Endometritis decreases the population of uterine neurons in the paracervical ganglion and changes the expression of sympathetic neurotransmitters in sexually mature gilts

Abstract

Abstract Background The focus of the study was to examine the impact of the inflamed uterus on the population of the paracervical ganglion (PCG) uterus-innervating perikarya and their chemical coding. Fast Blue retrograde tracer was injected into the wall of uterine horns on the 17th day of the first studied estrous cycle. After 28 days, either Escherichia coli suspension or saline was applied to the horns of the uterus, whereas the control group received laparotomy only. Eight days after the above-mentioned procedures, uterine cervices with PCG were collected. Both macroscopic and histopathologic examinations confirmed severe acute endometritis in the Escherichia coli-injected uteri. The double immunofluorescence method was used to analyze changes in the PCG populations coded with dopamine-β‐hydroxylase (DβH) and/or neuropeptide Y (NPY), somatostatin (SOM), vasoactive intestinal polypeptide (VIP) and neuronal isoform of nitric oxide synthase (nNOS). Results The use of Escherichia coli lowered the total number of Fast Blue-positive neurons. Moreover, an increase in DβH+/VIP+, DβH+/NPY+, DβH+/SOM + and DβH+/nNOS + expressing perikarya was noted. A rise in non-noradrenergic VIP-, SOM- and nNOS-immunopositive populations was also recorded, as well as a drop in DβH-positive neurotransmitter-negative neurons. Conclusions To sum up, inflammation of the uterus has an impact on the neurochemical properties of the uterine perikarya in PCG, possibly affecting the functions of the organ.