Neurotransmitters and Neuropeptides Expression in the Uterine Scar After Cesarean Section

Abstract

Peptides and neuropeptides influence the uterine disorders of healing or cicatrization, chronic pelvic pain and disorder of pregnancy, labor and puerperium. They also promote changes in the lower uterine segment (LUS) during pregnancy, labor and delivery. We investigated the tissue quantity of neurotensin (NT), neuropeptide tyrosin (NPY) and Protein Gene Product 9.5 (PGP 9.5) in women submitted to elective cesarean section (CS) and urgent CS. During surgery, authors biopsied tissue samples of vesico-uterine space (VUS) to detect nerve fibers, and compared them. VUS samples from 106 patients have been evaluated with light microscopy, immunochemistry and Immunohistochemistry, and finally by Quantimet Leica analyzer software. Significantly higher amount of nerve fibers, containing NT, NPY and PGP 9.5 have been found in VUS tissue samples obtained during the first elective CS and during the first urgent CS were respectively 5±0.7, 7±0.6 and 5±0.9 CU and 2.5±0.5, 3.6±0.4 and 3.5±0.9 CU (p<0.05). This neurotransmitter reduction should indicate the inflammatory damage of cervical tissue for LUS over distension in dystocic-prolonged labor before CS. These results may be correlated with the decrease of NT, NPY and PGP 9.5, responsible for an optimal healing and LUS functions. In our opinion, the presence of neuropeptides reduction in uterine samples of women undergoing urgent CS may be due to a prolonged fetal head station in LUS, with a tissue denervation, in consequence of both overdistension and inflammatory process of the dystocic LUS.

Keywords: Dystocia; cesarean section; intrapartum ultrasound; lower uterine segment; obstructed labor; pregnancy; uterine rupture; uterine scar.