IL-6 were also seen in the 2 balloon groups. Conclusion: The results of our study suggested that birth trauma may impair the function of urinary tract, this being partly related to the changes in the gene expression of the neurotransmitter receptors of the lower urinary tract.

Keywords

• Birth trauma
• Childbirth
• Neurokinin
• Pelvic floor dysfunction
• Purinergic