Somatostatin, substance P and calcitonin gene-related peptide-positive intramural nerve structures of the human large intestine affected by carcinoma.

The aim of this study was to investigate the arrangement and chemical coding of enteric nerve structures in the human large intestine affected by cancer. Tissue samples comprising all layers of the intestinal wall were collected during surgery form both morphologically unchanged and pathologically altered segments of the intestine (n=15), and fixed by immersion in buffered paraformaldehyde solution. The cryostat sections were processed for double-labelling immunofluorescence to study the distribution of the intramural nerve structures (visualized with antibodies against protein gene-product 9.5) and their chemical coding using antibodies against somatostatin (SOM), substance P (SP) and calcitonin gene-related peptide (CGRP). The microscopic observations revealed distinct morphological differences in the enteric nerve system structure between the region adjacent to the cancer invaded area and the intact part of the intestine. In general, infiltration of the cancer tissue resulted in the gradual (depending on the grade of invasion) first decomposition and reduction to final partial or complete destruction and absence of the neuronal elements. A comparative analysis of immunohistochemically labeled sections (from the unchanged and pathologically altered areas) revealed a statistically significant decrease in the number of CGRP-positive neurons and nerve fibres in both submucous and myenteric plexuses in the transitional zone between morphologically unchanged and cancer-invaded areas. In this zone, a decrease was also observed in the density of SP-positive nerve fibres in all intramural plexuses. Conversely, the investigations demonstrated statistically insignificant differences in number of SP- and SOM-positive neurons and a similar density of SOM-positive nerve fibres in the plexuses of the intact and pathologically changed areas. The differentiation between the potential adaptive changes in ENS or destruction of its elements by cancer invasion should be a subject of further investigations

Ghrelin-immunoreactive cells in the gastrointestinal tract of hypertensive rats

Introduction. Ghrelin, an appetite-stimulating hormone secreted by the endocrine cells of the gastrointestinal (GI) tract, has recently been shown to affect the function of the cardiovascular system. This study aimed to assess the number and morphology of ghrelin-immunopositive (GhrIP) cells in the gastrointestinal tract of rats at different developmental phases of experimentally evoked renovascular hypertension. Material and methods. The study involved 40 rats divided into two groups: control (C; n = 20) and rats with experimentally induced hypertension (EH; n = 20). The Goldblatt model of two-kidneys, one clip (2K1C) was used to induce hypertension. Renovascular hypertension was maintained for either 3 (EH1 group; n = 10) or 42 (EH2 group; n = 10) days. Paraffin sections from the cardia, corpus and pylorus of the stomach, as well as from the duodenum, jejunum, ileum and colon were processed for peroxidase immunohistochemistry. Results. The number of GhrIP cells was significantly higher in the cardia and corpus of the stomach as well as the duodenum and jejunum of hypertensive rats compared to that found in the control animals. Conclusions. The increased number of GhrIP cells in the rat gastrointestinal tract after partial unilateral ligation of the renal artery suggests that renovascular hypertension may affect ghrelin secretion, which can contribute to the development of cardiovascular complications

Adrenergic, nitrergic and peptidergic innervation of the urethral muscle in the boar.

In this study, the innervation of the urethral muscle in adult male pigs was investigated using combined NADPH-diaphorase (NADPH-d) histochemistry and immunocytochemistry. Nerve fibres supplying the urethral muscle were found to show NADPH-d activity and they also expressed immunoreactivity to catecholamine synthesising enzymes including tyrosine hydoxylase (TH) and dopamine-beta-hydroxylase (DbetaH) as well as to: vasoactive intestinal polypeptide (VIP) and neuropeptide Y (NPY). Different subpopulations of the nerve fibres (NADPH-d positive, TH-, DbetaH-, VIP- and NPY-immunoreactive (IR), but also NADPH-d/VIP- and NADPH-d/NPY-IR) were disclosed. These nerve fibres were observed not only to run among muscle fibres of the urethral muscle, but also within extrinsic nerve trunks. Moreover, in the organ studied, numerous ganglia were found. The intramural ganglia, composed of a few to 30 neurons were located in the proximal, middle and distal regions of the pelvic urethra. In the vicinity of the urethral muscle, there were mainly small ganglia containing two to several neurons, but also larger ganglia consisting of up to tens neurons were encountered in the connective tissue surrounding the pelvic urethra. In the ganglia observed in the neighbourhood of the urethral muscle, different subpopulations of nerve cells were found, namely: catecholaminergic, nitrergic, VIP-IR, NPY-IR and also NADPH-d/DbetaH-, NADPH-d/VIP- and NADPH-d/NPY-positive. Possible sources of the innervation for this muscle were also discussed

The influence of inflammation on the expression of neuropeptides in the ileum-projecting primary sensory neurones in the pig

In the present study the ELISA test was used to investigate the influence of chemically-induced ileitis on the dorsal root ganglia (DRG) neurons in the pig. The preliminary retrograde fluorescent tracing study revealed that ileum-projecting sensory neurones (IPN) are located in the thoracic ganglia (Th; Th8-Th13). The ileum wall in experimental (E) pigs was subjected to multiple injection with 4% paraformaldehyde to induce inflammation, while in the control (C) animals the organ was injected with 0.1 M phosphate buffer. Three days later the DRGs (Th8-Th13) collected from all the animals were evaluated for VIP, SP, CGRP, NPY, GAL and SOM content with an ELISA test. It was found that the inflammation increased clearly the tissue level of SP, GAL and SOM

Distribution of efferent neurones innervating the oviduct in the pig

This study was aimed, by means of the retrograde tracing technique, at disclosing the distribution of efferent neurones innervating the porcine oviduct. The fluorescent retrograde tracer Fast Blue was injected into the wall of the right oviduct in six juvenile pigs during laparotomy performed under anaesthesia. After a recovery period of 3 weeks the animals were reanaesthetised, perfused with 4% buffered paraformaldehyde (pH 7.4) and different ganglia, thought to be potent sources of the efferent innervation, were collected. The occurrence and distribution of Fast Blue-positive neurones were studied in the sympathetic chain and prevertebral ganglia, including the coeliac-superior mesenteric ganglion complex, adrenal ganglion, aorticorenal ganglion, ovarian ganglion and inferior mesenteric ganglion. The labelled neurones were found only in the right, ipsilateral ganglia. The largest number of Fast Blue-positive neurones was found in the inferior mesenteric ganglion, ovarian ganglion and in the coeliac-superior mesenteric ganglion complex. In the inferior mesenteric ganglion, the Fast Blue-positive neurones showed a tendency to gather in the dorso-cranial and the dorso-caudal region of the ganglion, forming two discrete ”oviductal centres”. The aortico-renal and adrenal ganglion contained a smaller population of Fast Blue-positive nerve cell bodies. The smallest number of Fast Blue-positive neurones was found in the sympathetic chain ganglia (T14-L5). The localisation of Fast Blue-positive neurones in the sympathetic chain ganglia and prevertebral ganglia suggests that these nerve structures play a fundamental role in the efferent innervation of the porcine oviduc

Protective Effects of Pituitary Adenylate Cyclase-Activating Polypeptide (PACAP) Against Oxidative Stress in Zebrafish Hair Cells

Pituitary adenylate cyclase-activating polypeptide (PACAP) is a pleiotropic neuropeptide, with known antiapoptotic functions. Our previous in vitro study has demonstrated the ameliorative role of PACAP-38 in chicken hair cells under oxidative stress conditions, but its effects on living hair cells is now yet known. Therefore, the aim of the present study was to investigate in vivo the protective role of PACAP-38 in hair cells found in zebrafish (Danio rerio) sense organs-neuromasts. To induce oxidative stress the 5-day postfertilization (dpf) zebrafish larvae were exposed to 1.5 mM H2O2 for 15 min or 1 h. This resulted in an increase in caspase-3 and p-38 MAPK level in the hair cells as well as in an impairment of the larvae basic behavior. To investigate the ameliorative role of PACAP-38, the larvae were incubated with a mixture of 1.5 mM H2O2 and 100 nM PACAP-38 following 1 h preincubation with 100 nM PACAP-38 only. PACAP-38 abilities to prevent hair cells from apoptosis were investigated. Whole-mount immunohistochemistry and confocal microscopy analyses revealed that PACAP-38 treatment decreased the cleaved caspase-3 level in the hair cells, but had no influence on p-38 MAPK. The analyses of basic locomotor activity supported the protective role of PACAP-38 by demonstrating the improvement of the fish behavior after PACAP-38 treatment. In summary, our in vivo findings demonstrate that PACAP-38 protects zebrafish hair cells from oxidative stress by attenuating oxidative stress-induced apoptosis.Peer reviewe

Morphology and immunohistochemical characteristics of the otic ganglion in the chinchilla (Chinchilla laniger Molina)

Introduction. The available literature provides relatively little information on the morphology of the autonomic head ganglia in rodents including their neurochemical codding. Material and methods. Morphological investigations of the otic ganglion of the chinchilla were performed using the modified acetylcholinesterase method. The cellular structure was investigated with histological techniques and neurochemical properties were studied with the double-labelling immunofluorescence method. Results. Macromorphological investigations allowed the otic ganglion to be identified as a compact, oval agglomeration of neurons and nerve fibers. Multidimensional cross-sections revealed densely arranged neuronal perikarya and two populations of nerve cells differing in size were distinguished. The large cells (40–50 µm) accounted for about 80% of the neurons in the cross-sections. Moreover, a small number of intraganglionic nerve fibers was observed. Immunohistochemical staining revealed that over 85% of the neuronal cell bodies in the otic ganglion contained immunoreactivity to VAChT or ChAT. VIP-immunoreactive perikarya comprised approximately 10% of the ganglionic cells. Double staining revealed the presence of VAChT+ and NOS+ neurons which amounted to about 45% of the nerve cells in the otic ganglion. NOS+ only perikarya comprised approx. 15% of all the neurons. Immunoreactivity to enkephalins, substance P, somatostatin, and galanin was expressed in single nerve cell bodies and nerve fibers except numerous substance P+ intraganglionic nerve fibers. Some of them were stained also for CGRP. Single neurons stained for tyroxine hydroxylase. Conclusions. Our results, compared with findings in other rodent species suggest the existence of interspecies differences in the morphology, cellular structure, and immunohistochemical properties of the head autonomic ganglia in mammals

The Effect of Castration on Peripheral Autonomic Neurons Supplying Mammalian Male Genitourinary System

This review paper deals with the influence of androgens (testosterone) on pelvic autonomic pathways in male mammals. The vast majority of the relevant information has been gained in experiments involving castration (testosterone deprivation) performed in male rats, and recently, in male pigs. In both species, testosterone significantly affects the biology of the pathway components, including the pelvic neurons. However, there are great differences between rats and pigs in this respect. The most significant alteration is that testosterone deprivation accomplished a few days after birth results some months later in the excessive loss (approximately 90%) of pelvic and urinary bladder trigone intramural neurons in the male pig, while no changes in the number of pelvic neurons are observed in male rats (rats do not have the intramural ganglia). In the castrated pigs, much greater numbers of pelvic neurons than in the non-castrated animals express CGRP, GAL, VIP (peptides known to have neuroprotective properties), and caspase 3, suggesting that neurons die due to apoptosis triggered by androgen deprivation. In contrast, only some morpho-electrophysiological changes affecting neurons following castration are found in male rats. Certain clinicopathological consequences of testosterone deprivation for the functioning of urogenital organs are also discussed