Endometritis Changes the Neurochemical Characteristics of the Caudal Mesenteric Ganglion Neurons Supplying the Gilt Uterus

This study analyzed the influence of uterine inflammation on the neurochemical characteristics of the gilt caudal mesenteric ganglion (CaMG) uterus-supplying neurons. The horns of uteri were injected with retrograde tracer Fast Blue on day 17 of the first studied estrous cycle. Twenty-eight days later (the expected day 3 of the third studied estrous cycle), either saline or Escherichia coli suspension were administered into each uterine horn. Only the laparotomy was done in the control gilts. After 8 days, the CaMGs and uteri were harvested. The infected gilts presented a severe acute endometritis. In the CaMGs, the populations of uterine perikarya possessing dopamine-β-hydroxylase (DβH) and/or neuropeptide Y (NPY), somatostatin (SOM), galanin (GAL) and vasoactive intestinal polypeptide (VIP) were analyzed using the double immunofluorescence method. In the CaMG, bacterial injection decreased the total number of the perikarya (Fast Blue-positive), the small and large perikarya populations in the dorsal and central regions, and the small and large perikarya populations coded DβH+/GAL- and DβH-/NPY+. After bacterial treatment, there was an increase in the numbers of small and large perikarya coded DβH+/NPY+, small perikarya coded DβH+/GAL+ and DβH+/SOM- and large perikarya coded DβH+/VIP+. To summarize, uterine inflammation influences the neurochemical characteristics of the CaMG uterus-supplying neurons, which may be important for pathologically changed organ functions.

Distribution and immunohistochemical properties of autonomic neurons supplying the ovine hip joint capsule

Combined retrograde tracing and double labelling immunohistochemistry were applied to study the distribution and chemical coding of autonomic neurons projecting to the ovine hip joint capsule. As revealed by retrograde tracing, fast blue-positive autonomic neurons supplying the lateral side of the hip joint capsule and the medial side of the hip joint capsule were located within the lumbar and sacral of the ipsilateral sympathetic chain ganglia and within the caudal mesenteric ganglion. Immunohistochemistry revealed that nearly all (sympathetic chain ganglia: 96% and caudal mesenteric ganglion: 98.8%) the neurons were adrenergic in nature (positive for dopamine β-hydroxylase). Many retrogradely labelled neurons also displayed immunoreactivity to neuropeptide Y (approximately 34% of fast blue-positive neurons within caudal mesenteric ganglion and sympathetic chain ganglia). Populations of Met-Enk⁺ (20%) and Leu-Enk⁺ (6%) neurons were present only in the sympathetic chain ganglia while within caudal mesenteric ganglion no enkephalinergic-labelled neurons were noted. Only a small population (2.2%) of hip joint capsule-projecting neurons were Gal-IR and they were observed only within the caudal mesenteric ganglion. No cholinergic neurons involved in the innervation of the hip joint capsule were found. However, fast blue-positive nerve cell bodies were surrounded by numerous cholinergic nerve fibres often forming basket-like formations. Single Gal⁺ nerve fibres were found in the intraganglionic connective tissue. Substance P-positive or calcitonin gene-related peptide-positive intraganglionic nerve terminals were very numerous and formed “baskets” surrounding fast blue-positive perikarya within sympathetic chain ganglias and caudal mesenteric ganglion.

Changes in the tissue concentrations of several neuropeptides in porcine intestines and intestine-innervating ganglia in the course of porcine proliferative enteropathy

Inflammatory processes are associated with changes in the interplay of different pro- and anti-inflammatory factors, including neuropeptides, in tissue. This study was performed to investigate the influence of proliferative enteropathy on the concentration of several neuropeptides known to be involved in the regulation of the inflammatory process in porcine intestine and intestine-innervating ganglia. The concentration of galanin, vasoactive intestinal polypeptide, somatostatin, neuropeptide Y, substance P and calcitonin gene-related peptide were assayed with ELISA in the coeliac-superior mesenteric ganglion, inferior mesenteric ganglion, selected dorsal root ganglia, ileum and the descending colon in healthy and sick pigs. The concentrations of the studied neuropeptides were higher in sick animals. Statistically significant differences were found for coeliac-superior mesenteric ganglion (galanin, vasoactive intestinal polypeptide, somatostatin and neuropeptide Y), inferior mesenteric ganglion (galanin, somatostatin and neuropeptide Y), dorsal root ganglia (galanin, somatostatin, neuropeptide Y and calcitonin gene-related peptide), ileum (galanin and somatostatin) and the descending colon (galanin, somatostatin and neuropeptide Y). The data clearly show the influence of the inflammatory process on the concentration of some of the studied neuropeptides present in inflamed tissues and ganglia innervating the inflamed gut. These changes must be associated with the role the studied neuropeptides play in the inflammatory process.